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Psychological Testing: Intelligence Quotient

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An intelligence quotient, or IQ, is a score derived from one of several different standardized tests designed to assess intelligence. The term “IQ,” from the German Intelligenz-Quotient, was devised by the German psychologist William Stern in 1912 as a proposed method of scoring children’s intelligence tests such as those developed by Alfred Binet and Théodore Simon in the early 20th Century⁠[1]. 

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Lewis Terman accepted that form of scoring, expressing a score as a quotient of “mental age” and “chronological age,” for his revision of the Binet-Simon test,⁠[1] the first version of the Stanford-Binet Intelligence Scales.Although the term “IQ” is still in common use, the scoring of modern IQ tests such as the Wechsler Adult Intelligence Scale is now based on standard scoring of the subject’s rank order on the test item content with the median score set to 100, and a standard deviation of 15, although not all tests adhere to that assignment of 15 IQ points to each standard deviation.

IQ scores have been shown to be associated with such factors as morbidity and mortality, parental social status,⁠[2] and, to a substantial degree, parental IQ. While the heritability of IQ has been investigated for nearly a century, controversy remains regarding the significance of heritability estimates,⁠[3][4] and the mechanisms of inheritance are still a matter of some debate[5].

IQ scores are used in many contexts: as predictors of educational achievement or special needs, by social scientists who study the distribution of IQ scores in populations and the relationships between IQ score and other variables, and as predictors of job performance and income.

The average IQ scores for many populations have been rising at an average rate of three points per decade since the early 20th century, a phenomenon called the Flynn effect. It is disputed whether these changes in scores reflect real changes in intellectual abilities, or merely methodological problems with past or present testing.

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Key takeaways

  • IQ scores summarize performance on standardized tests intended to assess aspects of intelligence.
  • Scores are used in educational and occupational contexts and are influenced by interacting developmental, environmental, and genetic factors.
  • Interpretation remains subject to debate about measurement, bias, and how fully tests capture human intellectual ability.

History

Psychometrics

Englishman Francis Galton, influenced by Darwinism, founded eugenics (and later psychometrics) to measure differences between upper and lower classes⁠[6]. Galton argued that due to heredity, white aristocrats were intellectually superior to other humans; nurture, meanwhile, played a lesser role in intellectual capacity⁠[7].

Clinical diagnostics

French psychologist Alfred Binet gave more weight to nurture, arguing that intelligence could be improved⁠[8]. Binet and fellow French psychologist Théodore Simon later developed the Binet-Simon test for measuring intellectual development or mental age to diagnose French children in need of special assistance classes⁠[9]. Binet-Simon tasks were diverse in order to neutralize individual differences in types of intelligence and provide a general measure.

Subject matter expert

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Neuroscience and clinical mental health

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Intelligence testing

English psychologist Charles Spearman, however, did not believe there were different types of intelligence⁠[10]. He devised a correlational formula to define a common intellective factor (which he called “general intelligence”), a factor that Binet argued did not exist⁠[11].

Intelligence quotient (IQ)

In 1910 the eugenics movement in the USA seized on the Binet-Simon test as means to give them credibility in diagnosing mental retardation after American psychologist Henry H. Goddard published a translation of it that same year⁠[12]. 

American psychologist Lewis Terman revised the Binet-Simon scale, implementing German psychologist William Stern‘s intelligence quotient (I.Q.) ratio of mental age to chronological age and used the resulting Stanford-Binet scale as a measure of general intelligence⁠[13].

World War I: large scale testing

A team of psychologists led by eugenicist Robert Yerkes assisted the US army to rapidly assess and assign huge numbers of personnel⁠[14]. They developed two group-administered intelligence tests for this purpose: an alpha test for literate personnel; and a beta for the illiterate. They successfully tested 1,726,000 recruits⁠[15]. 

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However, there was too little time for validity testing⁠[16] and not enough staff to administer tests correctly⁠[17]. Many officers distrusted the psychologists, accusing them of conducting research for their own purposes⁠[17] using culturally biased tests⁠[18]. 

Orders were issued that low test scores should not bar men from officer training and that a disability board should consider all discharges⁠[19]. The outcome was that 0.5% of recruits were discharged as mentally inferior, whilst Yerkes would have preferred to have discharged 3% whose results showed a mental age of under 10⁠[15].

In contrast, another team of psychologists led by Walter Dill Scott defined intelligence as a diverse complex of capacities, as Binet had. They stressed an individual differences approach emphasizing environmental adjustments of mental qualities as functions⁠[11]. 

Soon they developed a rating scale to classify and place enlisted men according to how they used their intelligence, not their base levels of intelligence⁠[18]. The army was enthusiastic about Scott’s classification of personnel. By the time the war ended they had already been incorporated into the military⁠[17] and had classified 3½ million men and assigned 973,858 to technical units⁠[15].

Post war to 1929

The army abolished Yerkes’ team after the war but employed two psychologists to continue intelligence testing research⁠[17]. However, a great deal of positive post war publicity on army psychological testing helped to make psychology a respected field⁠[20]. Subsequently there was an increase in jobs and funding in psychology⁠[21]. 

Group intelligence tests were developed for and became widely used in both primary and secondary schools, universities and industry⁠[17]. But controversy followed when one of Yerkes’ team, Goddard, admitted that they had been guilty of bad logic in finding that 45% of army recruits had a mental age of 12 or less⁠[22]. 

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In addition, there was no agreement on what the intelligence tests measured,⁠[23][24][25] and the publication of racial differences in scores⁠[26] led to much criticism that environmental influences on score had not been considered⁠[23][27].

Wechsler’s innovation in scoring

Modern IQ scores compare performance with a reference group. The average is usually set at 100, with a standard deviation of 15[28].

The modern IQ scale is a mathematical transformation of a raw score on an IQ test, based on the rank of that score in a normalization sample. This procedure was pioneered by David Wechsler.

Modern scores are sometimes referred to as “deviation IQs,” while older method age-specific scores are referred to as “ratio IQs.”⁠[29] IQ scales of either kind are ordinal scales and thus IQ points are not units of measurement⁠[30][31][32][33].

The two scoring methodologies yield similar results near the population median, but the older ratio IQs yielded far higher scores for high-scoring (gifted) children. Current IQ tests do not yield such high scores, as recent validation studies have shown that concerns about ceiling effects in identifying gifted children are exaggerated⁠[34]. 

In any event error of estimation is greatest for scores above the population median⁠[35] and likely to overestimate the true score (in the sense of formal testing theory) of a test-taker who obtains a score above the median⁠[36].

Since the publication of the Wechsler Adult Intelligence Scale (WAIS), almost all intelligence scales have adopted the deviation method of scoring. The use of this scoring method makes the term “intelligence quotient” an inaccurate description, mathematically speaking, but the term “IQ” still enjoys colloquial usage,⁠[37] and is used to label the standard scoring of most cognitive ability tests currently in use.

Reliability

Psychometricians generally regard IQ tests as highly reliable (in the technical sense of testing theory) and clinical psychologists generally regard them as having sufficient validity for many clinical purposes.

A test-taker's score on any one IQ test is surrounded by an error band that shows, to a specified degree of confidence, what the test-taker's true score (in that same technical sense) is likely to be. Test-takers can have varying scores on differing occasions of taking IQ tests and can vary in scores on different IQ tests taken at the same age⁠[39][40][41].

The General Intelligence Factor (g)

Main article: General intelligence factor

There are many different kinds of IQ tests using a wide variety of methods. Some tests are visual, some are verbal, some tests only use of abstract-reasoning problems, and some tests concentrate on arithmetic, spatial imagery, reading, vocabulary, memory or general knowledge⁠[42].

The psychologist Charles Spearman early this century made the first formal factor analysis of correlations between the tests. He found that a single common factor explained for the positive correlations among tests. This is an argument still accepted in principle by many psychometricians.

Spearman named it g for \"general intelligence factor.\" In any collections of IQ tests, by definition the test that best measures g is the one that has the highest correlations with all the others. Most of these g-loaded tests typically involve some form of abstract reasoning.

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Therefore Spearman and others have regarded g as the perhaps genetically determined real essence of intelligence. This is still a common but not proven view. Other factor analyses of the data with different results are possible. Some psychometricians regard g as a statistical artifact. The accepted best measure of g is Raven's Progressive Matrices which is a test of visual reasoning⁠[42].

Trends in IQ

Main article: Flynn effect

Since the early twentieth century, raw scores on IQ tests have increased in most parts of the world⁠[43][44][45]. When a new version of an IQ test is normed, the standard scoring is set so that performance at the population median results in a score of IQ 100.

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The phenomenon of rising raw score performance means that if test-takers are scored by a constant standard scoring rule, IQ test scores have been rising at an average rate of around three IQ points per decade. This phenomenon was named the Flynn effect in the book The Bell Curve after James R. Flynn, the author who did the most to bring this phenomenon to the attention of psychologists⁠[46][47].

Researchers have been exploring the issue of whether the Flynn effect is equally strong on performance of all kinds of IQ test items, whether the effect may have ended in some developed nations, whether or not there are social subgroup differences in the effect, and what possible causes of the effect might be⁠[48].

Flynn's observation has prompted much new research in psychology and \"demolish some long-cherished beliefs, and raise a number of other interesting issues along the way.\"⁠[44]

Environmental and genetic influences and malleability

Environmental influences

See also: Health and intelligence and environment and intelligence

Environmental factors play a role in determining IQ. Proper childhood nutrition appears critical for cognitive development; malnutrition can lower IQ. For example, iodine deficiency causes a fall, in average, of 12 IQ points⁠[49]. It is expected that average IQ in third world countries will increase dramatically if the deficiencies of iodine and other micronutrients are eradicated.

A recent study found that the FADS2 gene, along with breastfeeding, adds about seven IQ points to those with the \"C\" version of the gene. Those with the \"G\" version of the FADS2 gene see no advantage⁠[50][51].

Musical training in childhood may also increase IQ⁠[52]. Recent studies have shown that training in using one's working memory may increase IQ⁠[53][54].

Family environment

Some studies in the developed world have shown that inherited personality traits cause non-related children raised in the same family (\"adoptive siblings\") to be as different as children raised in different families⁠[55].[not in citation given][56] There are some family effects on the IQ of children, accounting for up to a quarter of the variance; however, by adulthood, this correlation approaches zero⁠[57].

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For IQ, adoption studies show that, after adolescence, adoptive siblings are no more similar in IQ than strangers (IQ correlation near zero), while full siblings show an IQ correlation of 0.6.

Twin studies reinforce this pattern: monozygotic (identical) twins raised separately are highly similar in IQ (0.86), more so than dizygotic (fraternal) twins raised together (0.6) and much more than adoptive siblings⁠[55].[not in citation given] However these results make no correction for the social and emotional effects frequently associated with adoption.

Possible bias in older studies

Stoolmiller (1999)⁠[58] found that the range restriction of family environments that goes with adoption, that adopting families tend to be more similar on, for example, socio-economic status than the general population, suggests a possible underestimation of the role of the shared family environment in previous studies.

Corrections for range correction applied to adoption studies indicate that socio-economic status could account for as much as 50% of the variance in IQ⁠[58].

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However, the effect of restriction of range on IQ for adoption studies was examined by Matt McGue and colleagues, who wrote that \"restriction in range in parent disinhibitory psychopathology and family socio-economic status had no effect on adoptive-sibling correlations [in] IQ\"⁠[59].

Eric Turkheimer and colleagues (2003)⁠[60] studied the \"Massive IQ Gains in 14 Nations: What IQ Tests Really Measure\"
heritability of IQ in impoverished US families. Results demonstrated that in small children the proportions of IQ variance attributable to genes and environment vary nonlinearly with socio-economic status.

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In a 2003 study of young U.S. twins, estimated genetic and shared-environment contributions varied with family socioeconomic status. These estimates describe that study population and do not determine an individual’s abilities[60].

Maternal (fetal) environment

A meta-analysis, by Devlin and colleagues in Nature (1997),⁠[5] of 212 previous studies evaluated an alternative model for environmental influence and found that it fits the data better than the 'family-environments' model commonly used.

The shared maternal (fetal) environment effects, often assumed to be negligible, account for 20% of covariance between twins and 5% between siblings, and the effects of genes are correspondingly reduced, with two measures of heritability being less than 50%.

Bouchard and McGue reviewed the literature in 2003, arguing that Devlin's conclusions about the magnitude of heritability is not substantially different from previous reports and that their conclusions regarding prenatal effects stands in contradiction to many previous reports⁠[63]. They write that:

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Chipuer et al. and Loehlin conclude that the postnatal rather than the prenatal environment is most important. The Devlin et al. conclusion that the prenatal environment contributes to twin IQ similarity is especially remarkable given the existence of an extensive empirical literature on prenatal effects. Price (1950), in a comprehensive review published over 50 years ago, argued that almost all MZ twin prenatal effects produced differences rather than similarities. As of 1950 the literature on the topic was so large that the entire bibliography was not published. It was finally published in 1978 with an additional 260 references. At that time Price reiterated his earlier conclusion. Research subsequent to the 1978 review largely reinforces Price's hypothesis.

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Dickens and Flynn model

Dickens and Flynn⁠[64] postulate that the arguments regarding the disappearance of the shared family environment should apply equally well to groups separated in time. This is contradicted by the Flynn effect. Changes here have happened too quickly to be explained by genetic heritable adaptation.

This paradox can be explained by observing that the measure \"heritability\" includes both a direct effect of the genotype on IQ and also indirect effects where the genotype changes the environment, in turn affecting IQ. That is, those with a higher IQ tend to seek out stimulating environments that further increase IQ.

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The direct effect can initially have been very small but feedback loops can create large differences in IQ. In their model an environmental stimulus can have a very large effect on IQ, even in adults, but this effect also decays over time unless the stimulus continues (the model could be adapted to include possible factors, like nutrition in early childhood, that may cause permanent effects).

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The Flynn effect can be explained by a generally more stimulating environment for all people. The authors suggest that programs aiming to increase IQ would be most likely to produce long-term IQ gains if they taught children how to replicate outside the program the kinds of cognitively demanding experiences that produce IQ gains while they are in the program and motivate them to persist in that replication long after they have left the program⁠[64][65].

Genetic influences

Main article: Heritability of IQ

Various studies find the heritability of IQ between 0.4 and 0.8 in the United States;⁠[66][67][68] that is, depending on the study, a little less than half to substantially more than half of the variation in IQ among the children studied was estimated to be due to genetic variation.

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Heritability measures the proportion of variation that can be attributed to genes within any measured population (however defined), and not the extent that genes contribute to intelligence.

It should also be noted that the idea that genetic and environmental influences on intelligence are independent is not necessarily accepted, or as Jeremy Freese says \"The lucidity of Lewontin's arguments has historically proven no match for the allure of overly simple characterizations of outcomes as being x% due to genes and (1 – x)% not due to genes\". That means that genes affect environment and environment affects genes⁠[69][70][71][72][73][74].

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A heritability in the range of 0.4 to 0.8 implies that IQ is \"substantially\" heritable, that is, some substantial part of the variation within a population is caused at least in part by genes.

The effect of restriction of range on IQ was examined by Matt McGue and colleagues, who wrote that \"restriction in range in parent disinhibitory psychopathology and family SES had no effect on adoptive-sibling correlations ... IQ.\"⁠[59] On the other hand, a 2003 study by Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. Gottesman demonstrated that the proportions of IQ variance attributable to genes and environment vary with socioeconomic status.

They found that in impoverished families, 60% of the variance in IQ \"in a sample of 7-year-old twins\" is accounted for by the shared environment, and the contribution of genes was close to zero⁠[75].

It is reasonable to expect that genetic influences on traits like IQ should become less important as one gains experiences with age.

However, the opposite occurs⁠[76]. Heritability measures in infancy are as low as 20%, around 40% in middle childhood, and as high as 80% in adulthood⁠[76]. The American Psychological Association's 1995 task force on \"Intelligence: Knowns and Unknowns\" concluded that within the white population the heritability of IQ is \"around .75.\"

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The Minnesota Study of Twins Reared Apart, a multiyear study of 100 sets of reared-apart twins which was started in 1979, concluded that about 70% of the variance in IQ was found to be associated with genetic variation.

Some of the correlation of IQs of twins may be a result of the effect of the maternal environment before birth, shedding some light on why IQ correlation between twins reared apart is so robust⁠[5]. There are a number of points to consider when interpreting heritability:

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  • A high heritability does not mean that the environment has no effect on the development of a trait, or that learning is not involved. Vocabulary size, for example, is very substantially heritable (and highly correlated with general intelligence) although every word in an individual's vocabulary is learned. In a society in which plenty of words are available in everyone's environment, especially for individuals who are motivated to seek them out, the number of words that individuals actually learn depends to a considerable extent on their genetic predispositions⁠[67].
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  • A common error is to assume that because something is heritable it is necessarily unchangeable. As previously noted, heritable traits can depend on learning, and they may be subject to other environmental effects as well. The value of heritability can change if the distribution of environments (or of genes) in the population is substantially altered. For example, an impoverished or suppressive environment could fail to support the development of a trait, and hence restrict individual variation. Differences in variation of heritability are found between developed and developing nations. This could affect estimates of heritability⁠[67]. Another example is Phenylketonuria which previously caused mental retardation for everyone who had this genetic disorder. Today, this can be prevented by following a modified diet.
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  • On the other hand, there can be effective environmental changes that do not change heritability at all. If the environment relevant to a given trait improves in a way that affects all members of the population equally, the mean value of the trait will rise without any change in its heritability (because the differences among individuals in the population will stay the same). This has evidently happened for height: the heritability of stature is high, but average heights continue to increase⁠[67].
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  • Even in developed nations, high heritability of a trait within a given group has no necessary implications for the source of a difference between groups⁠[67][77].
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IQ and the brain

Main article: Neuroscience and intelligence

In 2004, Richard Haier, professor of psychology in the Department of Pediatrics and colleagues at University of California, Irvine and the University of New Mexico used MRI to obtain structural images of the brain in 47 normal adults who also took standard IQ tests.

The study demonstrated that general human intelligence appears to be based on the volume and location of gray matter tissue in the brain, and also demonstrated that, of the brain's gray matter, only about 6 percent appeared to be related to IQ⁠[78].[non-primary source needed]

A large lesion study examined 227 people with focal brain damage and 165 healthy controls using Raven’s Advanced Progressive Matrices. Participants with frontal lesions, particularly on the right, performed worse; participants with non-frontal lesions did not differ from controls. This supports the importance of right frontal regions for performance on this fluid-reasoning task, without reducing all forms of intelligence to a single brain area⁠[79].

A study involving 307 children (aged from six to nineteen) measuring the size of brain structures using magnetic resonance imaging (MRI) and measuring verbal and non-verbal abilities has been conducted (Shaw et al. 2006)⁠[80].[non-primary source needed] This study indicated that higher intelligence is not directly related to cortical thickness, but rather the change in cortical thickness over time.

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A study of cortical development found that the relationship between cortical thickness and intelligence changed with age[80].

There is \"a highly significant association\" between the CHRM2 gene and intelligence according to a 2006 Dutch family study. The study concluded that there was an association between the CHRM2 gene on chromosome 7 and Performance IQ, as measured by the Wechsler Adult Intelligence Scale-Revised.

The Dutch family study used a sample of 667 individuals from 304 families⁠[83].[non-primary source needed] A similar association was found independently in the Minnesota Twin and Family Study (Comings et al. 2003) and by the Department of Psychiatry at the Washington University⁠[84].[non-primary source needed]

Significant injuries isolated to one side of the brain, especially those occurring at a young age, may not significantly affect IQ⁠[85].

Studies reach conflicting conclusions regarding the controversial idea that brain size correlates positively with IQ. Jensen and Reed claim no direct correlation exists in nonpathological subjects⁠[86]. A more recent meta-analysis suggests otherwise⁠[87].

Malleability (mutability or changeability)

Although IQ is believed by many to be immutable,⁠[88] recent research suggests that certain mental activities can change the brain's ability to process information, leading to the conclusion that intelligence can be altered or changed over time. The brain is now properly understood to be neuroplastic and hence far more amenable to change than once was thought.

Studies into the neuroscience of animals indicate that challenging activities can produce changes in gene expression patterns of the brain. (Training Degus to Use Rakes⁠[89] and Iriki's earlier research with macaque monkeys indicating brain changes.)

A study on young adults published in April 2008 by a team from the Universities of Michigan and Bern supports the possibility of the transfer of fluid intelligence from specifically designed working memory training[90].

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Further research will be needed to determine nature, extent and duration of the proposed transfer:⁠[91] Among other questions, it remains to be seen whether the results extend to other kinds of fluid intelligence tests than the matrix test used in the study, and if so, whether, after training, fluid intelligence measures retain their correlation with educational and occupational achievement or if the value of fluid intelligence for predicting performance on other tasks changes. It is also unclear whether the training is durable of extended periods of time.

The peak capacity for both fluid intelligence and crystallized intelligence is 26 years. This is followed by a slow decline⁠[92].

Validity and social significance

While IQ is sometimes treated as an end unto itself, scholarly work on IQ focuses to a large extent on IQ's validity, that is, the degree to which IQ correlates with outcomes such as job performance, social pathologies, or academic achievement.

Different IQ tests differ in their validity for various outcomes.[citation needed] Traditionally, correlation for IQ and outcomes is viewed as a means to also predict performance; however readers should distinguish between prediction in the hard sciences and the social sciences.

Health

Main article: Health and intelligence

People with a higher IQ have generally lower adult morbidity and mortality. Post-Traumatic Stress Disorder,⁠[93] and schizophrenia[94][95] are less prevalent in higher IQ bands. People in the midsts of a major depressive episode have been shown to have a lower IQ than when without symptoms and lower cognitive ability than people without depression of equivalent verbal intelligence⁠[96][97].

A study of 11,282 individuals in Scotland who took intelligence tests at ages 7, 9 and 11 in the 1950s and 1960s, found an \"inverse linear association\" between childhood IQ scores and hospital admissions for injuries in adulthood. The association between childhood IQ and the risk of later injury remained even after accounting for factors such as the child's socioeconomic background⁠[98].

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Research in Scotland has also shown that a 15-point lower IQ meant people had a fifth less chance of living to 76, while those with a 30-point disadvantage were 37% less likely than those with a higher IQ to live that long⁠[99].

A decrease in IQ has also been shown as an early predictor of late-onset Alzheimer's Disease and other forms of dementia. In a 2004 study, Cervilla and colleagues showed that tests of cognitive ability provide useful predictive information up to a decade before the onset of dementia⁠[100].

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However, when diagnosing individuals with a higher level of cognitive ability, in this study those with IQs of 120 or more,⁠[101] patients should not be diagnosed from the standard norm but from an adjusted high-IQ norm that measured changes against the individual's higher ability level.

In 2000, Whalley and colleagues published a paper in the journal Neurology, which examined links between childhood mental ability and late-onset dementia. The study showed that mental ability scores were significantly lower in children who eventually developed late-onset dementia when compared with other children tested⁠[102].

Several factors can lead to significant cognitive impairment, particularly if they occur during pregnancy and childhood when the brain is growing and the blood-brain barrier is less effective. Such impairment may sometimes be permanent, or may sometimes be partially or wholly compensated for by later growth. Several harmful factors may also combine, possibly causing greater impairment.

Preventing toxic exposures is one way to protect cognitive development. WHO identifies lead as especially harmful to children: exposure can affect brain development, attention, learning, and IQ, even without obvious early symptoms. There is no known safe blood lead concentration, so reducing exposure is a public-health priority⁠[103].

In terms of the effect of one's intelligence on health, in one British study, high childhood IQ was shown to correlate with one's chance of becoming a vegetarian in adulthood⁠[104]. In another British study, high childhood IQ was shown to inversely correlate with the chances of smoking⁠[105].

Other tests

Intelligence-test scores and educational experience are related. A meta-analysis of quasi-experimental studies also found evidence that additional schooling can improve cognitive-test performance, so the relationship should not be interpreted solely as intelligence determining educational success⁠[107].

Ritchie and Tucker-Drob combined 42 datasets involving more than 600,000 participants. Across the designs studied, an additional year of education was associated with an estimated one to five IQ points of improvement. This is a study-level estimate, not a guaranteed change for any individual⁠[107].

School performance

The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that wherever it has been studied, children with high scores on tests of intelligence tend to learn more of what is taught in school than their lower-scoring peers. The correlation between IQ scores and grades is about .50.

However, this means that they explain only 25% of the variance. Achieving good grades depends on many factors other than IQ, such as \"persistence, interest in school, and willingness to study\" (p. 81).

Job performance

According to Frank Schmidt and John Hunter, \"for hiring employees without previous experience in the job the most valid predictor of future performance is general mental ability.\"⁠[108] The validity of IQ as a predictor of job performance is above zero for all work studied to date, but varies with the type of job and across different studies, ranging from 0.2 to 0.6⁠[109].

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While IQ is more strongly correlated with reasoning and less so with motor function⁠[110] IQ-test scores predict performance ratings in all occupations⁠[108].

That said, for highly qualified activities (research, management) low IQ scores are more likely to be a barrier to adequate performance, whereas for minimally-skilled activities, athletic strength (manual strength, speed, stamina, and coordination) are more likely to influence performance⁠[108]. It is largely mediated through the quicker acquisition of job-relevant knowledge that IQ predicts job performance.

In establishing a causal direction to the link between IQ and work performance, longitudinal studies by Watkins and others suggest that IQ exerts a causal influence on future academic achievement, whereas academic achievement does not substantially influence future IQ scores⁠[111].

Treena Eileen Rohde and Lee Anne Thompson write that general cognitive ability but not specific ability scores predict academic achievement, with the exception that processing speed and spatial ability predict performance on the SAT math beyond the effect of general cognitive ability⁠[112].

The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that other individual characteristics such as interpersonal skills, aspects of personality etc. are probably of equal or greater importance, but at this point we do not have equally reliable instruments to measure them⁠[67].

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More recently, others argue that since most professional tasks are now standardized or automated, and ranked IQ is a stable measurement over time with high correlation with many positive personal traits from the general population, it is the best tool to help determine hiring and job placement at any stage in a career, independently of experience, personality bias or any formal training one may acquire.[citation needed]

Income

Some researchers claim that \"in economic terms it appears that the IQ score measures something with decreasing marginal value. It is important to have enough of it, but having lots and lots does not buy you that much.\"⁠[113][114]

Other studies show that ability and performance for jobs are linearly related, such that at all IQ levels, an increase in IQ translates into a concomitant increase in performance⁠[115]. Charles Murray, coauthor of The Bell Curve, found that IQ has a substantial effect on income independently of family background⁠[116].

Taking the above two principles together, very high IQ produces very high job performance, but no greater income than slightly high IQ. Studies also show that high IQ is related to higher net worth⁠[117].

The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that IQ scores account for about one-fourth of the social status variance and one-sixth of the income variance. Statistical controls for parental SES eliminate about a quarter of this predictive power. Psychometric intelligence appears as only one of a great many factors that influence social outcomes⁠[67].

Some studies claim that IQ only accounts for a sixth of the variation in income because many studies are based on young adults (many of whom have not yet completed their education).

On pg 568 of The g Factor, Arthur Jensen claims that although the correlation between IQ and income averages a moderate 0.4 (one sixth or 16% of the variance), the relationship increases with age, and peaks at middle age when people have reached their maximum career potential. In the book, A Question of Intelligence, Daniel Seligman cites an IQ income correlation of 0.5 (25% of the variance).

A 2002 study⁠[118] further examined the impact of non-IQ factors on income and concluded that an individual's location, inherited wealth, race, and schooling are more important as factors in determining income than IQ.

Other correlations with IQ

In addition, IQ and its correlation to health, violent crime, gross state product, and government effectiveness are the subject of a 2006 paper in the publication Intelligence. The paper breaks down IQ averages by U.S. states using the federal government's National Assessment of Educational Progress math and reading test scores as a source⁠[119].

There is a correlation of -0.19 between IQ scores and number of juvenile offences in a large Danish sample; with social class controlled, the correlation dropped to -0.17.

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Similarly, the correlations for most \"negative outcome\" variables are typically smaller than 0.20, which means that test scores are associated with less than 4% of their total variance. It is important to realize that the causal links between psychometric ability and social outcomes may be indirect.

Children with poor scholastic performance may feel alienated. Consequently, they may be more likely to engage in delinquent behavior, compared to other children who do well⁠[67].

IQ is also negatively correlated with certain diseases.

Tambs et al.[120] found that occupational status, educational attainment, and IQ are individually heritable; and further found that \"genetic variance influencing educational attainment ... contributed approximately one-fourth of the genetic variance for occupational status and nearly half the genetic variance for IQ.\" In a sample of U.S. siblings, Rowe et al.[121] report that the inequality in education and income was predominantly due to genes, with shared environmental factors playing a subordinate role.

A 2022 meta-analysis covering 89 studies and 201,457 participants found a small negative association between intelligence measures and religiosity. Its strength varied with measurement choices and the populations studied. This group-level correlation does not establish that religious identity causes differences in intelligence or determine any individual’s ability⁠[122].

Group differences

Among the most controversial issues related to the study of intelligence is the observation that intelligence measures such as IQ scores vary between ethnic and racial groups and sexes. While there is little scholarly debate about the existence of some of these differences, their causes remain highly controversial both within academia and in the public sphere.

Sex

Main article: Sex and intelligence

Men and women have statistically significant differences in average scores on tests of particular abilities⁠[123][124]. Studies also illustrate consistently greater variance in the performance of men compared to that of women⁠[125].

Interpreting comparisons between groups requires attention to what a test measures and the circumstances in which it is taken. Noba’s overview describes multiple possible influences on intellectual-test performance, including social expectations, learning opportunities, and test-taking strategies. A difference in a selected sample does not establish a simple, universal ranking of men’s and women’s intelligence⁠[126].

Race

Main articles: History of the race and intelligence controversy and Race and intelligence

The 1996 Task Force investigation on Intelligence sponsored by the American Psychological Association concluded that there are significant variations in I.Q. across races⁠[67].

The problem of determining the causes underlying this variation relates to the question of the contributions of \"nature and nurture\" to I.Q. Psychologists such as Alan S. Kaufman[128] and Nathan Brody⁠[129] and statisticians such as Bernie Devlin⁠[130] point out there are insufficient data to conclude that this is because of genetic influences. One of the most notable authors arguing for a strong genetic influence on this score difference is Arthur Jensen.

\n

In contrast, Richard Nisbett, the long-time director of the Culture and Cognition program at the University of Michigan, argues that environmental influences are not sufficiently taken into account in Jensen's writings⁠[131].

Age

For decades, it has been reported in practitioners' handbooks and textbooks on IQ testing that IQ declines with age after the beginning of adulthood. However, later researchers pointed out that this phenomenon is related to the Flynn effect and is in part a cohort effect rather than a true aging effect.

There have been a variety of studies of IQ and aging since the norming of the first Wechsler Intelligence Scale drew attention to IQ differences in different age groups of adults. Current consensus is that fluid intelligence generally declines with age after early adulthood, while crystallized intelligence remains intact.

Both cohort effects (the birth year of the test-takers) and practice effects (test-takers taking the same form of IQ test more than once) must be controlled for to gain accurate data. It is unclear whether any lifestyle intervention can preserve fluid intelligence into older ages⁠[132].

Public policy

The examples and perspective in this article deal primarily with USA and do not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (August 2010)

Main article: Intelligence and public policy

In the United States, certain public policies and laws regarding military service,⁠[133][134] education, public benefits,⁠[135] capital punishment,⁠[189] and employment incorporate an individual's IQ into their decisions.

However, in the case of Griggs v. Duke Power Co. in 1971, for the purpose of minimizing employment practices that disparately impacted racial minorities, the U.S. Supreme Court banned the use of IQ tests in employment, except in very rare cases⁠[137].

Internationally, certain public policies, such as improving nutrition and prohibiting neurotoxins, have as one of their goals raising, or preventing a decline in, intelligence.

Criticism and views

Binet

Alfred Binet, a French psychologist, did not believe that IQ test scales qualified to measure intelligence. He neither invented the term \"intelligence quotient\" nor supported its numerical expression.[citation needed] He stated:

\n

The scale, properly speaking, does not permit the measure of intelligence, because intellectual qualities are not superposable, and therefore cannot be measured as linear surfaces are measured.

\n

—Binet, 1905

\n

Binet had designed the Binet-Simon intelligence scale in order to identify students who needed special help in coping with the school curriculum. He argued that with proper remedial education programs, most students regardless of background could catch up and perform quite well in school. He did not believe that intelligence was a measurable fixed entity.

The Mismeasure of Man

Some scientists dispute psychometrics entirely. In The Mismeasure of Man, Harvard professor and paleontologist Stephen Jay Gould argued that intelligence tests were based on faulty assumptions and showed their history of being used as the basis for scientific racism. He criticized

\n

…the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups—races, classes, or sexes—are innately inferior and deserve their status.(pp. 24–25)

\n

He spends much of the book criticizing the concept of IQ, including a historical discussion of how the IQ tests were created and a technical discussion of why g is simply a mathematical artifact. Later editions of the book included criticism of The Bell Curve.

Bernard Davis wrote that while the nonscientific reviews of The Mismeasure of Man were almost uniformly laudatory, the reviews in the scientific journals were almost all highly critical⁠[139].

Peter H. Schönemann

Psychologist Peter Schönemann has been a persistent critic of IQ, calling it \"the IQ myth\"⁠[140]. He argued that Spearman's g is a flawed theory and the high heritability estimates of IQ are based on false assumptions⁠[141].

[editEric Turkheimer
] Relation between IQ and intelligence

See also: Intelligence

According to Dr. C. George Boeree of Shippensburg University, intelligence is a person's capacity to (1) acquire knowledge (i.e. learn and understand), (2) apply knowledge (solve problems), and (3) engage in abstract reasoning. It is the power of one's intellect, and as such is clearly a very important aspect of one's overall well-being. Psychologists have attempted to measure it for well over a century.[citation needed]

IQ is associated with intelligence, but may fail to act as an accurate measure of \"intelligence\" in its broadest sense. This is partly because IQ tests only examine particular areas embodied by the broadest notion of \"intelligence\", failing to account for certain areas which are also associated with \"intelligence\" such as creativity or emotional intelligence.[citation needed]

Several other ways of measuring intelligence have been proposed. Daniel Schacter, Daniel Gilbert, and others have moved beyond general intelligence and IQ as the sole means to describe intelligence⁠[142].

Test bias

See also: Stereotype threat

The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that IQ tests as predictors of social achievement are not biased against people of African descent since they predict future performance, such as school achievement, similarly to the way they predict future performance for people of European descent⁠[67].

However, IQ tests may well be biased when used in other situations. A 2005 study stated that \"differential validity in prediction suggests that the WAIS-R test may contain cultural influences that reduce the validity of the WAIS-R as a measure of cognitive ability for Mexican American students,\"⁠[143] indicating a weaker positive correlation relative to sampled white students.

\n

Other recent studies have questioned the culture-fairness of IQ tests when used in South Africa⁠[144][145]. Standard intelligence tests, such as the Stanford-Binet, are often inappropriate for children with autism; the alternative of using developmental or adaptive skills measures are relatively poor measures of intelligence in autistic children, and may have resulted in incorrect claims that a majority of children with autism are mentally retarded⁠[146].

Outdated methodology

Modern test evaluation requires evidence that supports the intended interpretation and use of scores. The joint Standards for Educational and Psychological Testing emphasize validity, reliability or measurement precision, and fairness; evidence for one purpose does not automatically justify a different use⁠[147].

The view of the American Psychological Association

In response to the controversy surrounding The Bell Curve, the American Psychological Association's Board of Scientific Affairs established a task force in 1995 to write a report on the state of intelligence research which could be used by all sides as a basis for discussion. The full text of the report is available through several websites⁠[67][148].

In this paper the representatives of the association regret that IQ-related works are frequently written with a view to their political consequences: \"research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications\".

The task force concluded that IQ scores do have high predictive validity for individual differences in school achievement. They confirm the predictive validity of IQ for adult occupational status, even when variables such as education and family background have been statistically controlled.

They found that individual differences in intelligence are substantially influenced by genetics and that both genes and environment, in complex interplay, are essential to the development of intellectual competence.

The report stated that a number of biological factors, including malnutrition, exposure to toxic substances, and various prenatal and perinatal stressors, result in lowered psychometric intelligence under at least some conditions. The task force agrees that large differences do exist between the average IQ scores of blacks and whites, and that these differences cannot be attributed to biases in test construction.

\n

The task force suggests that explanations based on social status and cultural differences are possible, and that environmental factors have raised mean test scores in many populations. Regarding genetic causes, they noted that there is not much direct evidence on this point, but what little there is fails to support the genetic hypothesis.

The APA journal that published the statement, American Psychologist, subsequently published eleven critical responses in January 1997, several of them arguing that the report failed to examine adequately the evidence for partly-genetic explanations.

High IQ societies

Main article: High IQ society

There are social organizations, some international, which limit membership to people who have scores as high as or higher than the 98th percentile on some IQ test or equivalent. Mensa International is perhaps the most well known of these. There are other groups requiring a score above the 98th percentile.

Popular culture usage

Many websites and magazines use the term IQ to refer to technical or popular knowledge in a variety of subjects not related to intelligence, including sex,⁠[149] poker,⁠[150] and American football,⁠[151] among a wide variety of other topics. These tests are generally not standardized and do not fit within the normal definition of intelligence.

\n

Intelligence tests such as the Wechsler Adult Intelligence Scale, Wechsler Intelligence Scale for Children, Stanford-Binet, Woodcock-Johnson III Tests of Cognitive Abilities, or the Kaufman Assessment Battery for Children-II, to name some of the best constructed, are not merely placing a test taker's score within the norm, as presumably are the thousands of alleged \"IQ Tests\" found on the internet, but they are also testing factors (e.g., fluid and crystallized intelligence, working memory, and the like) that were previously found to represent pure measures of intelligence using factor analysis.

This claim may not be made for the hundreds of online tests marketing themselves as IQ Tests, a distinction that may be unfortunately lost upon the public taking them.

Reference charts

Main article: IQ reference chart

IQ reference charts are tables suggested by test publishers to divide intelligence ranges in various categories.

See also

References

Notes

References

  1. Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. p. 15. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive.
  2. Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report.
  3. Johnson, W., Turkheimer, E., Gottesman, I. I., & Bouchard, T. J., Jr. (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18(4), 217–220. doi: 10.1111/j.1467-8721.2009.01639.x. PubMed Central. SAGE Journals. National Library of Medicine. Accessed October 10 2026.
  4. Turkheimer, E. (2008, Spring). A Better Way to Use Twins for Developmental Research. LIFE Newsletter, 2–5. Max Planck Institute for Human Development. University of Virginia. Accessed June 29 2010.
  5. Devlin, B., Daniels, M., & Roeder, K. (1997, July 31). The heritability of IQ. Nature, 388(6641), 468–471. doi: 10.1038/41319. PubMed. Accessed October 10 2026.
  6. Gillham, N. W. (2001). Sir Francis Galton and the birth of eugenics. Annual Review of Genetics, 35, 83-101.
  7. Galton, F. (1865). Hereditary talent and character. Classics in the history of psychology. psychclassics.yorku.ca. Accessed October 10 2026.
  8. Binet, A. (1916). New methods for the diagnosis of the intellectual level of subnormals. In The development of intelligence in children (E. S. Kite, Trans.). Publications of the Training School at Vineland. Original work published 1905. York University — Classics in the History of Psychology. Accessed July 10 2010.
  9. Wallin, J. E. W. (1911). The new clinical psychology and the psycho-clinicist. Journal of Educational Psychology, 2(4), 191-210.
  10. Spearman, C. (1904). General intelligence. objectively determined and measured. American Journal of Psychology, 15(2), 201-293.
  11. Mayrhauser, R. T. V. (1992). The mental testing community and validity: A prehistory. American Psychologist, 47(2), 244-253.
  12. Richardson, T. E. (2003). Howard Andrew Knox and the origins of performance testing on Ellis Island, 1212-1216. History of Psychology, 6(2), 143-170.
  13. Terman, L. M., Lyman, G., Ordahl, G., Ordahl, L., Galbreath, N., and Talbert, W. (1915). The Stanford revision of the Binet-Simon scale and some results from its application to 1000 non-selected children. The Journal of Educational Psychology, 6(9), 551-562.
  14. Carmichael, L. (1957). Robert Mearns Yerkes. The Psychological Review, 64(1), 1-7.
  15. Yerkes, R. (1919). Report of the psychology committee of the national research council. The Psychological Review, 26(2), 83-149.
  16. Driskell, J. E., & Olmstead, B. (1989). Psychology and the military: Research applications and trends. American Psychologist, 44(1), 43-54.
  17. Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581.
  18. Keene, J. D. (1994). Intelligence and morale in the army of a democracy: The genesis of military psychology during the First World War. Military Psychology, 6(4), 235-253.
  19. Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581.
  20. Kennedy, C. H., & McNeil, J. A. (2006). A history of military psychology. In C. H. Kennedy, E. A. Zillmer (Eds.), Military Psychology: Clinical and Operational Applications (pp.1-17). New York: Guilford Publications.
  21. Katzell, R. A., & Austin, J. T. (1992). From then to now: the development of industrial-organizational psychology in the United States. Journal of Applied Psychology. 77(6), 803-835.
  22. Goddard, H. H. (1921). The sub-normal mind versus the abnormal. Journal of Abnormal Psychology, 16(1), 47-54.
  23. Alper, T. G., & Boring, E. G. (1944). Intelligence-test scores of northern and southern white and negro recruits in 1918. Journal of Abnormal & Social Psychology, 39(4), 471-474.
  24. Thurstone, L. L. (1934). The vectors of mind. Psychological Review, 41, 1-32.
  25. Terman, L. M. (1924). The mental test as a psychological method. The Psychological Review, 31(2), 93-117.
  26. Garrett, H. E. (1945). A note on the intelligence scores of negroes and whites in 1918. Journal of Abnormal & Social Psychology, 40(3), 344-346.
  27. Rembis, M. A. (2004). I ain't been reading while on parole. Experts, mental tests, and eugenic commitment law in Illinois, 1890-1940. History of Psychology, 7(3), 225-247.
  28. IQ — APA Dictionary of Psychology. (n.d.). American Psychological Association.
  29. Pinneau, Samuel R. (1961). Changes in Intelligence Quotient Infancy to Maturity: New Insights from the Berkeley Growth Study with Implications for the Stanford-Binet Scales and Applications to Professional Practice. Boston: Houghton Mifflin.
  30. Mussen, Paul Henry. (1973). Psychology: An Introduction. Lexington (MA): Heath. p. 363. ISBN 0-669-61383-7. \"The I.Q. is essentially a rank; there are no true \"units\" of intellectual ability.\". en.wikipedia.org. en.wikipedia.org.
  31. Truch, Steve. (1993). The WISC-III Companion: A Guide to Interpretation and Educational Intervention. Austin (TX): Pro-Ed. p. 35. ISBN 0890795851. \"An IQ score is not an equal-interval score, as is evident in Table A.4 in the WISC-III manual.\". en.wikipedia.org. en.wikipedia.org.
  32. Bartholomew, D. J. (2004). Measuring Intelligence: Facts and Fallacies. Cambridge University Press, p. 50. ISBN 9780521544788. Cambridge University Press.
  33. Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. pp. 30–31. ISBN 0-19-852367-X. \"In the jargon of psychological measurement theory, IQ is an ordinal scale, where we are simply rank-ordering people. It is not even appropriate to claim that the 10-point difference between IQ scores of 110 and 100 is the same as the 10-point difference between IQs of 160 and 150\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  34. Perleth, Christoph; Schatz, Tanja; Mönks, Franz J. (2000). Early Identification of High Ability. In Heller, Kurt A. Mönks, Franz J. Sternberg, Robert J. et al. International Handbook of Giftedness and Talent (2nd ed.). Amsterdam: Pergamon. p. 301. ISBN 978-0-08-043796-5. \"norm tables that provide you with such extreme values are constructed on the basis of random extrapolation and smoothing but not on the basis of empirical data of representative samples.\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  35. Terman, Lewis Madison; Merrill, Maude A. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. \"it becomes clear that the probable error of an I.Q. score is not a constant amount, but a variable which increases as I.Q. increases. It has frequently been noted in the literature that gifted subjects show greater I.Q. fluctuation than do clinical cases with low I.Q.'s. we now see that this trend is inherent in the I.Q. technique itself, and might have been predicted on logical grounds.\". en.wikipedia.org.
  36. Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. ISBN 0-13-236273-2. \"obtained scores tend to underestimate universe scores for the bottom half of the distribution and overestimate universe scores for the top half of the distribution\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  37. Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. p. 346. ISBN 0-13-236273-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  38. Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  39. Terman, Lewis Madison; Merrill, MaudeA. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. p. 44. en.wikipedia.org.
  40. Anastasi, A., & Urbina, S. (1997). Psychological Testing. 7th ed., pp. 326–327. Prentice Hall. ISBN 9780023030857. Pearson. Accessed October 10 2026.
  41. Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  42. Neisser U. (1997). Rising Scores on Intelligence Tests. American Scientist 85: 440–7. americanscientist.org.
  43. Neisser, Ulric, ed. (1998). The Rising Curve: Long-Term Gains in IQ and Related Measures. APA Science Volume Series. Washington (DC): American Psychological Association. ISBN 978-1-55798-503-3. en.wikipedia.org. en.wikipedia.org.
  44. Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive.
  45. Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.
  46. Flynn, James R. title=The Mean IQ of Americans: Massive Gains 1932 to 1978. (1984). Psychological Bulletin. 95: 29–51. doi. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026.
  47. Flynn, James R. (1987, March). Massive IQ Gains in 14 Nations: What IQ Tests Really Measure. Psychological Bulletin 101 (2): 171–191. doi:. American Psychological Association. psycnet.apa.org:443. en.wikipedia.org. psycnet.apa.org:443. psycnet.apa.org:443. Accessed August 22 2010.
  48. Zhou, X., Grégoire, J., & Zhu, J. (2010). The Flynn Effect and the Wechsler Scales. In L. G. Weiss, D. H. Saklofske, D. Coalson, et al. (Eds.), WAIS-IV clinical use and interpretation: Scientist-practitioner perspectives. Academic Press. ISBN 9780123750358. ScienceDirect.
  49. Qian M, Wang D, Watkins WE, et al. (2005). The effects of iodine on intelligence in children: a meta-analysis of studies conducted in China. Asia Pacific Journal of Clinical Nutrition 14 (1): 32–42. PMID 15734706. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.
  50. Gene governs IQ boost from breastfeeding. (n.d.). physorg.com. Accessed October 10 2026.
  51. Caspi, A., Williams, B., Kim-Cohen, J., Craig, I. W., Milne, B. J., Poulton, R., Schalkwyk, L. C., Taylor, A., Werts, H., & Moffitt, T. E. (2007). Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism. Proceedings of the National Academy of Sciences, 104(47), 18860–18865. doi: 10.1073/pnas.0704292104. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.
  52. Schellenberg, E. G. (2004). Music lessons enhance IQ. Psychol Sci 15(8): 511-4.
  53. (Klingberg et al., 2002). (n.d.).
  54. Jaeggi SM, Buschkuehl M, Jonides J, Perrig WJ. (2008). Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Sci. U.S.A. 105 (19): 6829–6833. doi:. PMID 18443283. PMC 2383929. pnas.org. pnas.org. en.wikipedia.org. National Library of Medicine. en.wikipedia.org. PubMed Central. Accessed October 10 2026.
  55. Plomin et al. (2001, 2003).
  56. Harris. (1998).
  57. Bouchard TJ. (1998). Genetic and environmental influences on adult intelligence and special mental abilities. Hum. Biol. 70 (2): 257–279. PMID 9549239. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.
  58. Stoolmiller, M. (1999). Implications of the restricted range of family environments for estimates of heritability and nonshared environment in behavior-genetic adoption studies. Psychological Bulletin, 125(4), 392–409. doi: 10.1037/0033-2909.125.4.392. PubMed. APA PsycNet.
  59. McGue, M. et al. (2007). The Environments of Adopted and Non-adopted Youth: Evidence on Range Restriction From the Sibling Interaction and Behavior Study (SIBS). Behavior Genetics 37 (3): 449. doi:. PMID 17279339. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  60. Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  61. Socioeconomic status modifies heritability of iq in young children Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. (2003). Gottesman. Psychological Science 14 (6), 623–628. 2003. blackwell-synergy.com.
  62. Bouchard, T.J.; McGue, M. (2003). Genetic and environmental influences on human psychological differences. Journal of Neurobiology 54 (1): 4. doi:. PMID 12486697. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  63. Dickens and Flynn. (2001).
  64. Dickens, W. T., & Flynn, J. R. (2002). The IQ Paradox: Still Resolved. Psychological Review, 109(4). Brookings Institution.
  65. Plomin R, Pedersen NL, Lichtenstein P, McClearn GE. (1994, May). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics 24 (3): 207–15. doi:. PMID 7945151. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  66. Neisser et al. (1995, August 7). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. webspace.ship.edu. en.wikipedia.org. Accessed October 10 2026.
  67. Bouchard TJ, Lykken DT, McGue M, Segal NL, Tellegen A. (1990). Sources of human psychological differences: the Minnesota Study of Twins Reared Apart. Science 250 (4978): 223–228. doi:. PMID 2218526. sciencemag.org. science.org. en.wikipedia.org. National Library of Medicine.
  68. Commentary: The analysis of variance and the social complexities of genetic causation. (2006). by Jeremy Freese International Journal of Epidemiology 35(3):534-536. Oxford Academic.
  69. Commentary: Heritability estimates—long past their sell-by date. (2006). by Steven P R Rose Int. J. Epidemiol. 35: 525-527. Oxford Academic.
  70. Commentary: The analysis of variance is an analysis of causes (of a very circumscribed kind). (2006). Int. J. Epidemiol. 35: 527-531. Oxford Academic.
  71. Commentary: The attainability of causal knowledge of genetic effects in complex human traits. (2006). Int. J. Epidemiol. 35: 531-534. Oxford Academic.
  72. Commentary: Statistical analysis or biological analysis as tools for understanding biological causes. (2006). Int. J. Epidemiol. '35:' 536-537. Oxford Academic.
  73. The analysis of variance and the analysis of causes. (2006). Int. J. Epidemiol. 35: 520-525. Oxford Academic.
  74. Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychological Science 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  75. Bouchard, TJ. (2004). Genetic influence on human psychological traits - A survey. Current Directions in Psychological Science 13 (4): 148–151. doi. SAGE Journals. Accessed October 10 2026.
  76. See: Ethnic Differences in Children's Intelligence Test Scores: Role of Economic Deprivation, Home Environment, and Maternal Characteristics. (n.d.).
  77. Brain Research Institute, UC Irvine College of Medicine. (n.d.). Human Intelligence Determined by Volume and Location of Gray Matter Tissue in Brain. Brain Research Institute, UC Irvine College of Medicine. sciencedaily.com. Accessed October 10 2026.
  78. Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.
  79. Shaw P, Greenstein D, Lerch J, et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  80. Wade, N. (2006). Scans Show Different Growth for Intelligent Brains. The New York Times. The New York Times. Accessed August 6 2006.
  81. Gosso MF, van Belzen M, de Geus EJ, et al. (2006). Association between the CHRM2 gene and intelligence in a sample of 304 Dutch families. Genes, Brain and Behavior 5 (8): 577–584. doi:. PMID 17081262. en.wikipedia.org. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  82. Dick DM, Aliev F, Kramer J, et al. (2007). Association of CHRM2 with IQ: converging evidence for a gene influencing intelligence. Behav. Genet. 37 (2): 265–272. doi:. PMID 17160701. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  83. Bava, S., Ballantyne, A. O., & Trauner, D. A. (2005). Disparity of verbal and performance IQ following early bilateral brain damage. Cognitive and Behavioral Neurology, 18(3), 163–170. doi: 10.1097/01.wnn.0000178228.61938.3e. PubMed. Ovid. Accessed October 10 2026.
  84. Reed, T.E., & Jensen, A.R. (1993). Cranial capacity: new Caucasian data and comments on Rushton's claimed Mongoloid-Caucasoid brain-size differences. Intelligence, 17, 423-431.
  85. McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33, 337–346. ScienceDirect.
  86. Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, pp. 220–222. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.
  87. Okanoya K, Tokimoto N, Kumazawa N, Hihara S, Iriki A. (2008). Tool-use training in a species of rodent: the emergence of an optimal motor strategy and functional understanding. PLoS ONE 3 (3): e1860. doi:. PMID 18365015. PubMed Central. PLOS. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  88. Jaeggi, S. M., Buschkuehl, M., Jonides, J., & Perrig, W. J. (2008). Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences, 105(19), 6829–6833. doi: 10.1073/pnas.0801268105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.
  89. Sternberg, R. J. (2008). Increasing fluid intelligence is possible after all. Proceedings of the National Academy of Sciences, 105(19), 6791–6792. doi: 10.1073/pnas.0803396105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.
  90. McArdle J J, Ferrer-Caja E, Hamagami F, Woodcock RW. (2002). Comparative longitudinal structural analyses of the growth and decline of multiple intellectual abilities over the life span. Dev. Psychol. 38: 115–142. PMID 11806695 Based on a sample of 1200 US individuals aged 2–95 years representative of both genders of major ethnic groups and all education levels. National Library of Medicine.
  91. Breslau N, Lucia VC, Alvarado GF. (2006). Intelligence and other predisposing factors in exposure to trauma and posttraumatic stress disorder: a follow-up study at age 17 years. Arch. Gen. Psychiatry 63 (11): 1238–1245. doi:. PMID 17088504. JAMA Network. en.wikipedia.org. National Library of Medicine.
  92. Zinkstok, J. R., de Wilde, O., van Amelsvoort, T. A. M. J., Tanck, M. W., Baas, F., & Linszen, D. H. (2007). Association between the DTNBP1 gene and intelligence: a case-control study in young patients with schizophrenia and related disorders and unaffected siblings. Behavioral and Brain Functions, 3, 19. doi: 10.1186/1744-9081-3-19. PubMed Central. Springer. National Library of Medicine. Accessed October 10 2026.
  93. Woodberry KA, Giuliano AJ, Seidman LJ. (2008). Premorbid IQ in schizophrenia: a meta-analytic review. Am J Psychiatry 165 (5): 579–587. doi:. PMID 18413704. PsychiatryOnline. en.wikipedia.org. National Library of Medicine.
  94. Sackeim HA, Freeman J, McElhiney M, Coleman E, Prudic J, Devanand DP. (1992). Effects of major depression on estimates of intelligence. J Clin Exp Neuropsychol 14 (2): 268–288. doi:. PMID 1572949. Taylor & Francis. en.wikipedia.org. National Library of Medicine.
  95. Mandelli L, Serretti A, Colombo C, et al. (2006). Improvement of cognitive functioning in mood disorder patients with depressive symptomatic recovery during treatment: an exploratory analysis. Psychiatry Clin. Neurosci. 60 (5): 598–604. doi:. PMID 16958944. blackwell-synergy.com. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  96. Debbie A. Lawlor, University of Bristol, Heather Clark, University of Aberdeen, David A. Leon, London School of Hygiene & Tropical Medicine. (2006). Associations Between Childhood Intelligence and Hospital Admissions for Unintentional Injuries in Adulthood: The Aberdeen Children of the 1950s Cohort Study. American Journal of Public Health, December 2006. ajph.org. Accessed January 10 2007.
  97. Whalley, L. J., & Deary, I. J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. BMJ, 322(7290), 819. doi: 10.1136/bmj.322.7290.819. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.
  98. Cervilla, J., Prince, M., Joels, S., Lovestone, S., & Mann, A. (2004, August). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Journal of Neurology, Neurosurgery & Psychiatry, 75(8), 1100–1106. doi: 10.1136/jnnp.2003.028076. PubMed Central. BMJ. National Library of Medicine.
  99. American Psychological Association. (2004, January 4). More sensitive test norms better predict which high IQ adults might develop Alzheimer's. Press release. American Psychological Association. American Psychological Association. Accessed August 6 2006.
  100. Whalley LJ, Starr JM, Athawes R, Hunter D, Pattie A, Deary IJ. (2000). Childhood mental ability and dementia. Neurology 55 (10): 1455–1459. PMID 11094097. neurology.org. en.wikipedia.org. National Library of Medicine.
  101. World Health Organization. (n.d.). Lead poisoning. WHO. World Health Organization. Accessed October 10 2026.
  102. Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.
  103. Taylor, MD; Hart, Carole L.; Smith, George Davey; Starr, John M.; Hole, David J.; Whalley, Lawrence J.; Wilson, Valerie; Deary, Ian J. (2005). Childhood IQ and social factors on smoking behaviour, lung function and smoking-related outcomes in adulthood: linking the Scottish Mental Survey 1932 and the Midspan studies. British Journal of Health Psychology 10 (3): 399–401. doi:. PMID 16238855. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  104. Frey MC, Detterman DK. (2004, June). Scholastic Assessment or g? The relationship between the Scholastic Assessment Test and general cognitive ability. Psychological Science 15 (6): 373–8. doi:. PMID 15147489. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  105. Ritchie, S. J., & Tucker-Drob, E. M. (2018). How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 29(8), 1358–1369. labs.la.utexas.edu. Accessed October 10 2026.
  106. Schmidt, Frank L.; Hunter, John E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin 124: 262. doi. psycnet.apa.org:443.
  107. Hunter, J. E. and Hunter, R. F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96, 72–98.
  108. Warner MH, Ernst J, Townes BD, Peel J, Preston M. (1987). Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R. J Clin Exp Neuropsychol 9 (5): 545–562. doi:. PMID 3667899. Taylor & Francis. en.wikipedia.org. National Library of Medicine.
  109. Marley W. Watkins, Pui-Wa Lei and Gary L. Canivez. (2007). Psychometric intelligence and achievement: A cross-lagged panel analysis, Intelligence, 35, 59-68.
  110. Treena Eileen Rohde and Lee Anne Thompson. (2007). Predicting academic achievement with cognitive ability, Intelligence, 35, 83-92.
  111. Detterman and Daniel, 1989. (n.d.).
  112. Hunt, E. (1995, July–August). The role of intelligence in modern society. American Scientist, section: Nonlinearities in Intelligence. Archived May 21, 2006. Internet Archive. americanscientist.org. Accessed October 10 2026.
  113. Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology, 75:297–300.
  114. Murray, Charles. (1998). Income Inequality and IQ, AEI Press PDF. aei.org. Accessed October 10 2026.
  115. Henderson, M. (2007, April 25). Brains don't make you rich, IQ study finds. The Times (London). Accessed May 5 2010. Original online source unavailable.
  116. Bowles, S., & Gintis, H. (2002). The inheritance of inequality. Journal of Economic Perspectives, 16(3), 3–30. doi: 10.1257/089533002760278686. American Economic Association.
  117. McDaniel, M. A. (2006). Estimating state IQ: Measurement challenges and preliminary correlates. Intelligence, 34(6), 607–619. doi: 10.1016/j.intell.2006.08.007. ScienceDirect.
  118. Tambs K, Sundet JM, Magnus P, Berg K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav Genet. 1989 Mar;19(2):209–22. PMID 2719624. National Library of Medicine.
  119. Rowe, D. C., W. J. Vesterdal, and J. L. Rodgers. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. University of Arizona, 1997.
  120. Dürlinger, F., & Pietschnig, J. (2022). Meta-analyzing intelligence and religiosity associations: Evidence from the multiverse. PLOS ONE, 17(2), e0262699. PLOS. Accessed October 10 2026.
  121. Douglas N. (2006). Jackson and J. Philippe Rushton, Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test, Intelligence, Volume 34, Issue 5, September–October 2006, Pages 479-486.
  122. Lynn, R., & Irwing, P. (2004). Sex differences on the Progressive Matrices: A meta-analysis. Intelligence, 32, 481-498.
  123. Deary, I.J., Irwing, P., Der, G., & Bates, T.C. (2007). Brother–sister differences in the g factor in intelligence: Analysis of full, opposite-sex siblings from the NLSY1979. Intelligence, 35(5): 451-456.
  124. Biswas-Diener, R. (n.d.). Intelligence. Noba. nobaproject.com. Accessed October 10 2026.
  125. Publications. (n.d.). rlynn.co.uk. Accessed October 10 2026.
  126. Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, p. 173. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.
  127. Brody, Nathan chapter=To g or Not to g—That Is the Question. (2005). Wilhelm, Oliver & Engle, Randall W. (Eds.). ed. Handbook of Understanding and Measuring Intelligence. Thousand Oaks (CA): SAGE Publications. en.wikipedia.org.
  128. Bernie Devlin, Stephen E. Fienberg, Daniel P. Resnick & Kathryn Roeder, ed. (1997). Intelligence, Genes, and Success: Scientists Respond to the Bell Curve. New York (NY): Springer Verlag. ISBN 0-38798234-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  129. Nisbett, R. E. (2009). Intelligence and How to Get It: Why Schools and Cultures Count. W. W. Norton. ISBN 9780393065053. W. W. Norton.
  130. Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, Chapter 8. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.
  131. [Referenced web resource]. (n.d.). (PDF). rand.org. Accessed October 10 2026.
  132. Kilburn, M. R., Hanser, L. M., & Klerman, J. A. (1998). Estimating AFQT scores for National Educational Longitudinal Study (NELS) respondents. RAND Corporation, report MR-818-OSD/A, Chapter 2. RAND Corporation.
  133. Social Security Administration. (n.d.). ssa.gov. Accessed October 10 2026.
  134. Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.
  135. Lemann, N. (1999, March 29). The IQ meritocracy. TIME. TIME.
  136. Davis, B. D. (1983, Fall). Neo-Lysenkoism, IQ, and the press. The Public Interest, 73, 41–59. National Affairs — The Public Interest archive.
  137. Models and muddles of heritability. (n.d.). Genetica, 99, 97-108. PubMed.
  138. Schönemann, P. H. (1983). Do IQ tests really measure intelligence? Commentary, The Behavioral and Brain Sciences, 6, 311-313.
  139. The Waning of I.Q. (n.d.). by David Brooks, The New York Times. The New York Times. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.
  140. Verney, S. P., Granholm, E., Marshall, S. P., Malcarne, V. L., & Saccuzzo, D. P. (2005). Culture-fair cognitive ability assessment: Information processing and psychophysiological approaches. Assessment, 12(3), 303–319. doi: 10.1177/1073191105276674. PubMed.
  141. Shuttleworth-Edwards AB, Kemp RD, Rust AL, Muirhead JG, Hartman NP, Radloff SE. (2004). Cross-cultural effects on IQ test performance: a review and preliminary normative indications on WAIS-III test performance. J Clin Exp Neuropsychol 26 (7): 903–920. doi:. PMID 15742541. Taylor & Francis. en.wikipedia.org. National Library of Medicine.
  142. Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons. (2004). 1*, Leah K. Hamilton1, Betty R. Onyura1 and Andrew S. Winston International Journal of Selection and Assessment Volume 14 Issue 3 Page 278 - September 2006. blackwell-synergy.com.
  143. Edelson, M. G. (2006). Are the majority of children with autism mentally retarded? a systematic evaluation of the data. Focus on Autism and Other Developmental Disabilities, 21(2), 66–83. doi: 10.1177/10883576060210020301. SAGE Journals. Accessed October 10 2026.
  144. American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (2014). Standards for Educational and Psychological Testing. American Educational Research Association. testingstandards.net. Accessed October 10 2026.
  145. Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report.
  146. Planned Parenthood Sex IQ. (2008). Archived from the original on July 6, 2008. Internet Archive. plannedparenthood.org. Accessed October 10 2026.
  147. NL Holdem Poker IQ Test. (n.d.). testyourpoker.com. Accessed October 10 2026.
  148. American Football IQ. (n.d.). footballiqtest.com. Accessed October 10 2026.
  149. Carroll, J.B. (1993). Human cognitive abilities: A survey of factor-analytical studies. New York: Cambridge University Press. ISBN 0-521-38275-0. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  150. Lahn, B.T.; Ebenstein, L. (2009). Let's celebrate human genetic diversity. nature (journal) 461 (7265): 726–728. doi:. PMID 19812654. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  151. Coward, W.M.; Sacket, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology 75: 297–300. doi. en.wikipedia.org. psycnet.apa.org:443.
  152. Duncan, J. et al. (2000). A neural basis for general intelligence. Science 289 (5478): 457–60. doi:. PMID 10903207. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine.
  153. Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.
  154. Flynn, J.R. (1999). Searching for Justice: The discovery of IQ gains over time. (PDF). American Psychologist 54: 5–20. doi. sites.stat.columbia.edu. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026.
  155. Frey, M.C.; Detterman, D.K. (2003). Scholastic assessment or g? The relationship between the scholastic assessment test and general cognitive ability. Psychological Science 15 (6): 373–378. doi:. PMID 15147489. en.wikipedia.org. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  156. Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.
  157. Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). What Are Intelligence and Creativity? Psychology 2e. OpenStax, Rice University. openstax.org. Accessed October 10 2026.
  158. Gottfredson, L.S. (1998). The general intelligence factor. (PDF). Scientific American Presents 9 (4): 24–29. udel.edu. Accessed October 10 2026.
  159. Gottfredson, L.S. (2005). Suppressing intelligence research: Hurting those we intend to help. In Wright, R.H. and Cummings, N.A (Eds.) (PDF). Destructive trends in mental health: The well-intentioned path to harm. New York: Taylor and Francis. pp. 155–186. ISBN 0-415-95086-4. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.
  160. Gottfredson, L.S. (2006). Social consequences of group differences in cognitive ability (Consequencias sociais das diferencas de grupo em habilidade cognitiva). In Flores-Mendoza, C.E. and Colom, R. (Eds.) (PDF). Introdução à psicologia das diferenças individuais. Porto Alegre, Brazil: ArtMed Publishers. pp. 155–186. ISBN 8-536-30621-1. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.
  161. Gould, S.J. (1996). W. W. Norton & Co. ed. The Mismeasure of Man: Revised and Expanded Edition. New-York: Penguin. ISBN 0140258248. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  162. Gray, J.R.; Chabris, C.F.; Brave,r T.S. (2003). Neural mechanisms of general fluid intelligence. Nat. Neurosci. 6 (3): 316–22. doi:. PMID 12592404. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  163. Gray JR, Thompson PM. (2004). Neurobiology of intelligence: science and ethics. Nat. Rev. Neurosci. 5 (6): 471–82. doi:. PMID 15152197. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  164. Rosalind Franklin University. (2021). Massive study led by Rosalind Franklin University neuroscientists reveals few differences between men and women’s brains. Rosalind Franklin University. rosalindfranklin.edu. Accessed October 10 2026.
  165. Harris, J.R. (1998). The nurture assumption : why children turn out the way they do. New York (NY): Free Press. ISBN 0-684-84409-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  166. Hunt, E. (2001). Multiple views of multiple intelligence. [Review of Intelligence Reframed: Multiple Intelligences for the 21st Century.]. Contemporary Psychology 46: 5–7.
  167. Jensen, A.R. (1979). Bias in mental testing. New York (NY): Free Press. ISBN 0-029-16430-3. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  168. Jensen, A.R. (1979). The g Factor: The Science of Mental Ability. Wesport (CT): Praeger Publishers. ISBN 0-275-96103-6. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  169. Jensen, A.R. (2006). Clocking the Mind: Mental Chronometry and Individual Differences. Elsevier. ISBN 0-080-44939-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  170. Kaufman, A.S. (2009). IQ Testing 101. New York (NY): Springer Publishing. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.
  171. Klingberg, T.; Forssberg, H.; Westerberg, H. (2002). Training of working memory in children with Attention-deficit/hyperactivity disorder (ADHD). J Clin Exp Neuropsychol 24 (6): 781–91. doi:. PMID 12424652. Taylor & Francis. en.wikipedia.org. National Library of Medicine.
  172. McClearn, G.E. et al. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science 276 (5318): 1560–1563. doi:. PMID 9171059. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine.
  173. Bratsberg, B., & Rogeberg, O. (2018). Flynn effect and its reversal are both environmentally caused. Proceedings of the National Academy of Sciences, 115(26), 6674–6678. PubMed Central. Accessed October 8 2026.
  174. Murray, C. (1998). (PDF). Income Inequality and IQ. Washington (DC): AEI Press. ISBN 0-8447-7094-9. aei.org. en.wikipedia.org. en.wikipedia.org. aei.org. Accessed October 10 2026.
  175. Noguera, P.A. (2001). Racial politics and the elusive quest for excellence and equity in education. Motion Magazine. Article # ER010930002. inmotionmagazine.com. Accessed October 10 2026.
  176. Plomin, R.; DeFries, J.C.; Craig, I.W.; McGuffin, P. (2003). Behavioral genetics in the postgenomic era. Washington (DC): American Psychological Association. ISBN 1-557-98926-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed August 6 2006.
  177. Plomin, R.; DeFries, J.C.; McClearn, G.E.; McGuffin, P. (2000). Behavioral genetics. (4th ed.). New York (NY): Worth Publishers Scientific American Presents. ISBN 0-716-75159-3. en.wikipedia.org. en.wikipedia.org.
  178. Rowe, D.C.; Vesterdal, W.J.; Rodgers, J.L. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. [verification needed]. en.wikipedia.org.
  179. Schoenemann PT, Sheehan MJ, Glotzer LD. (2005, February). Prefrontal white matter volume is disproportionately larger in humans than in other primates. Nature Neuroscience 8 (2): 242–52. doi:. PMID 15665874. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  180. Shaw, P. et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  181. Tambs, K.; Sundet, J.M.; Magnus, P.; Berg, K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav. Genet. 19 (2): 209–22. doi:. PMID 2719624. en.wikipedia.org. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  182. Thompson, P.M. et al. (2001). Genetic influences on brain structure. Nat. Neurosci. 4 (12): 1253–1258. doi:. PMID 11694885. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.
  183. Wechsler, D. (1997). Wechsler Adult Intelligence Scale. (3rd ed.). San Antonia (TX): The Psychological Corporation.
  184. Wechsler, D. (2003). Wechsler Intelligence Scale for Children. (4th ed.). San Antonia (TX): The Psychological Corporation.
  185. Weiss, V. (2009). National IQ means transformed from Programme for International Student Assessment (PISA) Scores. The Journal of Social, Political and Economic Studies 31 (1): 71–94. mpra.ub.uni-muenchen.de. en.wikipedia.org. Accessed October 10 2026.
  186. The Return of Determinism? (n.d.).

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","text":"Home Library Assessments & Diagnosis Psychological Testing: Intelligence Quotient Psychological Testing: Intelligence Quotient Published on May 31, 2024 · Updated on November 20, 2025 An intelligence quotient, or IQ, is a score derived from one of several different standardized tests designed to assess intelligence. The term “IQ,” from the German Intelligenz-Quotient, was devised by the German psychologist William Stern in 1912 as a proposed method of scoring children’s intelligence tests such as those developed by Alfred Binet and Théodore Simon in the early 20th Century⁠[1]. Lewis Terman accepted that form of scoring, expressing a score as a quotient of “mental age” and “chronological age,” for his revision of the Binet-Simon test,⁠[1] the first version of the Stanford-Binet Intelligence Scales.Although the term “IQ” is still in common use, the scoring of modern IQ tests such as the Wechsler Adult Intelligence Scale is now based on standard scoring of the subject’s rank order on the test item content with the median score set to 100, and a standard deviation of 15, although not all tests adhere to that assignment of 15 IQ points to each standard deviation. IQ scores have been shown to be associated with such factors as morbidity and mortality, parental social status,⁠[2] and, to a substantial degree, parental IQ. While the heritability of IQ has been investigated for nearly a century, controversy remains regarding the significance of heritability estimates,⁠[3][4] and the mechanisms of inheritance are still a matter of some debate[5]. IQ scores are used in many contexts: as predictors of educational achievement or special needs, by social scientists who study the distribution of IQ scores in populations and the relationships between IQ score and other variables, and as predictors of job performance and income. The average IQ scores for many populations have been rising at an average rate of three points per decade since the early 20th century, a phenomenon called the Flynn effect. It is disputed whether these changes in scores reflect real changes in intellectual abilities, or merely methodological problems with past or present testing. Key takeaways IQ scores summarize performance on standardized tests intended to assess aspects of intelligence. Scores are used in educational and occupational contexts and are influenced by interacting developmental, environmental, and genetic factors. Interpretation remains subject to debate about measurement, bias, and how fully tests capture human intellectual ability. History Psychometrics Englishman Francis Galton, influenced by Darwinism, founded eugenics (and later psychometrics) to measure differences between upper and lower classes⁠[6]. Galton argued that due to heredity, white aristocrats were intellectually superior to other humans; nurture, meanwhile, played a lesser role in intellectual capacity⁠[7]. Clinical diagnostics French psychologist Alfred Binet gave more weight to nurture, arguing that intelligence could be improved⁠[8]. Binet and fellow French psychologist Théodore Simon later developed the Binet-Simon test for measuring intellectual development or mental age to diagnose French children in need of special assistance classes⁠[9]. Binet-Simon tasks were diverse in order to neutralize individual differences in types of intelligence and provide a general measure. Subject matter expert Roy Sugarman, Ph.D. Neuroscience and clinical mental health View profile Intelligence testing English psychologist Charles Spearman, however, did not believe there were different types of intelligence⁠[10]. He devised a correlational formula to define a common intellective factor (which he called “general intelligence”), a factor that Binet argued did not exist⁠[11]. Intelligence quotient (IQ) In 1910 the eugenics movement in the USA seized on the Binet-Simon test as means to give them credibility in diagnosing mental retardation after American psychologist Henry H. Goddard published a translation of it that same year⁠[12]. American psychologist Lewis Terman revised the Binet-Simon scale, implementing German psychologist William Stern‘s intelligence quotient (I.Q.) ratio of mental age to chronological age and used the resulting Stanford-Binet scale as a measure of general intelligence⁠[13]. World War I: large scale testing A team of psychologists led by eugenicist Robert Yerkes assisted the US army to rapidly assess and assign huge numbers of personnel⁠[14]. They developed two group-administered intelligence tests for this purpose: an alpha test for literate personnel; and a beta for the illiterate. They successfully tested 1,726,000 recruits⁠[15]. However, there was too little time for validity testing⁠[16] and not enough staff to administer tests correctly⁠[17]. Many officers distrusted the psychologists, accusing them of conducting research for their own purposes⁠[17] using culturally biased tests⁠[18]. Orders were issued that low test scores should not bar men from officer training and that a disability board should consider all discharges⁠[19]. The outcome was that 0.5% of recruits were discharged as mentally inferior, whilst Yerkes would have preferred to have discharged 3% whose results showed a mental age of under 10⁠[15]. In contrast, another team of psychologists led by Walter Dill Scott defined intelligence as a diverse complex of capacities, as Binet had. They stressed an individual differences approach emphasizing environmental adjustments of mental qualities as functions⁠[11]. Soon they developed a rating scale to classify and place enlisted men according to how they used their intelligence, not their base levels of intelligence⁠[18]. The army was enthusiastic about Scott’s classification of personnel. By the time the war ended they had already been incorporated into the military⁠[17] and had classified 3½ million men and assigned 973,858 to technical units⁠[15]. Post war to 1929 The army abolished Yerkes’ team after the war but employed two psychologists to continue intelligence testing research⁠[17]. However, a great deal of positive post war publicity on army psychological testing helped to make psychology a respected field⁠[20]. Subsequently there was an increase in jobs and funding in psychology⁠[21]. Group intelligence tests were developed for and became widely used in both primary and secondary schools, universities and industry⁠[17]. But controversy followed when one of Yerkes’ team, Goddard, admitted that they had been guilty of bad logic in finding that 45% of army recruits had a mental age of 12 or less⁠[22]. In addition, there was no agreement on what the intelligence tests measured,⁠[23][24][25] and the publication of racial differences in scores⁠[26] led to much criticism that environmental influences on score had not been considered⁠[23][27]. Wechsler’s innovation in scoring Modern IQ scores compare performance with a reference group. The average is usually set at 100, with a standard deviation of 15[28]. The modern IQ scale is a mathematical transformation of a raw score on an IQ test, based on the rank of that score in a normalization sample. This procedure was pioneered by David Wechsler. Modern scores are sometimes referred to as “deviation IQs,” while older method age-specific scores are referred to as “ratio IQs.”⁠[29] IQ scales of either kind are ordinal scales and thus IQ points are not units of measurement⁠[30][31][32][33]. The two scoring methodologies yield similar results near the population median, but the older ratio IQs yielded far higher scores for high-scoring (gifted) children. Current IQ tests do not yield such high scores, as recent validation studies have shown that concerns about ceiling effects in identifying gifted children are exaggerated⁠[34]. In any event error of estimation is greatest for scores above the population median⁠[35] and likely to overestimate the true score (in the sense of formal testing theory) of a test-taker who obtains a score above the median⁠[36]. Since the publication of the Wechsler Adult Intelligence Scale (WAIS), almost all intelligence scales have adopted the deviation method of scoring. The use of this scoring method makes the term “intelligence quotient” an inaccurate description, mathematically speaking, but the term “IQ” still enjoys colloquial usage,⁠[37] and is used to label the standard scoring of most cognitive ability tests currently in use. Reliability Psychometricians generally regard IQ tests as highly reliable (in the technical sense of testing theory) and clinical psychologists generally regard them as having sufficient validity for many clinical purposes. A test-taker's score on any one IQ test is surrounded by an error band that shows, to a specified degree of confidence, what the test-taker's true score (in that same technical sense) is likely to be. Test-takers can have varying scores on differing occasions of taking IQ tests and can vary in scores on different IQ tests taken at the same age⁠[39][40][41]. The General Intelligence Factor (g) Main article: General intelligence factor There are many different kinds of IQ tests using a wide variety of methods. Some tests are visual, some are verbal, some tests only use of abstract-reasoning problems, and some tests concentrate on arithmetic, spatial imagery, reading, vocabulary, memory or general knowledge⁠[42]. The psychologist Charles Spearman early this century made the first formal factor analysis of correlations between the tests. He found that a single common factor explained for the positive correlations among tests. This is an argument still accepted in principle by many psychometricians. Spearman named it g for \"general intelligence factor.\" In any collections of IQ tests, by definition the test that best measures g is the one that has the highest correlations with all the others. Most of these g-loaded tests typically involve some form of abstract reasoning. Therefore Spearman and others have regarded g as the perhaps genetically determined real essence of intelligence. This is still a common but not proven view. Other factor analyses of the data with different results are possible. Some psychometricians regard g as a statistical artifact. The accepted best measure of g is Raven's Progressive Matrices which is a test of visual reasoning⁠[42]. Trends in IQ Main article: Flynn effect Since the early twentieth century, raw scores on IQ tests have increased in most parts of the world⁠[43][44][45]. When a new version of an IQ test is normed, the standard scoring is set so that performance at the population median results in a score of IQ 100. The phenomenon of rising raw score performance means that if test-takers are scored by a constant standard scoring rule, IQ test scores have been rising at an average rate of around three IQ points per decade. This phenomenon was named the Flynn effect in the book The Bell Curve after James R. Flynn, the author who did the most to bring this phenomenon to the attention of psychologists⁠[46][47]. Researchers have been exploring the issue of whether the Flynn effect is equally strong on performance of all kinds of IQ test items, whether the effect may have ended in some developed nations, whether or not there are social subgroup differences in the effect, and what possible causes of the effect might be⁠[48]. Flynn's observation has prompted much new research in psychology and \"demolish some long-cherished beliefs, and raise a number of other interesting issues along the way.\"⁠[44] Environmental and genetic influences and malleability Environmental influences See also: Health and intelligence and environment and intelligence Environmental factors play a role in determining IQ. Proper childhood nutrition appears critical for cognitive development; malnutrition can lower IQ. For example, iodine deficiency causes a fall, in average, of 12 IQ points⁠[49]. It is expected that average IQ in third world countries will increase dramatically if the deficiencies of iodine and other micronutrients are eradicated. A recent study found that the FADS2 gene, along with breastfeeding, adds about seven IQ points to those with the \"C\" version of the gene. Those with the \"G\" version of the FADS2 gene see no advantage⁠[50][51]. Musical training in childhood may also increase IQ⁠[52]. Recent studies have shown that training in using one's working memory may increase IQ⁠[53][54]. Family environment Some studies in the developed world have shown that inherited personality traits cause non-related children raised in the same family (\"adoptive siblings\") to be as different as children raised in different families⁠[55].[not in citation given][56] There are some family effects on the IQ of children, accounting for up to a quarter of the variance; however, by adulthood, this correlation approaches zero⁠[57]. For IQ, adoption studies show that, after adolescence, adoptive siblings are no more similar in IQ than strangers (IQ correlation near zero), while full siblings show an IQ correlation of 0.6. Twin studies reinforce this pattern: monozygotic (identical) twins raised separately are highly similar in IQ (0.86), more so than dizygotic (fraternal) twins raised together (0.6) and much more than adoptive siblings⁠[55].[not in citation given] However these results make no correction for the social and emotional effects frequently associated with adoption. Possible bias in older studies Stoolmiller (1999)⁠[58] found that the range restriction of family environments that goes with adoption, that adopting families tend to be more similar on, for example, socio-economic status than the general population, suggests a possible underestimation of the role of the shared family environment in previous studies. Corrections for range correction applied to adoption studies indicate that socio-economic status could account for as much as 50% of the variance in IQ⁠[58]. However, the effect of restriction of range on IQ for adoption studies was examined by Matt McGue and colleagues, who wrote that \"restriction in range in parent disinhibitory psychopathology and family socio-economic status had no effect on adoptive-sibling correlations [in] IQ\"⁠[59]. Eric Turkheimer and colleagues (2003)⁠[60] studied the \"Massive IQ Gains in 14 Nations: What IQ Tests Really Measure\" heritability of IQ in impoverished US families. Results demonstrated that in small children the proportions of IQ variance attributable to genes and environment vary nonlinearly with socio-economic status. In a 2003 study of young U.S. twins, estimated genetic and shared-environment contributions varied with family socioeconomic status. These estimates describe that study population and do not determine an individual’s abilities[60]. Maternal (fetal) environment A meta-analysis, by Devlin and colleagues in Nature (1997),⁠[5] of 212 previous studies evaluated an alternative model for environmental influence and found that it fits the data better than the 'family-environments' model commonly used. The shared maternal (fetal) environment effects, often assumed to be negligible, account for 20% of covariance between twins and 5% between siblings, and the effects of genes are correspondingly reduced, with two measures of heritability being less than 50%. Bouchard and McGue reviewed the literature in 2003, arguing that Devlin's conclusions about the magnitude of heritability is not substantially different from previous reports and that their conclusions regarding prenatal effects stands in contradiction to many previous reports⁠[63]. They write that: Chipuer et al. and Loehlin conclude that the postnatal rather than the prenatal environment is most important. The Devlin et al. conclusion that the prenatal environment contributes to twin IQ similarity is especially remarkable given the existence of an extensive empirical literature on prenatal effects. Price (1950), in a comprehensive review published over 50 years ago, argued that almost all MZ twin prenatal effects produced differences rather than similarities. As of 1950 the literature on the topic was so large that the entire bibliography was not published. It was finally published in 1978 with an additional 260 references. At that time Price reiterated his earlier conclusion. Research subsequent to the 1978 review largely reinforces Price's hypothesis. Dickens and Flynn model Dickens and Flynn⁠[64] postulate that the arguments regarding the disappearance of the shared family environment should apply equally well to groups separated in time. This is contradicted by the Flynn effect. Changes here have happened too quickly to be explained by genetic heritable adaptation. This paradox can be explained by observing that the measure \"heritability\" includes both a direct effect of the genotype on IQ and also indirect effects where the genotype changes the environment, in turn affecting IQ. That is, those with a higher IQ tend to seek out stimulating environments that further increase IQ. The direct effect can initially have been very small but feedback loops can create large differences in IQ. In their model an environmental stimulus can have a very large effect on IQ, even in adults, but this effect also decays over time unless the stimulus continues (the model could be adapted to include possible factors, like nutrition in early childhood, that may cause permanent effects). The Flynn effect can be explained by a generally more stimulating environment for all people. The authors suggest that programs aiming to increase IQ would be most likely to produce long-term IQ gains if they taught children how to replicate outside the program the kinds of cognitively demanding experiences that produce IQ gains while they are in the program and motivate them to persist in that replication long after they have left the program⁠[64][65]. Genetic influences Main article: Heritability of IQ Various studies find the heritability of IQ between 0.4 and 0.8 in the United States;⁠[66][67][68] that is, depending on the study, a little less than half to substantially more than half of the variation in IQ among the children studied was estimated to be due to genetic variation. Heritability measures the proportion of variation that can be attributed to genes within any measured population (however defined), and not the extent that genes contribute to intelligence. It should also be noted that the idea that genetic and environmental influences on intelligence are independent is not necessarily accepted, or as Jeremy Freese says \"The lucidity of Lewontin's arguments has historically proven no match for the allure of overly simple characterizations of outcomes as being x% due to genes and (1 – x)% not due to genes\". That means that genes affect environment and environment affects genes⁠[69][70][71][72][73][74]. A heritability in the range of 0.4 to 0.8 implies that IQ is \"substantially\" heritable, that is, some substantial part of the variation within a population is caused at least in part by genes. The effect of restriction of range on IQ was examined by Matt McGue and colleagues, who wrote that \"restriction in range in parent disinhibitory psychopathology and family SES had no effect on adoptive-sibling correlations ... IQ.\"⁠[59] On the other hand, a 2003 study by Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. Gottesman demonstrated that the proportions of IQ variance attributable to genes and environment vary with socioeconomic status. They found that in impoverished families, 60% of the variance in IQ \"in a sample of 7-year-old twins\" is accounted for by the shared environment, and the contribution of genes was close to zero⁠[75]. It is reasonable to expect that genetic influences on traits like IQ should become less important as one gains experiences with age. However, the opposite occurs⁠[76]. Heritability measures in infancy are as low as 20%, around 40% in middle childhood, and as high as 80% in adulthood⁠[76]. The American Psychological Association's 1995 task force on \"Intelligence: Knowns and Unknowns\" concluded that within the white population the heritability of IQ is \"around .75.\" The Minnesota Study of Twins Reared Apart, a multiyear study of 100 sets of reared-apart twins which was started in 1979, concluded that about 70% of the variance in IQ was found to be associated with genetic variation. Some of the correlation of IQs of twins may be a result of the effect of the maternal environment before birth, shedding some light on why IQ correlation between twins reared apart is so robust⁠[5]. There are a number of points to consider when interpreting heritability: A high heritability does not mean that the environment has no effect on the development of a trait, or that learning is not involved. Vocabulary size, for example, is very substantially heritable (and highly correlated with general intelligence) although every word in an individual's vocabulary is learned. In a society in which plenty of words are available in everyone's environment, especially for individuals who are motivated to seek them out, the number of words that individuals actually learn depends to a considerable extent on their genetic predispositions⁠[67]. A common error is to assume that because something is heritable it is necessarily unchangeable. As previously noted, heritable traits can depend on learning, and they may be subject to other environmental effects as well. The value of heritability can change if the distribution of environments (or of genes) in the population is substantially altered. For example, an impoverished or suppressive environment could fail to support the development of a trait, and hence restrict individual variation. Differences in variation of heritability are found between developed and developing nations. This could affect estimates of heritability⁠[67]. Another example is Phenylketonuria which previously caused mental retardation for everyone who had this genetic disorder. Today, this can be prevented by following a modified diet. On the other hand, there can be effective environmental changes that do not change heritability at all. If the environment relevant to a given trait improves in a way that affects all members of the population equally, the mean value of the trait will rise without any change in its heritability (because the differences among individuals in the population will stay the same). This has evidently happened for height: the heritability of stature is high, but average heights continue to increase⁠[67]. Even in developed nations, high heritability of a trait within a given group has no necessary implications for the source of a difference between groups⁠[67][77]. IQ and the brain Main article: Neuroscience and intelligence In 2004, Richard Haier, professor of psychology in the Department of Pediatrics and colleagues at University of California, Irvine and the University of New Mexico used MRI to obtain structural images of the brain in 47 normal adults who also took standard IQ tests. The study demonstrated that general human intelligence appears to be based on the volume and location of gray matter tissue in the brain, and also demonstrated that, of the brain's gray matter, only about 6 percent appeared to be related to IQ⁠[78].[non-primary source needed] A large lesion study examined 227 people with focal brain damage and 165 healthy controls using Raven’s Advanced Progressive Matrices. Participants with frontal lesions, particularly on the right, performed worse; participants with non-frontal lesions did not differ from controls. This supports the importance of right frontal regions for performance on this fluid-reasoning task, without reducing all forms of intelligence to a single brain area⁠[79]. A study involving 307 children (aged from six to nineteen) measuring the size of brain structures using magnetic resonance imaging (MRI) and measuring verbal and non-verbal abilities has been conducted (Shaw et al. 2006)⁠[80].[non-primary source needed] This study indicated that higher intelligence is not directly related to cortical thickness, but rather the change in cortical thickness over time. A study of cortical development found that the relationship between cortical thickness and intelligence changed with age[80]. There is \"a highly significant association\" between the CHRM2 gene and intelligence according to a 2006 Dutch family study. The study concluded that there was an association between the CHRM2 gene on chromosome 7 and Performance IQ, as measured by the Wechsler Adult Intelligence Scale-Revised. The Dutch family study used a sample of 667 individuals from 304 families⁠[83].[non-primary source needed] A similar association was found independently in the Minnesota Twin and Family Study (Comings et al. 2003) and by the Department of Psychiatry at the Washington University⁠[84].[non-primary source needed] Significant injuries isolated to one side of the brain, especially those occurring at a young age, may not significantly affect IQ⁠[85]. Studies reach conflicting conclusions regarding the controversial idea that brain size correlates positively with IQ. Jensen and Reed claim no direct correlation exists in nonpathological subjects⁠[86]. A more recent meta-analysis suggests otherwise⁠[87]. Malleability (mutability or changeability) Although IQ is believed by many to be immutable,⁠[88] recent research suggests that certain mental activities can change the brain's ability to process information, leading to the conclusion that intelligence can be altered or changed over time. The brain is now properly understood to be neuroplastic and hence far more amenable to change than once was thought. Studies into the neuroscience of animals indicate that challenging activities can produce changes in gene expression patterns of the brain. (Training Degus to Use Rakes⁠[89] and Iriki's earlier research with macaque monkeys indicating brain changes.) A study on young adults published in April 2008 by a team from the Universities of Michigan and Bern supports the possibility of the transfer of fluid intelligence from specifically designed working memory training[90]. Further research will be needed to determine nature, extent and duration of the proposed transfer:⁠[91] Among other questions, it remains to be seen whether the results extend to other kinds of fluid intelligence tests than the matrix test used in the study, and if so, whether, after training, fluid intelligence measures retain their correlation with educational and occupational achievement or if the value of fluid intelligence for predicting performance on other tasks changes. It is also unclear whether the training is durable of extended periods of time. The peak capacity for both fluid intelligence and crystallized intelligence is 26 years. This is followed by a slow decline⁠[92]. Validity and social significance While IQ is sometimes treated as an end unto itself, scholarly work on IQ focuses to a large extent on IQ's validity, that is, the degree to which IQ correlates with outcomes such as job performance, social pathologies, or academic achievement. Different IQ tests differ in their validity for various outcomes.[citation needed] Traditionally, correlation for IQ and outcomes is viewed as a means to also predict performance; however readers should distinguish between prediction in the hard sciences and the social sciences. Health Main article: Health and intelligence People with a higher IQ have generally lower adult morbidity and mortality. Post-Traumatic Stress Disorder,⁠[93] and schizophrenia[94][95] are less prevalent in higher IQ bands. People in the midsts of a major depressive episode have been shown to have a lower IQ than when without symptoms and lower cognitive ability than people without depression of equivalent verbal intelligence⁠[96][97]. A study of 11,282 individuals in Scotland who took intelligence tests at ages 7, 9 and 11 in the 1950s and 1960s, found an \"inverse linear association\" between childhood IQ scores and hospital admissions for injuries in adulthood. The association between childhood IQ and the risk of later injury remained even after accounting for factors such as the child's socioeconomic background⁠[98]. Research in Scotland has also shown that a 15-point lower IQ meant people had a fifth less chance of living to 76, while those with a 30-point disadvantage were 37% less likely than those with a higher IQ to live that long⁠[99]. A decrease in IQ has also been shown as an early predictor of late-onset Alzheimer's Disease and other forms of dementia. In a 2004 study, Cervilla and colleagues showed that tests of cognitive ability provide useful predictive information up to a decade before the onset of dementia⁠[100]. However, when diagnosing individuals with a higher level of cognitive ability, in this study those with IQs of 120 or more,⁠[101] patients should not be diagnosed from the standard norm but from an adjusted high-IQ norm that measured changes against the individual's higher ability level. In 2000, Whalley and colleagues published a paper in the journal Neurology, which examined links between childhood mental ability and late-onset dementia. The study showed that mental ability scores were significantly lower in children who eventually developed late-onset dementia when compared with other children tested⁠[102]. Several factors can lead to significant cognitive impairment, particularly if they occur during pregnancy and childhood when the brain is growing and the blood-brain barrier is less effective. Such impairment may sometimes be permanent, or may sometimes be partially or wholly compensated for by later growth. Several harmful factors may also combine, possibly causing greater impairment. Preventing toxic exposures is one way to protect cognitive development. WHO identifies lead as especially harmful to children: exposure can affect brain development, attention, learning, and IQ, even without obvious early symptoms. There is no known safe blood lead concentration, so reducing exposure is a public-health priority⁠[103]. In terms of the effect of one's intelligence on health, in one British study, high childhood IQ was shown to correlate with one's chance of becoming a vegetarian in adulthood⁠[104]. In another British study, high childhood IQ was shown to inversely correlate with the chances of smoking⁠[105]. Other tests Intelligence-test scores and educational experience are related. A meta-analysis of quasi-experimental studies also found evidence that additional schooling can improve cognitive-test performance, so the relationship should not be interpreted solely as intelligence determining educational success⁠[107]. Ritchie and Tucker-Drob combined 42 datasets involving more than 600,000 participants. Across the designs studied, an additional year of education was associated with an estimated one to five IQ points of improvement. This is a study-level estimate, not a guaranteed change for any individual⁠[107]. School performance The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that wherever it has been studied, children with high scores on tests of intelligence tend to learn more of what is taught in school than their lower-scoring peers. The correlation between IQ scores and grades is about .50. However, this means that they explain only 25% of the variance. Achieving good grades depends on many factors other than IQ, such as \"persistence, interest in school, and willingness to study\" (p. 81). Job performance According to Frank Schmidt and John Hunter, \"for hiring employees without previous experience in the job the most valid predictor of future performance is general mental ability.\"⁠[108] The validity of IQ as a predictor of job performance is above zero for all work studied to date, but varies with the type of job and across different studies, ranging from 0.2 to 0.6⁠[109]. While IQ is more strongly correlated with reasoning and less so with motor function⁠[110] IQ-test scores predict performance ratings in all occupations⁠[108]. That said, for highly qualified activities (research, management) low IQ scores are more likely to be a barrier to adequate performance, whereas for minimally-skilled activities, athletic strength (manual strength, speed, stamina, and coordination) are more likely to influence performance⁠[108]. It is largely mediated through the quicker acquisition of job-relevant knowledge that IQ predicts job performance. In establishing a causal direction to the link between IQ and work performance, longitudinal studies by Watkins and others suggest that IQ exerts a causal influence on future academic achievement, whereas academic achievement does not substantially influence future IQ scores⁠[111]. Treena Eileen Rohde and Lee Anne Thompson write that general cognitive ability but not specific ability scores predict academic achievement, with the exception that processing speed and spatial ability predict performance on the SAT math beyond the effect of general cognitive ability⁠[112]. The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that other individual characteristics such as interpersonal skills, aspects of personality etc. are probably of equal or greater importance, but at this point we do not have equally reliable instruments to measure them⁠[67]. More recently, others argue that since most professional tasks are now standardized or automated, and ranked IQ is a stable measurement over time with high correlation with many positive personal traits from the general population, it is the best tool to help determine hiring and job placement at any stage in a career, independently of experience, personality bias or any formal training one may acquire.[citation needed] Income Some researchers claim that \"in economic terms it appears that the IQ score measures something with decreasing marginal value. It is important to have enough of it, but having lots and lots does not buy you that much.\"⁠[113][114] Other studies show that ability and performance for jobs are linearly related, such that at all IQ levels, an increase in IQ translates into a concomitant increase in performance⁠[115]. Charles Murray, coauthor of The Bell Curve, found that IQ has a substantial effect on income independently of family background⁠[116]. Taking the above two principles together, very high IQ produces very high job performance, but no greater income than slightly high IQ. Studies also show that high IQ is related to higher net worth⁠[117]. The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that IQ scores account for about one-fourth of the social status variance and one-sixth of the income variance. Statistical controls for parental SES eliminate about a quarter of this predictive power. Psychometric intelligence appears as only one of a great many factors that influence social outcomes⁠[67]. Some studies claim that IQ only accounts for a sixth of the variation in income because many studies are based on young adults (many of whom have not yet completed their education). On pg 568 of The g Factor, Arthur Jensen claims that although the correlation between IQ and income averages a moderate 0.4 (one sixth or 16% of the variance), the relationship increases with age, and peaks at middle age when people have reached their maximum career potential. In the book, A Question of Intelligence, Daniel Seligman cites an IQ income correlation of 0.5 (25% of the variance). A 2002 study⁠[118] further examined the impact of non-IQ factors on income and concluded that an individual's location, inherited wealth, race, and schooling are more important as factors in determining income than IQ. Other correlations with IQ In addition, IQ and its correlation to health, violent crime, gross state product, and government effectiveness are the subject of a 2006 paper in the publication Intelligence. The paper breaks down IQ averages by U.S. states using the federal government's National Assessment of Educational Progress math and reading test scores as a source⁠[119]. There is a correlation of -0.19 between IQ scores and number of juvenile offences in a large Danish sample; with social class controlled, the correlation dropped to -0.17. Similarly, the correlations for most \"negative outcome\" variables are typically smaller than 0.20, which means that test scores are associated with less than 4% of their total variance. It is important to realize that the causal links between psychometric ability and social outcomes may be indirect. Children with poor scholastic performance may feel alienated. Consequently, they may be more likely to engage in delinquent behavior, compared to other children who do well⁠[67]. IQ is also negatively correlated with certain diseases. Tambs et al.[120] found that occupational status, educational attainment, and IQ are individually heritable; and further found that \"genetic variance influencing educational attainment ... contributed approximately one-fourth of the genetic variance for occupational status and nearly half the genetic variance for IQ.\" In a sample of U.S. siblings, Rowe et al.[121] report that the inequality in education and income was predominantly due to genes, with shared environmental factors playing a subordinate role. A 2022 meta-analysis covering 89 studies and 201,457 participants found a small negative association between intelligence measures and religiosity. Its strength varied with measurement choices and the populations studied. This group-level correlation does not establish that religious identity causes differences in intelligence or determine any individual’s ability⁠[122]. Group differences Among the most controversial issues related to the study of intelligence is the observation that intelligence measures such as IQ scores vary between ethnic and racial groups and sexes. While there is little scholarly debate about the existence of some of these differences, their causes remain highly controversial both within academia and in the public sphere. Sex Main article: Sex and intelligence Men and women have statistically significant differences in average scores on tests of particular abilities⁠[123][124]. Studies also illustrate consistently greater variance in the performance of men compared to that of women⁠[125]. Interpreting comparisons between groups requires attention to what a test measures and the circumstances in which it is taken. Noba’s overview describes multiple possible influences on intellectual-test performance, including social expectations, learning opportunities, and test-taking strategies. A difference in a selected sample does not establish a simple, universal ranking of men’s and women’s intelligence⁠[126]. Race Main articles: History of the race and intelligence controversy and Race and intelligence The 1996 Task Force investigation on Intelligence sponsored by the American Psychological Association concluded that there are significant variations in I.Q. across races⁠[67]. The problem of determining the causes underlying this variation relates to the question of the contributions of \"nature and nurture\" to I.Q. Psychologists such as Alan S. Kaufman[128] and Nathan Brody⁠[129] and statisticians such as Bernie Devlin⁠[130] point out there are insufficient data to conclude that this is because of genetic influences. One of the most notable authors arguing for a strong genetic influence on this score difference is Arthur Jensen. In contrast, Richard Nisbett, the long-time director of the Culture and Cognition program at the University of Michigan, argues that environmental influences are not sufficiently taken into account in Jensen's writings⁠[131]. Age For decades, it has been reported in practitioners' handbooks and textbooks on IQ testing that IQ declines with age after the beginning of adulthood. However, later researchers pointed out that this phenomenon is related to the Flynn effect and is in part a cohort effect rather than a true aging effect. There have been a variety of studies of IQ and aging since the norming of the first Wechsler Intelligence Scale drew attention to IQ differences in different age groups of adults. Current consensus is that fluid intelligence generally declines with age after early adulthood, while crystallized intelligence remains intact. Both cohort effects (the birth year of the test-takers) and practice effects (test-takers taking the same form of IQ test more than once) must be controlled for to gain accurate data. It is unclear whether any lifestyle intervention can preserve fluid intelligence into older ages⁠[132]. Public policy The examples and perspective in this article deal primarily with USA and do not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (August 2010) Main article: Intelligence and public policy In the United States, certain public policies and laws regarding military service,⁠[133][134] education, public benefits,⁠[135] capital punishment,⁠[189] and employment incorporate an individual's IQ into their decisions. However, in the case of Griggs v. Duke Power Co. in 1971, for the purpose of minimizing employment practices that disparately impacted racial minorities, the U.S. Supreme Court banned the use of IQ tests in employment, except in very rare cases⁠[137]. Internationally, certain public policies, such as improving nutrition and prohibiting neurotoxins, have as one of their goals raising, or preventing a decline in, intelligence. Criticism and views Binet Alfred Binet, a French psychologist, did not believe that IQ test scales qualified to measure intelligence. He neither invented the term \"intelligence quotient\" nor supported its numerical expression.[citation needed] He stated: The scale, properly speaking, does not permit the measure of intelligence, because intellectual qualities are not superposable, and therefore cannot be measured as linear surfaces are measured. —Binet, 1905 Binet had designed the Binet-Simon intelligence scale in order to identify students who needed special help in coping with the school curriculum. He argued that with proper remedial education programs, most students regardless of background could catch up and perform quite well in school. He did not believe that intelligence was a measurable fixed entity. The Mismeasure of Man Some scientists dispute psychometrics entirely. In The Mismeasure of Man, Harvard professor and paleontologist Stephen Jay Gould argued that intelligence tests were based on faulty assumptions and showed their history of being used as the basis for scientific racism. He criticized …the abstraction of intelligence as a single entity, its location within the brain, its quantification as one number for each individual, and the use of these numbers to rank people in a single series of worthiness, invariably to find that oppressed and disadvantaged groups—races, classes, or sexes—are innately inferior and deserve their status.(pp. 24–25) He spends much of the book criticizing the concept of IQ, including a historical discussion of how the IQ tests were created and a technical discussion of why g is simply a mathematical artifact. Later editions of the book included criticism of The Bell Curve. Bernard Davis wrote that while the nonscientific reviews of The Mismeasure of Man were almost uniformly laudatory, the reviews in the scientific journals were almost all highly critical⁠[139]. Peter H. Schönemann Psychologist Peter Schönemann has been a persistent critic of IQ, calling it \"the IQ myth\"⁠[140]. He argued that Spearman's g is a flawed theory and the high heritability estimates of IQ are based on false assumptions⁠[141]. [editEric Turkheimer ] Relation between IQ and intelligence See also: Intelligence According to Dr. C. George Boeree of Shippensburg University, intelligence is a person's capacity to (1) acquire knowledge (i.e. learn and understand), (2) apply knowledge (solve problems), and (3) engage in abstract reasoning. It is the power of one's intellect, and as such is clearly a very important aspect of one's overall well-being. Psychologists have attempted to measure it for well over a century.[citation needed] IQ is associated with intelligence, but may fail to act as an accurate measure of \"intelligence\" in its broadest sense. This is partly because IQ tests only examine particular areas embodied by the broadest notion of \"intelligence\", failing to account for certain areas which are also associated with \"intelligence\" such as creativity or emotional intelligence.[citation needed] Several other ways of measuring intelligence have been proposed. Daniel Schacter, Daniel Gilbert, and others have moved beyond general intelligence and IQ as the sole means to describe intelligence⁠[142]. Test bias See also: Stereotype threat The American Psychological Association's report Intelligence: Knowns and Unknowns[67] states that IQ tests as predictors of social achievement are not biased against people of African descent since they predict future performance, such as school achievement, similarly to the way they predict future performance for people of European descent⁠[67]. However, IQ tests may well be biased when used in other situations. A 2005 study stated that \"differential validity in prediction suggests that the WAIS-R test may contain cultural influences that reduce the validity of the WAIS-R as a measure of cognitive ability for Mexican American students,\"⁠[143] indicating a weaker positive correlation relative to sampled white students. Other recent studies have questioned the culture-fairness of IQ tests when used in South Africa⁠[144][145]. Standard intelligence tests, such as the Stanford-Binet, are often inappropriate for children with autism; the alternative of using developmental or adaptive skills measures are relatively poor measures of intelligence in autistic children, and may have resulted in incorrect claims that a majority of children with autism are mentally retarded⁠[146]. Outdated methodology Modern test evaluation requires evidence that supports the intended interpretation and use of scores. The joint Standards for Educational and Psychological Testing emphasize validity, reliability or measurement precision, and fairness; evidence for one purpose does not automatically justify a different use⁠[147]. The view of the American Psychological Association In response to the controversy surrounding The Bell Curve, the American Psychological Association's Board of Scientific Affairs established a task force in 1995 to write a report on the state of intelligence research which could be used by all sides as a basis for discussion. The full text of the report is available through several websites⁠[67][148]. In this paper the representatives of the association regret that IQ-related works are frequently written with a view to their political consequences: \"research findings were often assessed not so much on their merits or their scientific standing as on their supposed political implications\". The task force concluded that IQ scores do have high predictive validity for individual differences in school achievement. They confirm the predictive validity of IQ for adult occupational status, even when variables such as education and family background have been statistically controlled. They found that individual differences in intelligence are substantially influenced by genetics and that both genes and environment, in complex interplay, are essential to the development of intellectual competence. The report stated that a number of biological factors, including malnutrition, exposure to toxic substances, and various prenatal and perinatal stressors, result in lowered psychometric intelligence under at least some conditions. The task force agrees that large differences do exist between the average IQ scores of blacks and whites, and that these differences cannot be attributed to biases in test construction. The task force suggests that explanations based on social status and cultural differences are possible, and that environmental factors have raised mean test scores in many populations. Regarding genetic causes, they noted that there is not much direct evidence on this point, but what little there is fails to support the genetic hypothesis. The APA journal that published the statement, American Psychologist, subsequently published eleven critical responses in January 1997, several of them arguing that the report failed to examine adequately the evidence for partly-genetic explanations. High IQ societies Main article: High IQ society There are social organizations, some international, which limit membership to people who have scores as high as or higher than the 98th percentile on some IQ test or equivalent. Mensa International is perhaps the most well known of these. There are other groups requiring a score above the 98th percentile. Popular culture usage Many websites and magazines use the term IQ to refer to technical or popular knowledge in a variety of subjects not related to intelligence, including sex,⁠[149] poker,⁠[150] and American football,⁠[151] among a wide variety of other topics. These tests are generally not standardized and do not fit within the normal definition of intelligence. Intelligence tests such as the Wechsler Adult Intelligence Scale, Wechsler Intelligence Scale for Children, Stanford-Binet, Woodcock-Johnson III Tests of Cognitive Abilities, or the Kaufman Assessment Battery for Children-II, to name some of the best constructed, are not merely placing a test taker's score within the norm, as presumably are the thousands of alleged \"IQ Tests\" found on the internet, but they are also testing factors (e.g., fluid and crystallized intelligence, working memory, and the like) that were previously found to represent pure measures of intelligence using factor analysis. This claim may not be made for the hundreds of online tests marketing themselves as IQ Tests, a distinction that may be unfortunately lost upon the public taking them. Reference charts Main article: IQ reference chart IQ reference charts are tables suggested by test publishers to divide intelligence ranges in various categories. See also Child prodigy Cultural intelligence Curiosity quotient CHC Theory Developmental disability Educational quotient Emotional intelligence Genius Heritability of IQ Intellectual giftedness Intelligence: Knowns and Unknowns IQ reference chart IQ testing environmental variances Late bloomer Learning disability Mental retardation Nature versus nurture Savant syndrome Sentience quotient Social IQ Spiritual intelligence Theory of multiple intelligences Triarchic theory of intelligence Wechsler Intelligence Scale for Children (WISC) Woodcock-Johnson Tests of Cognitive Abilities References Notes References Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. p. 15. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive. Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report. Johnson, W., Turkheimer, E., Gottesman, I. I., & Bouchard, T. J., Jr. (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18(4), 217–220. doi: 10.1111/j.1467-8721.2009.01639.x. PubMed Central. SAGE Journals. National Library of Medicine. Accessed October 10 2026. Turkheimer, E. (2008, Spring). A Better Way to Use Twins for Developmental Research. LIFE Newsletter, 2–5. Max Planck Institute for Human Development. University of Virginia. Accessed June 29 2010. Devlin, B., Daniels, M., & Roeder, K. (1997, July 31). The heritability of IQ. Nature, 388(6641), 468–471. doi: 10.1038/41319. PubMed. Accessed October 10 2026. Gillham, N. W. (2001). Sir Francis Galton and the birth of eugenics. Annual Review of Genetics, 35, 83-101. Galton, F. (1865). Hereditary talent and character. Classics in the history of psychology. psychclassics.yorku.ca. Accessed October 10 2026. Binet, A. (1916). New methods for the diagnosis of the intellectual level of subnormals. In The development of intelligence in children (E. S. Kite, Trans.). Publications of the Training School at Vineland. Original work published 1905. York University — Classics in the History of Psychology. Accessed July 10 2010. Wallin, J. E. W. (1911). The new clinical psychology and the psycho-clinicist. Journal of Educational Psychology, 2(4), 191-210. Spearman, C. (1904). General intelligence. objectively determined and measured. American Journal of Psychology, 15(2), 201-293. Mayrhauser, R. T. V. (1992). The mental testing community and validity: A prehistory. American Psychologist, 47(2), 244-253. Richardson, T. E. (2003). Howard Andrew Knox and the origins of performance testing on Ellis Island, 1212-1216. History of Psychology, 6(2), 143-170. Terman, L. M., Lyman, G., Ordahl, G., Ordahl, L., Galbreath, N., and Talbert, W. (1915). The Stanford revision of the Binet-Simon scale and some results from its application to 1000 non-selected children. The Journal of Educational Psychology, 6(9), 551-562. Carmichael, L. (1957). Robert Mearns Yerkes. The Psychological Review, 64(1), 1-7. Yerkes, R. (1919). Report of the psychology committee of the national research council. The Psychological Review, 26(2), 83-149. Driskell, J. E., & Olmstead, B. (1989). Psychology and the military: Research applications and trends. American Psychologist, 44(1), 43-54. Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581. Keene, J. D. (1994). Intelligence and morale in the army of a democracy: The genesis of military psychology during the First World War. Military Psychology, 6(4), 235-253. Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581. Kennedy, C. H., & McNeil, J. A. (2006). A history of military psychology. In C. H. Kennedy, E. A. Zillmer (Eds.), Military Psychology: Clinical and Operational Applications (pp.1-17). New York: Guilford Publications. Katzell, R. A., & Austin, J. T. (1992). From then to now: the development of industrial-organizational psychology in the United States. Journal of Applied Psychology. 77(6), 803-835. Goddard, H. H. (1921). The sub-normal mind versus the abnormal. Journal of Abnormal Psychology, 16(1), 47-54. Alper, T. G., & Boring, E. G. (1944). Intelligence-test scores of northern and southern white and negro recruits in 1918. Journal of Abnormal & Social Psychology, 39(4), 471-474. Thurstone, L. L. (1934). The vectors of mind. Psychological Review, 41, 1-32. Terman, L. M. (1924). The mental test as a psychological method. The Psychological Review, 31(2), 93-117. Garrett, H. E. (1945). A note on the intelligence scores of negroes and whites in 1918. Journal of Abnormal & Social Psychology, 40(3), 344-346. Rembis, M. A. (2004). I ain't been reading while on parole. Experts, mental tests, and eugenic commitment law in Illinois, 1890-1940. History of Psychology, 7(3), 225-247. IQ — APA Dictionary of Psychology. (n.d.). American Psychological Association. Pinneau, Samuel R. (1961). Changes in Intelligence Quotient Infancy to Maturity: New Insights from the Berkeley Growth Study with Implications for the Stanford-Binet Scales and Applications to Professional Practice. Boston: Houghton Mifflin. Mussen, Paul Henry. (1973). Psychology: An Introduction. Lexington (MA): Heath. p. 363. ISBN 0-669-61383-7. \"The I.Q. is essentially a rank; there are no true \"units\" of intellectual ability.\". en.wikipedia.org. en.wikipedia.org. Truch, Steve. (1993). The WISC-III Companion: A Guide to Interpretation and Educational Intervention. Austin (TX): Pro-Ed. p. 35. ISBN 0890795851. \"An IQ score is not an equal-interval score, as is evident in Table A.4 in the WISC-III manual.\". en.wikipedia.org. en.wikipedia.org. Bartholomew, D. J. (2004). Measuring Intelligence: Facts and Fallacies. Cambridge University Press, p. 50. ISBN 9780521544788. Cambridge University Press. Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. pp. 30–31. ISBN 0-19-852367-X. \"In the jargon of psychological measurement theory, IQ is an ordinal scale, where we are simply rank-ordering people. It is not even appropriate to claim that the 10-point difference between IQ scores of 110 and 100 is the same as the 10-point difference between IQs of 160 and 150\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Perleth, Christoph; Schatz, Tanja; Mönks, Franz J. (2000). Early Identification of High Ability. In Heller, Kurt A. Mönks, Franz J. Sternberg, Robert J. et al. International Handbook of Giftedness and Talent (2nd ed.). Amsterdam: Pergamon. p. 301. ISBN 978-0-08-043796-5. \"norm tables that provide you with such extreme values are constructed on the basis of random extrapolation and smoothing but not on the basis of empirical data of representative samples.\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Terman, Lewis Madison; Merrill, Maude A. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. \"it becomes clear that the probable error of an I.Q. score is not a constant amount, but a variable which increases as I.Q. increases. It has frequently been noted in the literature that gifted subjects show greater I.Q. fluctuation than do clinical cases with low I.Q.'s. we now see that this trend is inherent in the I.Q. technique itself, and might have been predicted on logical grounds.\". en.wikipedia.org. Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. ISBN 0-13-236273-2. \"obtained scores tend to underestimate universe scores for the bottom half of the distribution and overestimate universe scores for the top half of the distribution\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. p. 346. ISBN 0-13-236273-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Terman, Lewis Madison; Merrill, MaudeA. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. p. 44. en.wikipedia.org. Anastasi, A., & Urbina, S. (1997). Psychological Testing. 7th ed., pp. 326–327. Prentice Hall. ISBN 9780023030857. Pearson. Accessed October 10 2026. Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Neisser U. (1997). Rising Scores on Intelligence Tests. American Scientist 85: 440–7. americanscientist.org. Neisser, Ulric, ed. (1998). The Rising Curve: Long-Term Gains in IQ and Related Measures. APA Science Volume Series. Washington (DC): American Psychological Association. ISBN 978-1-55798-503-3. en.wikipedia.org. en.wikipedia.org. Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive. Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review. Flynn, James R. title=The Mean IQ of Americans: Massive Gains 1932 to 1978. (1984). Psychological Bulletin. 95: 29–51. doi. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026. Flynn, James R. (1987, March). Massive IQ Gains in 14 Nations: What IQ Tests Really Measure. Psychological Bulletin 101 (2): 171–191. doi:. American Psychological Association. psycnet.apa.org:443. en.wikipedia.org. psycnet.apa.org:443. psycnet.apa.org:443. Accessed August 22 2010. Zhou, X., Grégoire, J., & Zhu, J. (2010). The Flynn Effect and the Wechsler Scales. In L. G. Weiss, D. H. Saklofske, D. Coalson, et al. (Eds.), WAIS-IV clinical use and interpretation: Scientist-practitioner perspectives. Academic Press. ISBN 9780123750358. ScienceDirect. Qian M, Wang D, Watkins WE, et al. (2005). The effects of iodine on intelligence in children: a meta-analysis of studies conducted in China. Asia Pacific Journal of Clinical Nutrition 14 (1): 32–42. PMID 15734706. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010. Gene governs IQ boost from breastfeeding. (n.d.). physorg.com. Accessed October 10 2026. Caspi, A., Williams, B., Kim-Cohen, J., Craig, I. W., Milne, B. J., Poulton, R., Schalkwyk, L. C., Taylor, A., Werts, H., & Moffitt, T. E. (2007). Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism. Proceedings of the National Academy of Sciences, 104(47), 18860–18865. doi: 10.1073/pnas.0704292104. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine. Schellenberg, E. G. (2004). Music lessons enhance IQ. Psychol Sci 15(8): 511-4. (Klingberg et al., 2002). (n.d.). Jaeggi SM, Buschkuehl M, Jonides J, Perrig WJ. (2008). Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Sci. U.S.A. 105 (19): 6829–6833. doi:. PMID 18443283. PMC 2383929. pnas.org. pnas.org. en.wikipedia.org. National Library of Medicine. en.wikipedia.org. PubMed Central. Accessed October 10 2026. Plomin et al. (2001, 2003). Harris. (1998). Bouchard TJ. (1998). Genetic and environmental influences on adult intelligence and special mental abilities. Hum. Biol. 70 (2): 257–279. PMID 9549239. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010. Stoolmiller, M. (1999). Implications of the restricted range of family environments for estimates of heritability and nonshared environment in behavior-genetic adoption studies. Psychological Bulletin, 125(4), 392–409. doi: 10.1037/0033-2909.125.4.392. PubMed. APA PsycNet. McGue, M. et al. (2007). The Environments of Adopted and Non-adopted Youth: Evidence on Range Restriction From the Sibling Interaction and Behavior Study (SIBS). Behavior Genetics 37 (3): 449. doi:. PMID 17279339. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Socioeconomic status modifies heritability of iq in young children Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. (2003). Gottesman. Psychological Science 14 (6), 623–628. 2003. blackwell-synergy.com. Bouchard, T.J.; McGue, M. (2003). Genetic and environmental influences on human psychological differences. Journal of Neurobiology 54 (1): 4. doi:. PMID 12486697. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Dickens and Flynn. (2001). Dickens, W. T., & Flynn, J. R. (2002). The IQ Paradox: Still Resolved. Psychological Review, 109(4). Brookings Institution. Plomin R, Pedersen NL, Lichtenstein P, McClearn GE. (1994, May). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics 24 (3): 207–15. doi:. PMID 7945151. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Neisser et al. (1995, August 7). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. webspace.ship.edu. en.wikipedia.org. Accessed October 10 2026. Bouchard TJ, Lykken DT, McGue M, Segal NL, Tellegen A. (1990). Sources of human psychological differences: the Minnesota Study of Twins Reared Apart. Science 250 (4978): 223–228. doi:. PMID 2218526. sciencemag.org. science.org. en.wikipedia.org. National Library of Medicine. Commentary: The analysis of variance and the social complexities of genetic causation. (2006). by Jeremy Freese International Journal of Epidemiology 35(3):534-536. Oxford Academic. Commentary: Heritability estimates—long past their sell-by date. (2006). by Steven P R Rose Int. J. Epidemiol. 35: 525-527. Oxford Academic. Commentary: The analysis of variance is an analysis of causes (of a very circumscribed kind). (2006). Int. J. Epidemiol. 35: 527-531. Oxford Academic. Commentary: The attainability of causal knowledge of genetic effects in complex human traits. (2006). Int. J. Epidemiol. 35: 531-534. Oxford Academic. Commentary: Statistical analysis or biological analysis as tools for understanding biological causes. (2006). Int. J. Epidemiol. '35:' 536-537. Oxford Academic. The analysis of variance and the analysis of causes. (2006). Int. J. Epidemiol. 35: 520-525. Oxford Academic. Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychological Science 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Bouchard, TJ. (2004). Genetic influence on human psychological traits - A survey. Current Directions in Psychological Science 13 (4): 148–151. doi. SAGE Journals. Accessed October 10 2026. See: Ethnic Differences in Children's Intelligence Test Scores: Role of Economic Deprivation, Home Environment, and Maternal Characteristics. (n.d.). Brain Research Institute, UC Irvine College of Medicine. (n.d.). Human Intelligence Determined by Volume and Location of Gray Matter Tissue in Brain. Brain Research Institute, UC Irvine College of Medicine. sciencedaily.com. Accessed October 10 2026. Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026. Shaw P, Greenstein D, Lerch J, et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Wade, N. (2006). Scans Show Different Growth for Intelligent Brains. The New York Times. The New York Times. Accessed August 6 2006. Gosso MF, van Belzen M, de Geus EJ, et al. (2006). Association between the CHRM2 gene and intelligence in a sample of 304 Dutch families. Genes, Brain and Behavior 5 (8): 577–584. doi:. PMID 17081262. en.wikipedia.org. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Dick DM, Aliev F, Kramer J, et al. (2007). Association of CHRM2 with IQ: converging evidence for a gene influencing intelligence. Behav. Genet. 37 (2): 265–272. doi:. PMID 17160701. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Bava, S., Ballantyne, A. O., & Trauner, D. A. (2005). Disparity of verbal and performance IQ following early bilateral brain damage. Cognitive and Behavioral Neurology, 18(3), 163–170. doi: 10.1097/01.wnn.0000178228.61938.3e. PubMed. Ovid. Accessed October 10 2026. Reed, T.E., & Jensen, A.R. (1993). Cranial capacity: new Caucasian data and comments on Rushton's claimed Mongoloid-Caucasoid brain-size differences. Intelligence, 17, 423-431. McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33, 337–346. ScienceDirect. Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, pp. 220–222. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026. Okanoya K, Tokimoto N, Kumazawa N, Hihara S, Iriki A. (2008). Tool-use training in a species of rodent: the emergence of an optimal motor strategy and functional understanding. PLoS ONE 3 (3): e1860. doi:. PMID 18365015. PubMed Central. PLOS. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Jaeggi, S. M., Buschkuehl, M., Jonides, J., & Perrig, W. J. (2008). Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences, 105(19), 6829–6833. doi: 10.1073/pnas.0801268105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine. Sternberg, R. J. (2008). Increasing fluid intelligence is possible after all. Proceedings of the National Academy of Sciences, 105(19), 6791–6792. doi: 10.1073/pnas.0803396105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine. McArdle J J, Ferrer-Caja E, Hamagami F, Woodcock RW. (2002). Comparative longitudinal structural analyses of the growth and decline of multiple intellectual abilities over the life span. Dev. Psychol. 38: 115–142. PMID 11806695 Based on a sample of 1200 US individuals aged 2–95 years representative of both genders of major ethnic groups and all education levels. National Library of Medicine. Breslau N, Lucia VC, Alvarado GF. (2006). Intelligence and other predisposing factors in exposure to trauma and posttraumatic stress disorder: a follow-up study at age 17 years. Arch. Gen. Psychiatry 63 (11): 1238–1245. doi:. PMID 17088504. JAMA Network. en.wikipedia.org. National Library of Medicine. Zinkstok, J. R., de Wilde, O., van Amelsvoort, T. A. M. J., Tanck, M. W., Baas, F., & Linszen, D. H. (2007). Association between the DTNBP1 gene and intelligence: a case-control study in young patients with schizophrenia and related disorders and unaffected siblings. Behavioral and Brain Functions, 3, 19. doi: 10.1186/1744-9081-3-19. PubMed Central. Springer. National Library of Medicine. Accessed October 10 2026. Woodberry KA, Giuliano AJ, Seidman LJ. (2008). Premorbid IQ in schizophrenia: a meta-analytic review. Am J Psychiatry 165 (5): 579–587. doi:. PMID 18413704. PsychiatryOnline. en.wikipedia.org. National Library of Medicine. Sackeim HA, Freeman J, McElhiney M, Coleman E, Prudic J, Devanand DP. (1992). Effects of major depression on estimates of intelligence. J Clin Exp Neuropsychol 14 (2): 268–288. doi:. PMID 1572949. Taylor & Francis. en.wikipedia.org. National Library of Medicine. Mandelli L, Serretti A, Colombo C, et al. (2006). Improvement of cognitive functioning in mood disorder patients with depressive symptomatic recovery during treatment: an exploratory analysis. Psychiatry Clin. Neurosci. 60 (5): 598–604. doi:. PMID 16958944. blackwell-synergy.com. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Debbie A. Lawlor, University of Bristol, Heather Clark, University of Aberdeen, David A. Leon, London School of Hygiene & Tropical Medicine. (2006). Associations Between Childhood Intelligence and Hospital Admissions for Unintentional Injuries in Adulthood: The Aberdeen Children of the 1950s Cohort Study. American Journal of Public Health, December 2006. ajph.org. Accessed January 10 2007. Whalley, L. J., & Deary, I. J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. BMJ, 322(7290), 819. doi: 10.1136/bmj.322.7290.819. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026. Cervilla, J., Prince, M., Joels, S., Lovestone, S., & Mann, A. (2004, August). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Journal of Neurology, Neurosurgery & Psychiatry, 75(8), 1100–1106. doi: 10.1136/jnnp.2003.028076. PubMed Central. BMJ. National Library of Medicine. American Psychological Association. (2004, January 4). More sensitive test norms better predict which high IQ adults might develop Alzheimer's. Press release. American Psychological Association. American Psychological Association. Accessed August 6 2006. Whalley LJ, Starr JM, Athawes R, Hunter D, Pattie A, Deary IJ. (2000). Childhood mental ability and dementia. Neurology 55 (10): 1455–1459. PMID 11094097. neurology.org. en.wikipedia.org. National Library of Medicine. World Health Organization. (n.d.). Lead poisoning. WHO. World Health Organization. Accessed October 10 2026. Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026. Taylor, MD; Hart, Carole L.; Smith, George Davey; Starr, John M.; Hole, David J.; Whalley, Lawrence J.; Wilson, Valerie; Deary, Ian J. (2005). Childhood IQ and social factors on smoking behaviour, lung function and smoking-related outcomes in adulthood: linking the Scottish Mental Survey 1932 and the Midspan studies. British Journal of Health Psychology 10 (3): 399–401. doi:. PMID 16238855. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Frey MC, Detterman DK. (2004, June). Scholastic Assessment or g? The relationship between the Scholastic Assessment Test and general cognitive ability. Psychological Science 15 (6): 373–8. doi:. PMID 15147489. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Ritchie, S. J., & Tucker-Drob, E. M. (2018). How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 29(8), 1358–1369. labs.la.utexas.edu. Accessed October 10 2026. Schmidt, Frank L.; Hunter, John E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin 124: 262. doi. psycnet.apa.org:443. Hunter, J. E. and Hunter, R. F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96, 72–98. Warner MH, Ernst J, Townes BD, Peel J, Preston M. (1987). Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R. J Clin Exp Neuropsychol 9 (5): 545–562. doi:. PMID 3667899. Taylor & Francis. en.wikipedia.org. National Library of Medicine. Marley W. Watkins, Pui-Wa Lei and Gary L. Canivez. (2007). Psychometric intelligence and achievement: A cross-lagged panel analysis, Intelligence, 35, 59-68. Treena Eileen Rohde and Lee Anne Thompson. (2007). Predicting academic achievement with cognitive ability, Intelligence, 35, 83-92. Detterman and Daniel, 1989. (n.d.). Hunt, E. (1995, July–August). The role of intelligence in modern society. American Scientist, section: Nonlinearities in Intelligence. Archived May 21, 2006. Internet Archive. americanscientist.org. Accessed October 10 2026. Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology, 75:297–300. Murray, Charles. (1998). Income Inequality and IQ, AEI Press PDF. aei.org. Accessed October 10 2026. Henderson, M. (2007, April 25). Brains don't make you rich, IQ study finds. The Times (London). Accessed May 5 2010. Original online source unavailable. Bowles, S., & Gintis, H. (2002). The inheritance of inequality. Journal of Economic Perspectives, 16(3), 3–30. doi: 10.1257/089533002760278686. American Economic Association. McDaniel, M. A. (2006). Estimating state IQ: Measurement challenges and preliminary correlates. Intelligence, 34(6), 607–619. doi: 10.1016/j.intell.2006.08.007. ScienceDirect. Tambs K, Sundet JM, Magnus P, Berg K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav Genet. 1989 Mar;19(2):209–22. PMID 2719624. National Library of Medicine. Rowe, D. C., W. J. Vesterdal, and J. L. Rodgers. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. University of Arizona, 1997. Dürlinger, F., & Pietschnig, J. (2022). Meta-analyzing intelligence and religiosity associations: Evidence from the multiverse. PLOS ONE, 17(2), e0262699. PLOS. Accessed October 10 2026. Douglas N. (2006). Jackson and J. Philippe Rushton, Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test, Intelligence, Volume 34, Issue 5, September–October 2006, Pages 479-486. Lynn, R., & Irwing, P. (2004). Sex differences on the Progressive Matrices: A meta-analysis. Intelligence, 32, 481-498. Deary, I.J., Irwing, P., Der, G., & Bates, T.C. (2007). Brother–sister differences in the g factor in intelligence: Analysis of full, opposite-sex siblings from the NLSY1979. Intelligence, 35(5): 451-456. Biswas-Diener, R. (n.d.). Intelligence. Noba. nobaproject.com. Accessed October 10 2026. Publications. (n.d.). rlynn.co.uk. Accessed October 10 2026. Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, p. 173. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026. Brody, Nathan chapter=To g or Not to g—That Is the Question. (2005). Wilhelm, Oliver & Engle, Randall W. (Eds.). ed. Handbook of Understanding and Measuring Intelligence. Thousand Oaks (CA): SAGE Publications. en.wikipedia.org. Bernie Devlin, Stephen E. Fienberg, Daniel P. Resnick & Kathryn Roeder, ed. (1997). Intelligence, Genes, and Success: Scientists Respond to the Bell Curve. New York (NY): Springer Verlag. ISBN 0-38798234-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Nisbett, R. E. (2009). Intelligence and How to Get It: Why Schools and Cultures Count. W. W. Norton. ISBN 9780393065053. W. W. Norton. Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, Chapter 8. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026. [Referenced web resource]. (n.d.). (PDF). rand.org. Accessed October 10 2026. Kilburn, M. R., Hanser, L. M., & Klerman, J. A. (1998). Estimating AFQT scores for National Educational Longitudinal Study (NELS) respondents. RAND Corporation, report MR-818-OSD/A, Chapter 2. RAND Corporation. Social Security Administration. (n.d.). ssa.gov. Accessed October 10 2026. Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review. Lemann, N. (1999, March 29). The IQ meritocracy. TIME. TIME. Davis, B. D. (1983, Fall). Neo-Lysenkoism, IQ, and the press. The Public Interest, 73, 41–59. National Affairs — The Public Interest archive. Models and muddles of heritability. (n.d.). Genetica, 99, 97-108. PubMed. Schönemann, P. H. (1983). Do IQ tests really measure intelligence? Commentary, The Behavioral and Brain Sciences, 6, 311-313. The Waning of I.Q. (n.d.). by David Brooks, The New York Times. The New York Times. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026. Verney, S. P., Granholm, E., Marshall, S. P., Malcarne, V. L., & Saccuzzo, D. P. (2005). Culture-fair cognitive ability assessment: Information processing and psychophysiological approaches. Assessment, 12(3), 303–319. doi: 10.1177/1073191105276674. PubMed. Shuttleworth-Edwards AB, Kemp RD, Rust AL, Muirhead JG, Hartman NP, Radloff SE. (2004). Cross-cultural effects on IQ test performance: a review and preliminary normative indications on WAIS-III test performance. J Clin Exp Neuropsychol 26 (7): 903–920. doi:. PMID 15742541. Taylor & Francis. en.wikipedia.org. National Library of Medicine. Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons. (2004). 1*, Leah K. Hamilton1, Betty R. Onyura1 and Andrew S. Winston International Journal of Selection and Assessment Volume 14 Issue 3 Page 278 - September 2006. blackwell-synergy.com. Edelson, M. G. (2006). Are the majority of children with autism mentally retarded? a systematic evaluation of the data. Focus on Autism and Other Developmental Disabilities, 21(2), 66–83. doi: 10.1177/10883576060210020301. SAGE Journals. Accessed October 10 2026. American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (2014). Standards for Educational and Psychological Testing. American Educational Research Association. testingstandards.net. Accessed October 10 2026. Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report. Planned Parenthood Sex IQ. (2008). Archived from the original on July 6, 2008. Internet Archive. plannedparenthood.org. Accessed October 10 2026. NL Holdem Poker IQ Test. (n.d.). testyourpoker.com. Accessed October 10 2026. American Football IQ. (n.d.). footballiqtest.com. Accessed October 10 2026. Carroll, J.B. (1993). Human cognitive abilities: A survey of factor-analytical studies. New York: Cambridge University Press. ISBN 0-521-38275-0. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Lahn, B.T.; Ebenstein, L. (2009). Let's celebrate human genetic diversity. nature (journal) 461 (7265): 726–728. doi:. PMID 19812654. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Coward, W.M.; Sacket, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology 75: 297–300. doi. en.wikipedia.org. psycnet.apa.org:443. Duncan, J. et al. (2000). A neural basis for general intelligence. Science 289 (5478): 457–60. doi:. PMID 10903207. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine. Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026. Flynn, J.R. (1999). Searching for Justice: The discovery of IQ gains over time. (PDF). American Psychologist 54: 5–20. doi. sites.stat.columbia.edu. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026. Frey, M.C.; Detterman, D.K. (2003). Scholastic assessment or g? The relationship between the scholastic assessment test and general cognitive ability. Psychological Science 15 (6): 373–378. doi:. PMID 15147489. en.wikipedia.org. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026. Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). What Are Intelligence and Creativity? Psychology 2e. OpenStax, Rice University. openstax.org. Accessed October 10 2026. Gottfredson, L.S. (1998). The general intelligence factor. (PDF). Scientific American Presents 9 (4): 24–29. udel.edu. Accessed October 10 2026. Gottfredson, L.S. (2005). Suppressing intelligence research: Hurting those we intend to help. In Wright, R.H. and Cummings, N.A (Eds.) (PDF). Destructive trends in mental health: The well-intentioned path to harm. New York: Taylor and Francis. pp. 155–186. ISBN 0-415-95086-4. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026. Gottfredson, L.S. (2006). Social consequences of group differences in cognitive ability (Consequencias sociais das diferencas de grupo em habilidade cognitiva). In Flores-Mendoza, C.E. and Colom, R. (Eds.) (PDF). Introdução à psicologia das diferenças individuais. Porto Alegre, Brazil: ArtMed Publishers. pp. 155–186. ISBN 8-536-30621-1. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026. Gould, S.J. (1996). W. W. Norton & Co. ed. The Mismeasure of Man: Revised and Expanded Edition. New-York: Penguin. ISBN 0140258248. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Gray, J.R.; Chabris, C.F.; Brave,r T.S. (2003). Neural mechanisms of general fluid intelligence. Nat. Neurosci. 6 (3): 316–22. doi:. PMID 12592404. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Gray JR, Thompson PM. (2004). Neurobiology of intelligence: science and ethics. Nat. Rev. Neurosci. 5 (6): 471–82. doi:. PMID 15152197. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Rosalind Franklin University. (2021). Massive study led by Rosalind Franklin University neuroscientists reveals few differences between men and women’s brains. Rosalind Franklin University. rosalindfranklin.edu. Accessed October 10 2026. Harris, J.R. (1998). The nurture assumption : why children turn out the way they do. New York (NY): Free Press. ISBN 0-684-84409-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Hunt, E. (2001). Multiple views of multiple intelligence. [Review of Intelligence Reframed: Multiple Intelligences for the 21st Century.]. Contemporary Psychology 46: 5–7. Jensen, A.R. (1979). Bias in mental testing. New York (NY): Free Press. ISBN 0-029-16430-3. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Jensen, A.R. (1979). The g Factor: The Science of Mental Ability. Wesport (CT): Praeger Publishers. ISBN 0-275-96103-6. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Jensen, A.R. (2006). Clocking the Mind: Mental Chronometry and Individual Differences. Elsevier. ISBN 0-080-44939-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Kaufman, A.S. (2009). IQ Testing 101. New York (NY): Springer Publishing. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Klingberg, T.; Forssberg, H.; Westerberg, H. (2002). Training of working memory in children with Attention-deficit/hyperactivity disorder (ADHD). J Clin Exp Neuropsychol 24 (6): 781–91. doi:. PMID 12424652. Taylor & Francis. en.wikipedia.org. National Library of Medicine. McClearn, G.E. et al. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science 276 (5318): 1560–1563. doi:. PMID 9171059. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine. Bratsberg, B., & Rogeberg, O. (2018). Flynn effect and its reversal are both environmentally caused. Proceedings of the National Academy of Sciences, 115(26), 6674–6678. PubMed Central. Accessed October 8 2026. Murray, C. (1998). (PDF). Income Inequality and IQ. Washington (DC): AEI Press. ISBN 0-8447-7094-9. aei.org. en.wikipedia.org. en.wikipedia.org. aei.org. Accessed October 10 2026. Noguera, P.A. (2001). Racial politics and the elusive quest for excellence and equity in education. Motion Magazine. Article # ER010930002. inmotionmagazine.com. Accessed October 10 2026. Plomin, R.; DeFries, J.C.; Craig, I.W.; McGuffin, P. (2003). Behavioral genetics in the postgenomic era. Washington (DC): American Psychological Association. ISBN 1-557-98926-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed August 6 2006. Plomin, R.; DeFries, J.C.; McClearn, G.E.; McGuffin, P. (2000). Behavioral genetics. (4th ed.). New York (NY): Worth Publishers Scientific American Presents. ISBN 0-716-75159-3. en.wikipedia.org. en.wikipedia.org. Rowe, D.C.; Vesterdal, W.J.; Rodgers, J.L. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. [verification needed]. en.wikipedia.org. Schoenemann PT, Sheehan MJ, Glotzer LD. (2005, February). Prefrontal white matter volume is disproportionately larger in humans than in other primates. Nature Neuroscience 8 (2): 242–52. doi:. PMID 15665874. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Shaw, P. et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Tambs, K.; Sundet, J.M.; Magnus, P.; Berg, K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav. Genet. 19 (2): 209–22. doi:. PMID 2719624. en.wikipedia.org. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Thompson, P.M. et al. (2001). Genetic influences on brain structure. Nat. Neurosci. 4 (12): 1253–1258. doi:. PMID 11694885. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026. Wechsler, D. (1997). Wechsler Adult Intelligence Scale. (3rd ed.). San Antonia (TX): The Psychological Corporation. Wechsler, D. (2003). Wechsler Intelligence Scale for Children. (4th ed.). San Antonia (TX): The Psychological Corporation. Weiss, V. (2009). National IQ means transformed from Programme for International Student Assessment (PISA) Scores. The Journal of Social, Political and Economic Studies 31 (1): 71–94. mpra.ub.uni-muenchen.de. en.wikipedia.org. Accessed October 10 2026. The Return of Determinism? (n.d.). External links Human Intelligence: biographical profiles, current controversies, resources for teachers Classics in the History of Psychology About MentalHealth.com MentalHealth.com helps people understand themselves, build healthier relationships, and access the right care. We bring together mental health education, diagnostics, and care management to support well-being throughout every phase of life. Related community Assessments & Diagnosis Explore questions about mental health assessments, diagnostic language, and the evaluation process. 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J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. p. 15. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive.","url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. 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Annual Review of Genetics, 35, 83-101."},{"@type":"CreativeWork","name":"Galton, F. (1865). Hereditary talent and character. Classics in the history of psychology. psychclassics.yorku.ca. Accessed October 10 2026.","url":"http://psychclassics.yorku.ca/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Binet, A. (1916). New methods for the diagnosis of the intellectual level of subnormals. In The development of intelligence in children (E. S. Kite, Trans.). Publications of the Training School at Vineland. Original work published 1905. York University — Classics in the History of Psychology. Accessed July 10 2010.","url":"https://psychclassics.yorku.ca/Binet/binet1.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Wallin, J. E. W. (1911). The new clinical psychology and the psycho-clinicist. Journal of Educational Psychology, 2(4), 191-210."},{"@type":"CreativeWork","name":"Spearman, C. (1904). General intelligence. objectively determined and measured. American Journal of Psychology, 15(2), 201-293."},{"@type":"CreativeWork","name":"Mayrhauser, R. T. V. (1992). The mental testing community and validity: A prehistory. American Psychologist, 47(2), 244-253."},{"@type":"CreativeWork","name":"Richardson, T. E. (2003). Howard Andrew Knox and the origins of performance testing on Ellis Island, 1212-1216. History of Psychology, 6(2), 143-170."},{"@type":"CreativeWork","name":"Terman, L. M., Lyman, G., Ordahl, G., Ordahl, L., Galbreath, N., and Talbert, W. (1915). The Stanford revision of the Binet-Simon scale and some results from its application to 1000 non-selected children. The Journal of Educational Psychology, 6(9), 551-562."},{"@type":"CreativeWork","name":"Carmichael, L. (1957). Robert Mearns Yerkes. The Psychological Review, 64(1), 1-7."},{"@type":"CreativeWork","name":"Yerkes, R. (1919). Report of the psychology committee of the national research council. The Psychological Review, 26(2), 83-149."},{"@type":"CreativeWork","name":"Driskell, J. E., & Olmstead, B. (1989). Psychology and the military: Research applications and trends. American Psychologist, 44(1), 43-54."},{"@type":"CreativeWork","name":"Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581."},{"@type":"CreativeWork","name":"Keene, J. D. (1994). Intelligence and morale in the army of a democracy: The genesis of military psychology during the First World War. Military Psychology, 6(4), 235-253."},{"@type":"CreativeWork","name":"Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581."},{"@type":"CreativeWork","name":"Kennedy, C. H., & McNeil, J. A. (2006). A history of military psychology. In C. H. Kennedy, E. A. Zillmer (Eds.), Military Psychology: Clinical and Operational Applications (pp.1-17). New York: Guilford Publications."},{"@type":"CreativeWork","name":"Katzell, R. A., & Austin, J. T. (1992). From then to now: the development of industrial-organizational psychology in the United States. Journal of Applied Psychology. 77(6), 803-835."},{"@type":"CreativeWork","name":"Goddard, H. H. (1921). The sub-normal mind versus the abnormal. Journal of Abnormal Psychology, 16(1), 47-54."},{"@type":"CreativeWork","name":"Alper, T. G., & Boring, E. G. (1944). Intelligence-test scores of northern and southern white and negro recruits in 1918. Journal of Abnormal & Social Psychology, 39(4), 471-474."},{"@type":"CreativeWork","name":"Thurstone, L. L. (1934). The vectors of mind. Psychological Review, 41, 1-32."},{"@type":"CreativeWork","name":"Terman, L. M. (1924). The mental test as a psychological method. The Psychological Review, 31(2), 93-117."},{"@type":"CreativeWork","name":"Garrett, H. E. (1945). A note on the intelligence scores of negroes and whites in 1918. Journal of Abnormal & Social Psychology, 40(3), 344-346."},{"@type":"CreativeWork","name":"Rembis, M. A. (2004). I ain't been reading while on parole. Experts, mental tests, and eugenic commitment law in Illinois, 1890-1940. History of Psychology, 7(3), 225-247."},{"@type":"CreativeWork","name":"IQ — APA Dictionary of Psychology. (n.d.). American Psychological Association.","url":"https://dictionary.apa.org/iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Pinneau, Samuel R. (1961). Changes in Intelligence Quotient Infancy to Maturity: New Insights from the Berkeley Growth Study with Implications for the Stanford-Binet Scales and Applications to Professional Practice. Boston: Houghton Mifflin."},{"@type":"CreativeWork","name":"Mussen, Paul Henry. (1973). Psychology: An Introduction. Lexington (MA): Heath. p. 363. ISBN 0-669-61383-7. \"The I.Q. is essentially a rank; there are no true \"units\" of intellectual ability.\". en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Truch, Steve. (1993). The WISC-III Companion: A Guide to Interpretation and Educational Intervention. Austin (TX): Pro-Ed. p. 35. ISBN 0890795851. \"An IQ score is not an equal-interval score, as is evident in Table A.4 in the WISC-III manual.\". en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bartholomew, D. J. (2004). Measuring Intelligence: Facts and Fallacies. Cambridge University Press, p. 50. ISBN 9780521544788. Cambridge University Press.","url":"https://www.cambridge.org/core/books/measuring-intelligence/9EFB4DAA867F73021C145B41D3F49015?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. pp. 30–31. ISBN 0-19-852367-X. \"In the jargon of psychological measurement theory, IQ is an ordinal scale, where we are simply rank-ordering people. It is not even appropriate to claim that the 10-point difference between IQ scores of 110 and 100 is the same as the 10-point difference between IQs of 160 and 150\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Perleth, Christoph; Schatz, Tanja; Mönks, Franz J. (2000). Early Identification of High Ability. In Heller, Kurt A. Mönks, Franz J. Sternberg, Robert J. et al. International Handbook of Giftedness and Talent (2nd ed.). Amsterdam: Pergamon. p. 301. ISBN 978-0-08-043796-5. \"norm tables that provide you with such extreme values are constructed on the basis of random extrapolation and smoothing but not on the basis of empirical data of representative samples.\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Robert_Sternberg?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Terman, Lewis Madison; Merrill, Maude A. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. \"it becomes clear that the probable error of an I.Q. score is not a constant amount, but a variable which increases as I.Q. increases. It has frequently been noted in the literature that gifted subjects show greater I.Q. fluctuation than do clinical cases with low I.Q.'s. we now see that this trend is inherent in the I.Q. technique itself, and might have been predicted on logical grounds.\". en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Lewis_Terman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. ISBN 0-13-236273-2. \"obtained scores tend to underestimate universe scores for the bottom half of the distribution and overestimate universe scores for the top half of the distribution\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Prentice_Hall?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. p. 346. ISBN 0-13-236273-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Prentice_Hall?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Alan_S._Kaufman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Terman, Lewis Madison; Merrill, MaudeA. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. p. 44. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Lewis_Terman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Anastasi, A., & Urbina, S. (1997). Psychological Testing. 7th ed., pp. 326–327. Prentice Hall. ISBN 9780023030857. Pearson. Accessed October 10 2026.","url":"https://www.pearson.com/en-us/subject-catalog/p/redirected-product/P200000002697/9780023030857?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Alan_S._Kaufman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser U. (1997). Rising Scores on Intelligence Tests. American Scientist 85: 440–7. americanscientist.org.","url":"https://www.americanscientist.org/issues/feature/rising-scores-on-intelligence-tests/1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser, Ulric, ed. (1998). The Rising Curve: Long-Term Gains in IQ and Related Measures. APA Science Volume Series. Washington (DC): American Psychological Association. ISBN 978-1-55798-503-3. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive.","url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.","url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Flynn, James R. title=The Mean IQ of Americans: Massive Gains 1932 to 1978. (1984). Psychological Bulletin. 95: 29–51. doi. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Psychological_Bulletin?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Flynn, James R. (1987, March). Massive IQ Gains in 14 Nations: What IQ Tests Really Measure. Psychological Bulletin 101 (2): 171–191. doi:. American Psychological Association. psycnet.apa.org:443. en.wikipedia.org. psycnet.apa.org:443. psycnet.apa.org:443. Accessed August 22 2010.","url":"https://psycnet.apa.org:443/index.cfm?fa=buy.optionToBuy&id=2008-10701-001&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Zhou, X., Grégoire, J., & Zhu, J. (2010). The Flynn Effect and the Wechsler Scales. In L. G. Weiss, D. H. Saklofske, D. Coalson, et al. (Eds.), WAIS-IV clinical use and interpretation: Scientist-practitioner perspectives. Academic Press. ISBN 9780123750358. ScienceDirect.","url":"https://www.sciencedirect.com/science/chapter/edited-volume/pii/B9780123750358100059?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com#description"},{"@type":"CreativeWork","name":"Qian M, Wang D, Watkins WE, et al. (2005). The effects of iodine on intelligence in children: a meta-analysis of studies conducted in China. Asia Pacific Journal of Clinical Nutrition 14 (1): 32–42. PMID 15734706. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.","url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gene governs IQ boost from breastfeeding. (n.d.). physorg.com. Accessed October 10 2026.","url":"https://medicalxpress.com/news/2007-11-gene-iq-boost-breastfeeding.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Caspi, A., Williams, B., Kim-Cohen, J., Craig, I. W., Milne, B. J., Poulton, R., Schalkwyk, L. C., Taylor, A., Werts, H., & Moffitt, T. E. (2007). Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism. Proceedings of the National Academy of Sciences, 104(47), 18860–18865. doi: 10.1073/pnas.0704292104. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2141867/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schellenberg, E. G. (2004). Music lessons enhance IQ. Psychol Sci 15(8): 511-4."},{"@type":"CreativeWork","name":"(Klingberg et al., 2002). (n.d.)."},{"@type":"CreativeWork","name":"Jaeggi SM, Buschkuehl M, Jonides J, Perrig WJ. (2008). Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Sci. U.S.A. 105 (19): 6829–6833. doi:. PMID 18443283. PMC 2383929. pnas.org. pnas.org. en.wikipedia.org. National Library of Medicine. en.wikipedia.org. PubMed Central. Accessed October 10 2026.","url":"https://www.pnas.org/cgi/content/abstract/0801268105v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Plomin et al. (2001, 2003)."},{"@type":"CreativeWork","name":"Harris. (1998)."},{"@type":"CreativeWork","name":"Bouchard TJ. (1998). Genetic and environmental influences on adult intelligence and special mental abilities. Hum. Biol. 70 (2): 257–279. PMID 9549239. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.","url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Stoolmiller, M. (1999). Implications of the restricted range of family environments for estimates of heritability and nonshared environment in behavior-genetic adoption studies. Psychological Bulletin, 125(4), 392–409. doi: 10.1037/0033-2909.125.4.392. PubMed. APA PsycNet.","url":"https://pubmed.ncbi.nlm.nih.gov/10414224/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"McGue, M. et al. (2007). The Environments of Adopted and Non-adopted Youth: Evidence on Range Restriction From the Sibling Interaction and Behavior Study (SIBS). Behavior Genetics 37 (3): 449. doi:. PMID 17279339. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://link.springer.com/article/10.1007/s10519-007-9142-7?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Socioeconomic status modifies heritability of iq in young children Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. (2003). Gottesman. Psychological Science 14 (6), 623–628. 2003. blackwell-synergy.com.","url":"https://onlinelibrary.wiley.com/doi/abs/10.1046/j.0956-7976.2003.psci_1475.x?cookieSet=1&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bouchard, T.J.; McGue, M. (2003). Genetic and environmental influences on human psychological differences. Journal of Neurobiology 54 (1): 4. doi:. PMID 12486697. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://onlinelibrary.wiley.com/doi/10.1002/neu.10160?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Dickens and Flynn. (2001)."},{"@type":"CreativeWork","name":"Dickens, W. T., & Flynn, J. R. (2002). The IQ Paradox: Still Resolved. Psychological Review, 109(4). Brookings Institution.","url":"https://www.brookings.edu/wp-content/uploads/2016/06/20020205-1.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Plomin R, Pedersen NL, Lichtenstein P, McClearn GE. (1994, May). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics 24 (3): 207–15. doi:. PMID 7945151. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://link.springer.com/article/10.1007/BF01067188?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser et al. (1995, August 7). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. webspace.ship.edu. en.wikipedia.org. Accessed October 10 2026.","url":"https://webspace.ship.edu/cgboer/iku.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bouchard TJ, Lykken DT, McGue M, Segal NL, Tellegen A. (1990). Sources of human psychological differences: the Minnesota Study of Twins Reared Apart. Science 250 (4978): 223–228. doi:. PMID 2218526. sciencemag.org. science.org. en.wikipedia.org. National Library of Medicine.","url":"http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=2218526&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: The analysis of variance and the social complexities of genetic causation. (2006). by Jeremy Freese International Journal of Epidemiology 35(3):534-536. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/534/735803/Commentary-The-analysis-of-variance-and-the-social?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: Heritability estimates—long past their sell-by date. (2006). by Steven P R Rose Int. J. Epidemiol. 35: 525-527. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/525/735798/Commentary-Heritability-estimateslong-past-their?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: The analysis of variance is an analysis of causes (of a very circumscribed kind). (2006). Int. J. Epidemiol. 35: 527-531. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/527/735793/Commentary-The-analysis-of-variance-is-an-analysis?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: The attainability of causal knowledge of genetic effects in complex human traits. (2006). Int. J. Epidemiol. 35: 531-534. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/531/735806/Commentary-The-attainability-of-causal-knowledge?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: Statistical analysis or biological analysis as tools for understanding biological causes. (2006). Int. J. Epidemiol. '35:' 536-537. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/536/735821/Commentary-Statistical-analysis-or-biological?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"The analysis of variance and the analysis of causes. (2006). Int. J. Epidemiol. 35: 520-525. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/520/735787/The-analysis-of-variance-and-the-analysis-of?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychological Science 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bouchard, TJ. (2004). Genetic influence on human psychological traits - A survey. Current Directions in Psychological Science 13 (4): 148–151. doi. SAGE Journals. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1111/j.0963-7214.2004.00295.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"See: Ethnic Differences in Children's Intelligence Test Scores: Role of Economic Deprivation, Home Environment, and Maternal Characteristics. (n.d.)."},{"@type":"CreativeWork","name":"Brain Research Institute, UC Irvine College of Medicine. (n.d.). Human Intelligence Determined by Volume and Location of Gray Matter Tissue in Brain. Brain Research Institute, UC Irvine College of Medicine. sciencedaily.com. Accessed October 10 2026.","url":"https://www.sciencedaily.com/releases/2004/07/040720090419.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.","url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Shaw P, Greenstein D, Lerch J, et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://www.nature.com/articles/nature04513?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Wade, N. (2006). Scans Show Different Growth for Intelligent Brains. The New York Times. The New York Times. Accessed August 6 2006.","url":"https://www.nytimes.com/2006/03/30/science/30brain.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gosso MF, van Belzen M, de Geus EJ, et al. (2006). Association between the CHRM2 gene and intelligence in a sample of 304 Dutch families. Genes, Brain and Behavior 5 (8): 577–584. doi:. PMID 17081262. en.wikipedia.org. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Genes,_Brain_and_Behavior?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Dick DM, Aliev F, Kramer J, et al. (2007). Association of CHRM2 with IQ: converging evidence for a gene influencing intelligence. Behav. Genet. 37 (2): 265–272. doi:. PMID 17160701. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://link.springer.com/article/10.1007/s10519-006-9131-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bava, S., Ballantyne, A. O., & Trauner, D. A. (2005). Disparity of verbal and performance IQ following early bilateral brain damage. Cognitive and Behavioral Neurology, 18(3), 163–170. doi: 10.1097/01.wnn.0000178228.61938.3e. PubMed. Ovid. Accessed October 10 2026.","url":"https://pubmed.ncbi.nlm.nih.gov/16175020/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Reed, T.E., & Jensen, A.R. (1993). Cranial capacity: new Caucasian data and comments on Rushton's claimed Mongoloid-Caucasoid brain-size differences. Intelligence, 17, 423-431."},{"@type":"CreativeWork","name":"McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33, 337–346. ScienceDirect.","url":"https://www.sciencedirect.com/science/article/pii/S0160289604001357?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, pp. 220–222. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.","url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Okanoya K, Tokimoto N, Kumazawa N, Hihara S, Iriki A. (2008). Tool-use training in a species of rodent: the emergence of an optimal motor strategy and functional understanding. PLoS ONE 3 (3): e1860. doi:. PMID 18365015. PubMed Central. PLOS. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2268009/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Jaeggi, S. M., Buschkuehl, M., Jonides, J., & Perrig, W. J. (2008). Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences, 105(19), 6829–6833. doi: 10.1073/pnas.0801268105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383929/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Sternberg, R. J. (2008). Increasing fluid intelligence is possible after all. Proceedings of the National Academy of Sciences, 105(19), 6791–6792. doi: 10.1073/pnas.0803396105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383939/"},{"@type":"CreativeWork","name":"McArdle J J, Ferrer-Caja E, Hamagami F, Woodcock RW. (2002). Comparative longitudinal structural analyses of the growth and decline of multiple intellectual abilities over the life span. Dev. Psychol. 38: 115–142. PMID 11806695 Based on a sample of 1200 US individuals aged 2–95 years representative of both genders of major ethnic groups and all education levels. National Library of Medicine.","url":"https://pubmed.ncbi.nlm.nih.gov/11806695/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Breslau N, Lucia VC, Alvarado GF. (2006). Intelligence and other predisposing factors in exposure to trauma and posttraumatic stress disorder: a follow-up study at age 17 years. Arch. Gen. Psychiatry 63 (11): 1238–1245. doi:. PMID 17088504. JAMA Network. en.wikipedia.org. National Library of Medicine.","url":"https://jamanetwork.com/article.aspx?doi=10.1001%2Farchpsyc.63.11.1238&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Zinkstok, J. R., de Wilde, O., van Amelsvoort, T. A. M. J., Tanck, M. W., Baas, F., & Linszen, D. H. (2007). Association between the DTNBP1 gene and intelligence: a case-control study in young patients with schizophrenia and related disorders and unaffected siblings. Behavioral and Brain Functions, 3, 19. doi: 10.1186/1744-9081-3-19. PubMed Central. Springer. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1864987/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Woodberry KA, Giuliano AJ, Seidman LJ. (2008). Premorbid IQ in schizophrenia: a meta-analytic review. Am J Psychiatry 165 (5): 579–587. doi:. PMID 18413704. PsychiatryOnline. en.wikipedia.org. National Library of Medicine.","url":"https://psychiatryonline.org/doi/10.1176/appi.ajp.2008.07081242?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Sackeim HA, Freeman J, McElhiney M, Coleman E, Prudic J, Devanand DP. (1992). Effects of major depression on estimates of intelligence. J Clin Exp Neuropsychol 14 (2): 268–288. doi:. PMID 1572949. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1080/01688639208402828?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Mandelli L, Serretti A, Colombo C, et al. (2006). Improvement of cognitive functioning in mood disorder patients with depressive symptomatic recovery during treatment: an exploratory analysis. Psychiatry Clin. Neurosci. 60 (5): 598–604. doi:. PMID 16958944. blackwell-synergy.com. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1819.2006.01564.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Debbie A. Lawlor, University of Bristol, Heather Clark, University of Aberdeen, David A. Leon, London School of Hygiene & Tropical Medicine. (2006). Associations Between Childhood Intelligence and Hospital Admissions for Unintentional Injuries in Adulthood: The Aberdeen Children of the 1950s Cohort Study. American Journal of Public Health, December 2006. ajph.org. Accessed January 10 2007.","url":"https://www.ajph.org/cgi/content/abstract/AJPH.2005.080168v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Whalley, L. J., & Deary, I. J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. BMJ, 322(7290), 819. doi: 10.1136/bmj.322.7290.819. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC30556/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Cervilla, J., Prince, M., Joels, S., Lovestone, S., & Mann, A. (2004, August). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Journal of Neurology, Neurosurgery & Psychiatry, 75(8), 1100–1106. doi: 10.1136/jnnp.2003.028076. PubMed Central. BMJ. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1739178/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"American Psychological Association. (2004, January 4). More sensitive test norms better predict which high IQ adults might develop Alzheimer's. Press release. American Psychological Association. American Psychological Association. Accessed August 6 2006.","url":"https://www.apa.org/news/press/releases/2004/01/alzheimers-iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Whalley LJ, Starr JM, Athawes R, Hunter D, Pattie A, Deary IJ. (2000). Childhood mental ability and dementia. Neurology 55 (10): 1455–1459. PMID 11094097. neurology.org. en.wikipedia.org. National Library of Medicine.","url":"https://www.neurology.org/cgi/pmidlookup?view=long&pmid=11094097&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"World Health Organization. (n.d.). Lead poisoning. WHO. World Health Organization. Accessed October 10 2026.","url":"https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/"},{"@type":"CreativeWork","name":"Taylor, MD; Hart, Carole L.; Smith, George Davey; Starr, John M.; Hole, David J.; Whalley, Lawrence J.; Wilson, Valerie; Deary, Ian J. (2005). Childhood IQ and social factors on smoking behaviour, lung function and smoking-related outcomes in adulthood: linking the Scottish Mental Survey 1932 and the Midspan studies. British Journal of Health Psychology 10 (3): 399–401. doi:. PMID 16238855. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://bpspsychub.onlinelibrary.wiley.com/doi/10.1348/135910705X25075?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Frey MC, Detterman DK. (2004, June). Scholastic Assessment or g? The relationship between the Scholastic Assessment Test and general cognitive ability. Psychological Science 15 (6): 373–8. doi:. PMID 15147489. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1111/j.0956-7976.2004.00687.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Ritchie, S. J., & Tucker-Drob, E. M. (2018). How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 29(8), 1358–1369. labs.la.utexas.edu. Accessed October 10 2026.","url":"https://labs.la.utexas.edu/tucker-drob/files/2019/08/Ritchie-Tucker-Drob-2018-Psych-Science-How-Much-Does-Education-Improve-Intelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schmidt, Frank L.; Hunter, John E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin 124: 262. doi. psycnet.apa.org:443.","url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.124.2.262&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Hunter, J. E. and Hunter, R. F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96, 72–98."},{"@type":"CreativeWork","name":"Warner MH, Ernst J, Townes BD, Peel J, Preston M. (1987). Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R. J Clin Exp Neuropsychol 9 (5): 545–562. doi:. PMID 3667899. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1080/01688638708410768?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Marley W. Watkins, Pui-Wa Lei and Gary L. Canivez. (2007). Psychometric intelligence and achievement: A cross-lagged panel analysis, Intelligence, 35, 59-68."},{"@type":"CreativeWork","name":"Treena Eileen Rohde and Lee Anne Thompson. (2007). Predicting academic achievement with cognitive ability, Intelligence, 35, 83-92."},{"@type":"CreativeWork","name":"Detterman and Daniel, 1989. (n.d.)."},{"@type":"CreativeWork","name":"Hunt, E. (1995, July–August). The role of intelligence in modern society. American Scientist, section: Nonlinearities in Intelligence. Archived May 21, 2006. Internet Archive. americanscientist.org. Accessed October 10 2026.","url":"https://web.archive.org/web/20060521185816/http://www.americanscientist.org/template/AssetDetail/assetid/24538/page/4?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology, 75:297–300."},{"@type":"CreativeWork","name":"Murray, Charles. (1998). Income Inequality and IQ, AEI Press PDF. aei.org. Accessed October 10 2026.","url":"https://www.aei.org/wp-content/uploads/2011/10/20040302_book443.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Henderson, M. (2007, April 25). Brains don't make you rich, IQ study finds. The Times (London). Accessed May 5 2010. Original online source unavailable."},{"@type":"CreativeWork","name":"Bowles, S., & Gintis, H. (2002). The inheritance of inequality. Journal of Economic Perspectives, 16(3), 3–30. doi: 10.1257/089533002760278686. American Economic Association.","url":"https://www.aeaweb.org/articles?id=10.1257/089533002760278686&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"McDaniel, M. A. (2006). Estimating state IQ: Measurement challenges and preliminary correlates. Intelligence, 34(6), 607–619. doi: 10.1016/j.intell.2006.08.007. ScienceDirect.","url":"https://www.sciencedirect.com/science/article/pii/S0160289606001061?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Tambs K, Sundet JM, Magnus P, Berg K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav Genet. 1989 Mar;19(2):209–22. PMID 2719624. National Library of Medicine.","url":"https://pubmed.ncbi.nlm.nih.gov/2719624/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Rowe, D. C., W. J. Vesterdal, and J. L. Rodgers. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. University of Arizona, 1997."},{"@type":"CreativeWork","name":"Dürlinger, F., & Pietschnig, J. (2022). Meta-analyzing intelligence and religiosity associations: Evidence from the multiverse. PLOS ONE, 17(2), e0262699. PLOS. Accessed October 10 2026.","url":"https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0262699&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Douglas N. (2006). Jackson and J. Philippe Rushton, Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test, Intelligence, Volume 34, Issue 5, September–October 2006, Pages 479-486."},{"@type":"CreativeWork","name":"Lynn, R., & Irwing, P. (2004). Sex differences on the Progressive Matrices: A meta-analysis. 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Accessed October 10 2026.","url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"[Referenced web resource]. (n.d.). (PDF). rand.org. Accessed October 10 2026.","url":"https://www.rand.org/content/dam/rand/pubs/technical_reports/2005/RAND_TR193.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kilburn, M. R., Hanser, L. M., & Klerman, J. A. (1998). Estimating AFQT scores for National Educational Longitudinal Study (NELS) respondents. RAND Corporation, report MR-818-OSD/A, Chapter 2. RAND Corporation.","url":"https://www.rand.org/content/dam/rand/pubs/monograph_reports/2009/MR818.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Social Security Administration. (n.d.). ssa.gov. Accessed October 10 2026.","url":"https://www.ssa.gov/disability/professionals/bluebook/12.00-MentalDisorders-Adult.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.","url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Lemann, N. (1999, March 29). The IQ meritocracy. TIME. TIME.","url":"https://time.com/archive/6735029/the-iq-meritocracy/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Davis, B. D. (1983, Fall). Neo-Lysenkoism, IQ, and the press. The Public Interest, 73, 41–59. National Affairs — The Public Interest archive.","url":"https://nationalaffairs.com/public_interest/detail/neo-lysenkoism-iq-and-the-press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Models and muddles of heritability. (n.d.). Genetica, 99, 97-108. PubMed.","url":"https://pubmed.ncbi.nlm.nih.gov/9463078/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schönemann, P. H. (1983). Do IQ tests really measure intelligence? Commentary, The Behavioral and Brain Sciences, 6, 311-313."},{"@type":"CreativeWork","name":"The Waning of I.Q. (n.d.). by David Brooks, The New York Times. The New York Times. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","url":"http://select.nytimes.com/2007/09/14/opinion/14brooks.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Verney, S. P., Granholm, E., Marshall, S. P., Malcarne, V. L., & Saccuzzo, D. P. (2005). Culture-fair cognitive ability assessment: Information processing and psychophysiological approaches. Assessment, 12(3), 303–319. doi: 10.1177/1073191105276674. PubMed.","url":"https://pubmed.ncbi.nlm.nih.gov/16123251/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Shuttleworth-Edwards AB, Kemp RD, Rust AL, Muirhead JG, Hartman NP, Radloff SE. (2004). Cross-cultural effects on IQ test performance: a review and preliminary normative indications on WAIS-III test performance. J Clin Exp Neuropsychol 26 (7): 903–920. doi:. PMID 15742541. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1080/13803390490510824?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons. (2004). 1*, Leah K. Hamilton1, Betty R. Onyura1 and Andrew S. Winston International Journal of Selection and Assessment Volume 14 Issue 3 Page 278 - September 2006. blackwell-synergy.com.","url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1468-2389.2006.00346.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Edelson, M. G. (2006). Are the majority of children with autism mentally retarded? a systematic evaluation of the data. Focus on Autism and Other Developmental Disabilities, 21(2), 66–83. doi: 10.1177/10883576060210020301. SAGE Journals. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1177/10883576060210020301?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (2014). Standards for Educational and Psychological Testing. American Educational Research Association. testingstandards.net. Accessed October 10 2026.","url":"https://www.testingstandards.net/uploads/7/6/6/4/76643089/standards_2014edition.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report.","url":"https://www.mun.ca/biology/scarr/APA%201985%20Intelligence%20-%20Knowns%20and%20Unknowns.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Planned Parenthood Sex IQ. (2008). Archived from the original on July 6, 2008. Internet Archive. plannedparenthood.org. Accessed October 10 2026.","url":"http://web.archive.org/web/20080706120025/http://www.plannedparenthood.org/health-topics/sex-101/your-sex-iq-4328.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"NL Holdem Poker IQ Test. (n.d.). testyourpoker.com. Accessed October 10 2026.","url":"https://www.testyourpoker.com/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"American Football IQ. (n.d.). footballiqtest.com. Accessed October 10 2026.","url":"http://www.footballiqtest.com?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Carroll, J.B. (1993). Human cognitive abilities: A survey of factor-analytical studies. New York: Cambridge University Press. ISBN 0-521-38275-0. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Cambridge_University_Press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Lahn, B.T.; Ebenstein, L. (2009). Let's celebrate human genetic diversity. nature (journal) 461 (7265): 726–728. doi:. PMID 19812654. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Coward, W.M.; Sacket, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology 75: 297–300. doi. en.wikipedia.org. psycnet.apa.org:443.","url":"https://en.wikipedia.org/wiki/%20Journal_of_Applied_Psychology?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Duncan, J. et al. (2000). A neural basis for general intelligence. Science 289 (5478): 457–60. doi:. PMID 10903207. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine.","url":"https://en.wikipedia.org/wiki/%20Science_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.","url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Flynn, J.R. (1999). Searching for Justice: The discovery of IQ gains over time. (PDF). American Psychologist 54: 5–20. doi. sites.stat.columbia.edu. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026.","url":"https://sites.stat.columbia.edu/gelman/stuff_for_blog/flynn.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Frey, M.C.; Detterman, D.K. (2003). Scholastic assessment or g? The relationship between the scholastic assessment test and general cognitive ability. Psychological Science 15 (6): 373–378. doi:. PMID 15147489. en.wikipedia.org. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Psychological_Science?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/"},{"@type":"CreativeWork","name":"Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). What Are Intelligence and Creativity? Psychology 2e. OpenStax, Rice University. openstax.org. Accessed October 10 2026.","url":"https://openstax.org/books/psychology-2e/pages/7-4-what-are-intelligence-and-creativity?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gottfredson, L.S. (1998). The general intelligence factor. (PDF). Scientific American Presents 9 (4): 24–29. udel.edu. Accessed October 10 2026.","url":"https://www1.udel.edu/educ/gottfredson/reprints/1998generalintelligencefactor.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gottfredson, L.S. (2005). Suppressing intelligence research: Hurting those we intend to help. In Wright, R.H. and Cummings, N.A (Eds.) (PDF). Destructive trends in mental health: The well-intentioned path to harm. New York: Taylor and Francis. pp. 155–186. ISBN 0-415-95086-4. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","url":"https://www1.udel.edu/educ/gottfredson/reprints/2005suppressingintelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gottfredson, L.S. (2006). Social consequences of group differences in cognitive ability (Consequencias sociais das diferencas de grupo em habilidade cognitiva). In Flores-Mendoza, C.E. and Colom, R. (Eds.) (PDF). Introdução à psicologia das diferenças individuais. Porto Alegre, Brazil: ArtMed Publishers. pp. 155–186. ISBN 8-536-30621-1. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","url":"https://www1.udel.edu/educ/gottfredson/reprints/2004socialconsequences.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gould, S.J. (1996). W. W. Norton & Co. ed. The Mismeasure of Man: Revised and Expanded Edition. New-York: Penguin. ISBN 0140258248. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Stephen_Jay_Gould?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gray, J.R.; Chabris, C.F.; Brave,r T.S. (2003). Neural mechanisms of general fluid intelligence. Nat. Neurosci. 6 (3): 316–22. doi:. PMID 12592404. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Nat._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gray JR, Thompson PM. (2004). Neurobiology of intelligence: science and ethics. Nat. Rev. Neurosci. 5 (6): 471–82. doi:. PMID 15152197. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Nat._Rev._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Rosalind Franklin University. (2021). Massive study led by Rosalind Franklin University neuroscientists reveals few differences between men and women’s brains. Rosalind Franklin University. rosalindfranklin.edu. Accessed October 10 2026.","url":"https://www.rosalindfranklin.edu/news/massive-study-led-by-rosalind-franklin-university-neuroscientists-reveals-few-differences-between-men-and-women-s-brains/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Harris, J.R. (1998). The nurture assumption : why children turn out the way they do. New York (NY): Free Press. ISBN 0-684-84409-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Free_Press_(publisher)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Hunt, E. (2001). Multiple views of multiple intelligence. [Review of Intelligence Reframed: Multiple Intelligences for the 21st Century.]. Contemporary Psychology 46: 5–7."},{"@type":"CreativeWork","name":"Jensen, A.R. (1979). Bias in mental testing. New York (NY): Free Press. ISBN 0-029-16430-3. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Free_Press_(publisher)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Jensen, A.R. (1979). The g Factor: The Science of Mental Ability. Wesport (CT): Praeger Publishers. ISBN 0-275-96103-6. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Praeger_Publishers?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Jensen, A.R. (2006). Clocking the Mind: Mental Chronometry and Individual Differences. Elsevier. ISBN 0-080-44939-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Elsevier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kaufman, A.S. (2009). IQ Testing 101. New York (NY): Springer Publishing. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Springer_Publishing?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Klingberg, T.; Forssberg, H.; Westerberg, H. (2002). Training of working memory in children with Attention-deficit/hyperactivity disorder (ADHD). J Clin Exp Neuropsychol 24 (6): 781–91. doi:. PMID 12424652. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1076/jcen.24.6.781.8395?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"McClearn, G.E. et al. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science 276 (5318): 1560–1563. doi:. PMID 9171059. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine.","url":"https://en.wikipedia.org/wiki/%20Science_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bratsberg, B., & Rogeberg, O. (2018). Flynn effect and its reversal are both environmentally caused. Proceedings of the National Academy of Sciences, 115(26), 6674–6678. PubMed Central. Accessed October 8 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC6042097/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Murray, C. (1998). (PDF). Income Inequality and IQ. Washington (DC): AEI Press. ISBN 0-8447-7094-9. aei.org. en.wikipedia.org. en.wikipedia.org. aei.org. Accessed October 10 2026.","url":"https://www.aei.org/events/income-inequality-and-iq/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Noguera, P.A. (2001). Racial politics and the elusive quest for excellence and equity in education. Motion Magazine. Article # ER010930002. inmotionmagazine.com. Accessed October 10 2026.","url":"http://www.inmotionmagazine.com/er/pnrp1.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Plomin, R.; DeFries, J.C.; Craig, I.W.; McGuffin, P. (2003). Behavioral genetics in the postgenomic era. Washington (DC): American Psychological Association. ISBN 1-557-98926-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed August 6 2006.","url":"https://en.wikipedia.org/wiki/%20American_Psychological_Association?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Plomin, R.; DeFries, J.C.; McClearn, G.E.; McGuffin, P. (2000). Behavioral genetics. (4th ed.). New York (NY): Worth Publishers Scientific American Presents. ISBN 0-716-75159-3. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Rowe, D.C.; Vesterdal, W.J.; Rodgers, J.L. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. [verification needed]. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Wikipedia:Verifiability?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schoenemann PT, Sheehan MJ, Glotzer LD. (2005, February). Prefrontal white matter volume is disproportionately larger in humans than in other primates. Nature Neuroscience 8 (2): 242–52. doi:. PMID 15665874. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://www.nature.com/articles/nn1394?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Shaw, P. et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Tambs, K.; Sundet, J.M.; Magnus, P.; Berg, K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav. Genet. 19 (2): 209–22. doi:. PMID 2719624. en.wikipedia.org. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Behav._Genet.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Thompson, P.M. et al. (2001). Genetic influences on brain structure. Nat. Neurosci. 4 (12): 1253–1258. doi:. PMID 11694885. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Nat._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Wechsler, D. (1997). Wechsler Adult Intelligence Scale. (3rd ed.). San Antonia (TX): The Psychological Corporation."},{"@type":"CreativeWork","name":"Wechsler, D. (2003). Wechsler Intelligence Scale for Children. (4th ed.). San Antonia (TX): The Psychological Corporation."},{"@type":"CreativeWork","name":"Weiss, V. (2009). National IQ means transformed from Programme for International Student Assessment (PISA) Scores. The Journal of Social, Political and Economic Studies 31 (1): 71–94. mpra.ub.uni-muenchen.de. en.wikipedia.org. Accessed October 10 2026.","url":"https://mpra.ub.uni-muenchen.de/14600/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"The Return of Determinism? 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Annual Review of Genetics, 35, 83-101."},{"@type":"CreativeWork","name":"Galton, F. (1865). Hereditary talent and character. Classics in the history of psychology. psychclassics.yorku.ca. Accessed October 10 2026.","url":"http://psychclassics.yorku.ca/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Binet, A. (1916). New methods for the diagnosis of the intellectual level of subnormals. In The development of intelligence in children (E. S. Kite, Trans.). Publications of the Training School at Vineland. Original work published 1905. York University — Classics in the History of Psychology. Accessed July 10 2010.","url":"https://psychclassics.yorku.ca/Binet/binet1.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Wallin, J. E. W. (1911). The new clinical psychology and the psycho-clinicist. Journal of Educational Psychology, 2(4), 191-210."},{"@type":"CreativeWork","name":"Spearman, C. (1904). General intelligence. objectively determined and measured. American Journal of Psychology, 15(2), 201-293."},{"@type":"CreativeWork","name":"Mayrhauser, R. T. V. (1992). The mental testing community and validity: A prehistory. American Psychologist, 47(2), 244-253."},{"@type":"CreativeWork","name":"Richardson, T. E. (2003). Howard Andrew Knox and the origins of performance testing on Ellis Island, 1212-1216. History of Psychology, 6(2), 143-170."},{"@type":"CreativeWork","name":"Terman, L. M., Lyman, G., Ordahl, G., Ordahl, L., Galbreath, N., and Talbert, W. (1915). The Stanford revision of the Binet-Simon scale and some results from its application to 1000 non-selected children. The Journal of Educational Psychology, 6(9), 551-562."},{"@type":"CreativeWork","name":"Carmichael, L. (1957). Robert Mearns Yerkes. The Psychological Review, 64(1), 1-7."},{"@type":"CreativeWork","name":"Yerkes, R. (1919). Report of the psychology committee of the national research council. The Psychological Review, 26(2), 83-149."},{"@type":"CreativeWork","name":"Driskell, J. E., & Olmstead, B. (1989). Psychology and the military: Research applications and trends. American Psychologist, 44(1), 43-54."},{"@type":"CreativeWork","name":"Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581."},{"@type":"CreativeWork","name":"Keene, J. D. (1994). Intelligence and morale in the army of a democracy: The genesis of military psychology during the First World War. Military Psychology, 6(4), 235-253."},{"@type":"CreativeWork","name":"Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581."},{"@type":"CreativeWork","name":"Kennedy, C. H., & McNeil, J. A. (2006). A history of military psychology. In C. H. Kennedy, E. A. Zillmer (Eds.), Military Psychology: Clinical and Operational Applications (pp.1-17). New York: Guilford Publications."},{"@type":"CreativeWork","name":"Katzell, R. A., & Austin, J. T. (1992). From then to now: the development of industrial-organizational psychology in the United States. Journal of Applied Psychology. 77(6), 803-835."},{"@type":"CreativeWork","name":"Goddard, H. H. (1921). The sub-normal mind versus the abnormal. Journal of Abnormal Psychology, 16(1), 47-54."},{"@type":"CreativeWork","name":"Alper, T. 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Accessed June 29 2010.","url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gene governs IQ boost from breastfeeding. (n.d.). physorg.com. Accessed October 10 2026.","url":"https://medicalxpress.com/news/2007-11-gene-iq-boost-breastfeeding.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Caspi, A., Williams, B., Kim-Cohen, J., Craig, I. W., Milne, B. J., Poulton, R., Schalkwyk, L. C., Taylor, A., Werts, H., & Moffitt, T. E. (2007). Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism. Proceedings of the National Academy of Sciences, 104(47), 18860–18865. doi: 10.1073/pnas.0704292104. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2141867/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schellenberg, E. G. (2004). Music lessons enhance IQ. Psychol Sci 15(8): 511-4."},{"@type":"CreativeWork","name":"(Klingberg et al., 2002). (n.d.)."},{"@type":"CreativeWork","name":"Jaeggi SM, Buschkuehl M, Jonides J, Perrig WJ. (2008). Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Sci. U.S.A. 105 (19): 6829–6833. doi:. PMID 18443283. PMC 2383929. pnas.org. pnas.org. en.wikipedia.org. National Library of Medicine. en.wikipedia.org. PubMed Central. Accessed October 10 2026.","url":"https://www.pnas.org/cgi/content/abstract/0801268105v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Plomin et al. (2001, 2003)."},{"@type":"CreativeWork","name":"Harris. (1998)."},{"@type":"CreativeWork","name":"Bouchard TJ. (1998). Genetic and environmental influences on adult intelligence and special mental abilities. Hum. Biol. 70 (2): 257–279. PMID 9549239. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.","url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Stoolmiller, M. (1999). Implications of the restricted range of family environments for estimates of heritability and nonshared environment in behavior-genetic adoption studies. Psychological Bulletin, 125(4), 392–409. doi: 10.1037/0033-2909.125.4.392. PubMed. APA PsycNet.","url":"https://pubmed.ncbi.nlm.nih.gov/10414224/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"McGue, M. et al. (2007). The Environments of Adopted and Non-adopted Youth: Evidence on Range Restriction From the Sibling Interaction and Behavior Study (SIBS). Behavior Genetics 37 (3): 449. doi:. PMID 17279339. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://link.springer.com/article/10.1007/s10519-007-9142-7?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Socioeconomic status modifies heritability of iq in young children Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. (2003). Gottesman. Psychological Science 14 (6), 623–628. 2003. blackwell-synergy.com.","url":"https://onlinelibrary.wiley.com/doi/abs/10.1046/j.0956-7976.2003.psci_1475.x?cookieSet=1&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bouchard, T.J.; McGue, M. (2003). Genetic and environmental influences on human psychological differences. Journal of Neurobiology 54 (1): 4. doi:. PMID 12486697. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://onlinelibrary.wiley.com/doi/10.1002/neu.10160?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Dickens and Flynn. (2001)."},{"@type":"CreativeWork","name":"Dickens, W. T., & Flynn, J. R. (2002). The IQ Paradox: Still Resolved. Psychological Review, 109(4). Brookings Institution.","url":"https://www.brookings.edu/wp-content/uploads/2016/06/20020205-1.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Plomin R, Pedersen NL, Lichtenstein P, McClearn GE. (1994, May). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics 24 (3): 207–15. doi:. PMID 7945151. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://link.springer.com/article/10.1007/BF01067188?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser et al. (1995, August 7). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. webspace.ship.edu. en.wikipedia.org. Accessed October 10 2026.","url":"https://webspace.ship.edu/cgboer/iku.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bouchard TJ, Lykken DT, McGue M, Segal NL, Tellegen A. (1990). Sources of human psychological differences: the Minnesota Study of Twins Reared Apart. Science 250 (4978): 223–228. doi:. PMID 2218526. sciencemag.org. science.org. en.wikipedia.org. National Library of Medicine.","url":"http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=2218526&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: The analysis of variance and the social complexities of genetic causation. (2006). by Jeremy Freese International Journal of Epidemiology 35(3):534-536. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/534/735803/Commentary-The-analysis-of-variance-and-the-social?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: Heritability estimates—long past their sell-by date. (2006). by Steven P R Rose Int. J. Epidemiol. 35: 525-527. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/525/735798/Commentary-Heritability-estimateslong-past-their?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: The analysis of variance is an analysis of causes (of a very circumscribed kind). (2006). Int. J. Epidemiol. 35: 527-531. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/527/735793/Commentary-The-analysis-of-variance-is-an-analysis?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: The attainability of causal knowledge of genetic effects in complex human traits. (2006). Int. J. Epidemiol. 35: 531-534. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/531/735806/Commentary-The-attainability-of-causal-knowledge?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Commentary: Statistical analysis or biological analysis as tools for understanding biological causes. (2006). Int. J. Epidemiol. '35:' 536-537. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/536/735821/Commentary-Statistical-analysis-or-biological?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"The analysis of variance and the analysis of causes. (2006). Int. J. Epidemiol. 35: 520-525. Oxford Academic.","url":"https://academic.oup.com/ije/article/35/3/520/735787/The-analysis-of-variance-and-the-analysis-of?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychological Science 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bouchard, TJ. (2004). Genetic influence on human psychological traits - A survey. Current Directions in Psychological Science 13 (4): 148–151. doi. SAGE Journals. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1111/j.0963-7214.2004.00295.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"See: Ethnic Differences in Children's Intelligence Test Scores: Role of Economic Deprivation, Home Environment, and Maternal Characteristics. (n.d.)."},{"@type":"CreativeWork","name":"Brain Research Institute, UC Irvine College of Medicine. (n.d.). Human Intelligence Determined by Volume and Location of Gray Matter Tissue in Brain. Brain Research Institute, UC Irvine College of Medicine. sciencedaily.com. Accessed October 10 2026.","url":"https://www.sciencedaily.com/releases/2004/07/040720090419.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.","url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Shaw P, Greenstein D, Lerch J, et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://www.nature.com/articles/nature04513?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Wade, N. (2006). Scans Show Different Growth for Intelligent Brains. The New York Times. The New York Times. Accessed August 6 2006.","url":"https://www.nytimes.com/2006/03/30/science/30brain.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gosso MF, van Belzen M, de Geus EJ, et al. (2006). Association between the CHRM2 gene and intelligence in a sample of 304 Dutch families. Genes, Brain and Behavior 5 (8): 577–584. doi:. PMID 17081262. en.wikipedia.org. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Genes,_Brain_and_Behavior?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Dick DM, Aliev F, Kramer J, et al. (2007). Association of CHRM2 with IQ: converging evidence for a gene influencing intelligence. Behav. Genet. 37 (2): 265–272. doi:. PMID 17160701. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://link.springer.com/article/10.1007/s10519-006-9131-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Bava, S., Ballantyne, A. O., & Trauner, D. A. (2005). Disparity of verbal and performance IQ following early bilateral brain damage. Cognitive and Behavioral Neurology, 18(3), 163–170. doi: 10.1097/01.wnn.0000178228.61938.3e. PubMed. Ovid. Accessed October 10 2026.","url":"https://pubmed.ncbi.nlm.nih.gov/16175020/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Reed, T.E., & Jensen, A.R. (1993). Cranial capacity: new Caucasian data and comments on Rushton's claimed Mongoloid-Caucasoid brain-size differences. Intelligence, 17, 423-431."},{"@type":"CreativeWork","name":"McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33, 337–346. ScienceDirect.","url":"https://www.sciencedirect.com/science/article/pii/S0160289604001357?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, pp. 220–222. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.","url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Okanoya K, Tokimoto N, Kumazawa N, Hihara S, Iriki A. (2008). Tool-use training in a species of rodent: the emergence of an optimal motor strategy and functional understanding. PLoS ONE 3 (3): e1860. doi:. PMID 18365015. PubMed Central. PLOS. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2268009/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Jaeggi, S. M., Buschkuehl, M., Jonides, J., & Perrig, W. J. (2008). Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences, 105(19), 6829–6833. doi: 10.1073/pnas.0801268105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383929/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Sternberg, R. J. (2008). Increasing fluid intelligence is possible after all. Proceedings of the National Academy of Sciences, 105(19), 6791–6792. doi: 10.1073/pnas.0803396105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383939/"},{"@type":"CreativeWork","name":"McArdle J J, Ferrer-Caja E, Hamagami F, Woodcock RW. (2002). Comparative longitudinal structural analyses of the growth and decline of multiple intellectual abilities over the life span. Dev. Psychol. 38: 115–142. PMID 11806695 Based on a sample of 1200 US individuals aged 2–95 years representative of both genders of major ethnic groups and all education levels. National Library of Medicine.","url":"https://pubmed.ncbi.nlm.nih.gov/11806695/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Breslau N, Lucia VC, Alvarado GF. (2006). Intelligence and other predisposing factors in exposure to trauma and posttraumatic stress disorder: a follow-up study at age 17 years. Arch. Gen. Psychiatry 63 (11): 1238–1245. doi:. PMID 17088504. JAMA Network. en.wikipedia.org. National Library of Medicine.","url":"https://jamanetwork.com/article.aspx?doi=10.1001%2Farchpsyc.63.11.1238&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Zinkstok, J. R., de Wilde, O., van Amelsvoort, T. A. M. J., Tanck, M. W., Baas, F., & Linszen, D. H. (2007). Association between the DTNBP1 gene and intelligence: a case-control study in young patients with schizophrenia and related disorders and unaffected siblings. Behavioral and Brain Functions, 3, 19. doi: 10.1186/1744-9081-3-19. PubMed Central. Springer. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1864987/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Woodberry KA, Giuliano AJ, Seidman LJ. (2008). Premorbid IQ in schizophrenia: a meta-analytic review. Am J Psychiatry 165 (5): 579–587. doi:. PMID 18413704. PsychiatryOnline. en.wikipedia.org. National Library of Medicine.","url":"https://psychiatryonline.org/doi/10.1176/appi.ajp.2008.07081242?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Sackeim HA, Freeman J, McElhiney M, Coleman E, Prudic J, Devanand DP. (1992). Effects of major depression on estimates of intelligence. J Clin Exp Neuropsychol 14 (2): 268–288. doi:. PMID 1572949. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1080/01688639208402828?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Mandelli L, Serretti A, Colombo C, et al. (2006). Improvement of cognitive functioning in mood disorder patients with depressive symptomatic recovery during treatment: an exploratory analysis. Psychiatry Clin. Neurosci. 60 (5): 598–604. doi:. PMID 16958944. blackwell-synergy.com. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1819.2006.01564.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Debbie A. Lawlor, University of Bristol, Heather Clark, University of Aberdeen, David A. Leon, London School of Hygiene & Tropical Medicine. (2006). Associations Between Childhood Intelligence and Hospital Admissions for Unintentional Injuries in Adulthood: The Aberdeen Children of the 1950s Cohort Study. American Journal of Public Health, December 2006. ajph.org. Accessed January 10 2007.","url":"https://www.ajph.org/cgi/content/abstract/AJPH.2005.080168v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Whalley, L. J., & Deary, I. J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. BMJ, 322(7290), 819. doi: 10.1136/bmj.322.7290.819. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC30556/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Cervilla, J., Prince, M., Joels, S., Lovestone, S., & Mann, A. (2004, August). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Journal of Neurology, Neurosurgery & Psychiatry, 75(8), 1100–1106. doi: 10.1136/jnnp.2003.028076. PubMed Central. BMJ. National Library of Medicine.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1739178/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"American Psychological Association. (2004, January 4). More sensitive test norms better predict which high IQ adults might develop Alzheimer's. Press release. American Psychological Association. American Psychological Association. Accessed August 6 2006.","url":"https://www.apa.org/news/press/releases/2004/01/alzheimers-iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Whalley LJ, Starr JM, Athawes R, Hunter D, Pattie A, Deary IJ. (2000). Childhood mental ability and dementia. Neurology 55 (10): 1455–1459. PMID 11094097. neurology.org. en.wikipedia.org. National Library of Medicine.","url":"https://www.neurology.org/cgi/pmidlookup?view=long&pmid=11094097&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"World Health Organization. (n.d.). Lead poisoning. WHO. World Health Organization. Accessed October 10 2026.","url":"https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/"},{"@type":"CreativeWork","name":"Taylor, MD; Hart, Carole L.; Smith, George Davey; Starr, John M.; Hole, David J.; Whalley, Lawrence J.; Wilson, Valerie; Deary, Ian J. (2005). Childhood IQ and social factors on smoking behaviour, lung function and smoking-related outcomes in adulthood: linking the Scottish Mental Survey 1932 and the Midspan studies. British Journal of Health Psychology 10 (3): 399–401. doi:. PMID 16238855. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://bpspsychub.onlinelibrary.wiley.com/doi/10.1348/135910705X25075?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Frey MC, Detterman DK. (2004, June). Scholastic Assessment or g? The relationship between the Scholastic Assessment Test and general cognitive ability. Psychological Science 15 (6): 373–8. doi:. PMID 15147489. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1111/j.0956-7976.2004.00687.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Ritchie, S. J., & Tucker-Drob, E. M. (2018). How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 29(8), 1358–1369. labs.la.utexas.edu. Accessed October 10 2026.","url":"https://labs.la.utexas.edu/tucker-drob/files/2019/08/Ritchie-Tucker-Drob-2018-Psych-Science-How-Much-Does-Education-Improve-Intelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schmidt, Frank L.; Hunter, John E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin 124: 262. doi. psycnet.apa.org:443.","url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.124.2.262&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Hunter, J. E. and Hunter, R. F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96, 72–98."},{"@type":"CreativeWork","name":"Warner MH, Ernst J, Townes BD, Peel J, Preston M. (1987). Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R. J Clin Exp Neuropsychol 9 (5): 545–562. doi:. PMID 3667899. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1080/01688638708410768?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Marley W. Watkins, Pui-Wa Lei and Gary L. Canivez. (2007). Psychometric intelligence and achievement: A cross-lagged panel analysis, Intelligence, 35, 59-68."},{"@type":"CreativeWork","name":"Treena Eileen Rohde and Lee Anne Thompson. (2007). Predicting academic achievement with cognitive ability, Intelligence, 35, 83-92."},{"@type":"CreativeWork","name":"Detterman and Daniel, 1989. (n.d.)."},{"@type":"CreativeWork","name":"Hunt, E. (1995, July–August). The role of intelligence in modern society. American Scientist, section: Nonlinearities in Intelligence. Archived May 21, 2006. Internet Archive. americanscientist.org. Accessed October 10 2026.","url":"https://web.archive.org/web/20060521185816/http://www.americanscientist.org/template/AssetDetail/assetid/24538/page/4?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology, 75:297–300."},{"@type":"CreativeWork","name":"Murray, Charles. (1998). Income Inequality and IQ, AEI Press PDF. aei.org. Accessed October 10 2026.","url":"https://www.aei.org/wp-content/uploads/2011/10/20040302_book443.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Henderson, M. (2007, April 25). Brains don't make you rich, IQ study finds. The Times (London). Accessed May 5 2010. Original online source unavailable."},{"@type":"CreativeWork","name":"Bowles, S., & Gintis, H. (2002). The inheritance of inequality. Journal of Economic Perspectives, 16(3), 3–30. doi: 10.1257/089533002760278686. American Economic Association.","url":"https://www.aeaweb.org/articles?id=10.1257/089533002760278686&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"McDaniel, M. A. (2006). Estimating state IQ: Measurement challenges and preliminary correlates. Intelligence, 34(6), 607–619. doi: 10.1016/j.intell.2006.08.007. ScienceDirect.","url":"https://www.sciencedirect.com/science/article/pii/S0160289606001061?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Tambs K, Sundet JM, Magnus P, Berg K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav Genet. 1989 Mar;19(2):209–22. PMID 2719624. National Library of Medicine.","url":"https://pubmed.ncbi.nlm.nih.gov/2719624/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Rowe, D. C., W. J. Vesterdal, and J. L. Rodgers. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. University of Arizona, 1997."},{"@type":"CreativeWork","name":"Dürlinger, F., & Pietschnig, J. (2022). Meta-analyzing intelligence and religiosity associations: Evidence from the multiverse. PLOS ONE, 17(2), e0262699. PLOS. Accessed October 10 2026.","url":"https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0262699&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Douglas N. (2006). Jackson and J. Philippe Rushton, Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test, Intelligence, Volume 34, Issue 5, September–October 2006, Pages 479-486."},{"@type":"CreativeWork","name":"Lynn, R., & Irwing, P. (2004). Sex differences on the Progressive Matrices: A meta-analysis. 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Accessed October 10 2026.","url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"[Referenced web resource]. (n.d.). (PDF). rand.org. Accessed October 10 2026.","url":"https://www.rand.org/content/dam/rand/pubs/technical_reports/2005/RAND_TR193.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Kilburn, M. R., Hanser, L. M., & Klerman, J. A. (1998). Estimating AFQT scores for National Educational Longitudinal Study (NELS) respondents. RAND Corporation, report MR-818-OSD/A, Chapter 2. RAND Corporation.","url":"https://www.rand.org/content/dam/rand/pubs/monograph_reports/2009/MR818.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Social Security Administration. (n.d.). ssa.gov. Accessed October 10 2026.","url":"https://www.ssa.gov/disability/professionals/bluebook/12.00-MentalDisorders-Adult.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.","url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Lemann, N. (1999, March 29). The IQ meritocracy. TIME. TIME.","url":"https://time.com/archive/6735029/the-iq-meritocracy/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Davis, B. D. (1983, Fall). Neo-Lysenkoism, IQ, and the press. The Public Interest, 73, 41–59. National Affairs — The Public Interest archive.","url":"https://nationalaffairs.com/public_interest/detail/neo-lysenkoism-iq-and-the-press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Models and muddles of heritability. (n.d.). Genetica, 99, 97-108. PubMed.","url":"https://pubmed.ncbi.nlm.nih.gov/9463078/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Schönemann, P. H. (1983). Do IQ tests really measure intelligence? Commentary, The Behavioral and Brain Sciences, 6, 311-313."},{"@type":"CreativeWork","name":"The Waning of I.Q. (n.d.). by David Brooks, The New York Times. The New York Times. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","url":"http://select.nytimes.com/2007/09/14/opinion/14brooks.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Verney, S. P., Granholm, E., Marshall, S. P., Malcarne, V. L., & Saccuzzo, D. P. (2005). Culture-fair cognitive ability assessment: Information processing and psychophysiological approaches. Assessment, 12(3), 303–319. doi: 10.1177/1073191105276674. PubMed.","url":"https://pubmed.ncbi.nlm.nih.gov/16123251/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Shuttleworth-Edwards AB, Kemp RD, Rust AL, Muirhead JG, Hartman NP, Radloff SE. (2004). Cross-cultural effects on IQ test performance: a review and preliminary normative indications on WAIS-III test performance. J Clin Exp Neuropsychol 26 (7): 903–920. doi:. PMID 15742541. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","url":"https://www.tandfonline.com/doi/full/10.1080/13803390490510824?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons. (2004). 1*, Leah K. Hamilton1, Betty R. Onyura1 and Andrew S. 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Accessed October 10 2026.","url":"https://journals.sagepub.com/doi/10.1177/10883576060210020301?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (2014). Standards for Educational and Psychological Testing. American Educational Research Association. testingstandards.net. Accessed October 10 2026.","url":"https://www.testingstandards.net/uploads/7/6/6/4/76643089/standards_2014edition.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report.","url":"https://www.mun.ca/biology/scarr/APA%201985%20Intelligence%20-%20Knowns%20and%20Unknowns.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Planned Parenthood Sex IQ. (2008). Archived from the original on July 6, 2008. Internet Archive. plannedparenthood.org. Accessed October 10 2026.","url":"http://web.archive.org/web/20080706120025/http://www.plannedparenthood.org/health-topics/sex-101/your-sex-iq-4328.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"NL Holdem Poker IQ Test. (n.d.). testyourpoker.com. Accessed October 10 2026.","url":"https://www.testyourpoker.com/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"American Football IQ. (n.d.). footballiqtest.com. Accessed October 10 2026.","url":"http://www.footballiqtest.com?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Carroll, J.B. (1993). Human cognitive abilities: A survey of factor-analytical studies. New York: Cambridge University Press. ISBN 0-521-38275-0. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","url":"https://en.wikipedia.org/wiki/%20Cambridge_University_Press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Lahn, B.T.; Ebenstein, L. (2009). Let's celebrate human genetic diversity. nature (journal) 461 (7265): 726–728. doi:. PMID 19812654. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Coward, W.M.; Sacket, P.R. (1990). 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Destructive trends in mental health: The well-intentioned path to harm. New York: Taylor and Francis. pp. 155–186. ISBN 0-415-95086-4. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","url":"https://www1.udel.edu/educ/gottfredson/reprints/2005suppressingintelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"@type":"CreativeWork","name":"Gottfredson, L.S. (2006). Social consequences of group differences in cognitive ability (Consequencias sociais das diferencas de grupo em habilidade cognitiva). In Flores-Mendoza, C.E. and Colom, R. (Eds.) (PDF). Introdução à psicologia das diferenças individuais. Porto Alegre, Brazil: ArtMed Publishers. pp. 155–186. ISBN 8-536-30621-1. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. 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J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. p. 15. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-0-19-852367-3?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://archive.org/details/iqhumanintellige00mack?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Internet Archive"}],"url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":2,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-1","text":"Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report.","links":[{"url":"https://www.mun.ca/biology/scarr/APA%201985%20Intelligence%20-%20Knowns%20and%20Unknowns.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Memorial University of Newfoundland — APA report"}],"url":"https://www.mun.ca/biology/scarr/APA%201985%20Intelligence%20-%20Knowns%20and%20Unknowns.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":3,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-2","text":"Johnson, W., Turkheimer, E., Gottesman, I. I., & Bouchard, T. J., Jr. (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18(4), 217–220. doi: 10.1111/j.1467-8721.2009.01639.x. PubMed Central. SAGE Journals. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2899491/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://journals.sagepub.com/doi/10.1111/j.1467-8721.2009.01639.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"},{"url":"https://pubmed.ncbi.nlm.nih.gov/20625474/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2899491/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":4,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-3","text":"Turkheimer, E. (2008, Spring). A Better Way to Use Twins for Developmental Research. LIFE Newsletter, 2–5. Max Planck Institute for Human Development. University of Virginia. Accessed June 29 2010.","links":[{"url":"https://uva.theopenscholar.com/files/eric-turkheimer/files/a_better_way_8.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"University of Virginia"}],"url":"https://uva.theopenscholar.com/files/eric-turkheimer/files/a_better_way_8.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":5,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Devlin97_4","text":"Devlin, B., Daniels, M., & Roeder, K. (1997, July 31). The heritability of IQ. Nature, 388(6641), 468–471. doi: 10.1038/41319. PubMed. Accessed October 10 2026.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/9242404/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed"}],"url":"https://pubmed.ncbi.nlm.nih.gov/9242404/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":6,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-5","text":"Gillham, N. W. (2001). Sir Francis Galton and the birth of eugenics. Annual Review of Genetics, 35, 83-101.","links":[]},{"number":7,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-6","text":"Galton, F. (1865). Hereditary talent and character. Classics in the history of psychology. psychclassics.yorku.ca. Accessed October 10 2026.","links":[{"url":"http://psychclassics.yorku.ca/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psychclassics.yorku.ca"}],"url":"http://psychclassics.yorku.ca/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":8,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-7","text":"Binet, A. (1916). New methods for the diagnosis of the intellectual level of subnormals. In The development of intelligence in children (E. S. Kite, Trans.). Publications of the Training School at Vineland. Original work published 1905. York University — Classics in the History of Psychology. Accessed July 10 2010.","links":[{"url":"https://psychclassics.yorku.ca/Binet/binet1.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"York University — Classics in the History of Psychology"}],"url":"https://psychclassics.yorku.ca/Binet/binet1.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":9,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-8","text":"Wallin, J. E. W. (1911). The new clinical psychology and the psycho-clinicist. Journal of Educational Psychology, 2(4), 191-210.","links":[]},{"number":10,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-9","text":"Spearman, C. (1904). General intelligence. objectively determined and measured. American Journal of Psychology, 15(2), 201-293.","links":[]},{"number":11,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Mayrhauser.2C_R._T._V._1992_10","text":"Mayrhauser, R. T. V. (1992). The mental testing community and validity: A prehistory. American Psychologist, 47(2), 244-253.","links":[]},{"number":12,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-11","text":"Richardson, T. E. (2003). Howard Andrew Knox and the origins of performance testing on Ellis Island, 1212-1216. History of Psychology, 6(2), 143-170.","links":[]},{"number":13,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-12","text":"Terman, L. M., Lyman, G., Ordahl, G., Ordahl, L., Galbreath, N., and Talbert, W. (1915). The Stanford revision of the Binet-Simon scale and some results from its application to 1000 non-selected children. The Journal of Educational Psychology, 6(9), 551-562.","links":[]},{"number":14,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-13","text":"Carmichael, L. (1957). Robert Mearns Yerkes. The Psychological Review, 64(1), 1-7.","links":[]},{"number":15,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Yerkes.2C_R._1919_14","text":"Yerkes, R. (1919). Report of the psychology committee of the national research council. The Psychological Review, 26(2), 83-149.","links":[]},{"number":16,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-15","text":"Driskell, J. E., & Olmstead, B. (1989). Psychology and the military: Research applications and trends. American Psychologist, 44(1), 43-54.","links":[]},{"number":17,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Kevles.2C_D._J._1968_16","text":"Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581.","links":[]},{"number":18,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Keene.2C_J._D._1994_17","text":"Keene, J. D. (1994). Intelligence and morale in the army of a democracy: The genesis of military psychology during the First World War. Military Psychology, 6(4), 235-253.","links":[]},{"number":19,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-18","text":"Kevles, D. J. (1968). Testing the army's intelligence: Psychologists and the military in World War I. The Journal of American History, 55(3), 565-581.","links":[]},{"number":20,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-19","text":"Kennedy, C. H., & McNeil, J. A. (2006). A history of military psychology. In C. H. Kennedy, E. A. Zillmer (Eds.), Military Psychology: Clinical and Operational Applications (pp.1-17). New York: Guilford Publications.","links":[]},{"number":21,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-20","text":"Katzell, R. A., & Austin, J. T. (1992). From then to now: the development of industrial-organizational psychology in the United States. Journal of Applied Psychology. 77(6), 803-835.","links":[]},{"number":22,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-21","text":"Goddard, H. H. (1921). The sub-normal mind versus the abnormal. Journal of Abnormal Psychology, 16(1), 47-54.","links":[]},{"number":23,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Alper.2C_T._G._1944_22","text":"Alper, T. G., & Boring, E. G. (1944). Intelligence-test scores of northern and southern white and negro recruits in 1918. Journal of Abnormal & Social Psychology, 39(4), 471-474.","links":[]},{"number":24,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-23","text":"Thurstone, L. L. (1934). The vectors of mind. Psychological Review, 41, 1-32.","links":[]},{"number":25,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-24","text":"Terman, L. M. (1924). The mental test as a psychological method. The Psychological Review, 31(2), 93-117.","links":[]},{"number":26,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-25","text":"Garrett, H. E. (1945). A note on the intelligence scores of negroes and whites in 1918. Journal of Abnormal & Social Psychology, 40(3), 344-346.","links":[]},{"number":27,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-26","text":"Rembis, M. A. (2004). I ain't been reading while on parole. Experts, mental tests, and eugenic commitment law in Illinois, 1890-1940. History of Psychology, 7(3), 225-247.","links":[]},{"number":28,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#verified-source-370-28","text":"IQ — APA Dictionary of Psychology. (n.d.). American Psychological Association.","links":[{"url":"https://dictionary.apa.org/iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"American Psychological Association"}],"url":"https://dictionary.apa.org/iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":29,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-28","text":"Pinneau, Samuel R. (1961). Changes in Intelligence Quotient Infancy to Maturity: New Insights from the Berkeley Growth Study with Implications for the Stanford-Binet Scales and Applications to Professional Practice. Boston: Houghton Mifflin.","links":[]},{"number":30,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-29","text":"Mussen, Paul Henry. (1973). Psychology: An Introduction. Lexington (MA): Heath. p. 363. ISBN 0-669-61383-7. \"The I.Q. is essentially a rank; there are no true \"units\" of intellectual ability.\". en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-669-61383-7?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":31,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-30","text":"Truch, Steve. (1993). The WISC-III Companion: A Guide to Interpretation and Educational Intervention. Austin (TX): Pro-Ed. p. 35. ISBN 0890795851. \"An IQ score is not an equal-interval score, as is evident in Table A.4 in the WISC-III manual.\". en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0890795851?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":32,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-31","text":"Bartholomew, D. J. (2004). Measuring Intelligence: Facts and Fallacies. Cambridge University Press, p. 50. ISBN 9780521544788. Cambridge University Press.","links":[{"url":"https://www.cambridge.org/core/books/measuring-intelligence/9EFB4DAA867F73021C145B41D3F49015?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Cambridge University Press"}],"url":"https://www.cambridge.org/core/books/measuring-intelligence/9EFB4DAA867F73021C145B41D3F49015?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":33,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-32","text":"Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. pp. 30–31. ISBN 0-19-852367-X. \"In the jargon of psychological measurement theory, IQ is an ordinal scale, where we are simply rank-ordering people. It is not even appropriate to claim that the 10-point difference between IQ scores of 110 and 100 is the same as the 10-point difference between IQs of 160 and 150\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-19-852367-X?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":34,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Perleth_Schatz_M.C3.B6nks_page_301_33","text":"Perleth, Christoph; Schatz, Tanja; Mönks, Franz J. (2000). Early Identification of High Ability. In Heller, Kurt A. Mönks, Franz J. Sternberg, Robert J. et al. International Handbook of Giftedness and Talent (2nd ed.). Amsterdam: Pergamon. p. 301. ISBN 978-0-08-043796-5. \"norm tables that provide you with such extreme values are constructed on the basis of random extrapolation and smoothing but not on the basis of empirical data of representative samples.\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Robert_Sternberg?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-0-08-043796-5?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Robert_Sternberg?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":35,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-34","text":"Terman, Lewis Madison; Merrill, Maude A. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. \"it becomes clear that the probable error of an I.Q. score is not a constant amount, but a variable which increases as I.Q. increases. It has frequently been noted in the literature that gifted subjects show greater I.Q. fluctuation than do clinical cases with low I.Q.'s. we now see that this trend is inherent in the I.Q. technique itself, and might have been predicted on logical grounds.\". en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Lewis_Terman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Lewis_Terman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":36,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-35","text":"Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. ISBN 0-13-236273-2. \"obtained scores tend to underestimate universe scores for the bottom half of the distribution and overestimate universe scores for the top half of the distribution\". en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Prentice_Hall?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-13-236273-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Prentice_Hall?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":37,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-36","text":"Hopkins, Kenneth D.; Stanley, Julian C. (1981). Educational and Psychological Measurement and Evaluation. (sixth ed.). Engelwood Cliffs (NJ): Prentice Hall. p. 346. ISBN 0-13-236273-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Prentice_Hall?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-13-236273-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Prentice_Hall?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":38,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-37","text":"Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Alan_S._Kaufman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-0-8261-0629-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Alan_S._Kaufman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":39,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-38","text":"Terman, Lewis Madison; Merrill, MaudeA. (1937). Measuring intelligence: A guide to the administration of the new revised Stanford-Binet tests of intelligence. Riverside textbooks in education. Boston (MA): Houghton Mifflin. p. 44. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Lewis_Terman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Lewis_Terman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":40,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-39","text":"Anastasi, A., & Urbina, S. (1997). Psychological Testing. 7th ed., pp. 326–327. Prentice Hall. ISBN 9780023030857. Pearson. Accessed October 10 2026.","links":[{"url":"https://www.pearson.com/en-us/subject-catalog/p/redirected-product/P200000002697/9780023030857?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Pearson"}],"url":"https://www.pearson.com/en-us/subject-catalog/p/redirected-product/P200000002697/9780023030857?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":41,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-40","text":"Kaufman, Alan S. (2009). IQ Testing 101. New York: Springer Publishing. pp. 151–153. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Alan_S._Kaufman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-0-8261-0629-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Alan_S._Kaufman?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":42,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Neisser97_41","text":"Neisser U. (1997). Rising Scores on Intelligence Tests. American Scientist 85: 440–7. americanscientist.org.","links":[{"url":"https://www.americanscientist.org/issues/feature/rising-scores-on-intelligence-tests/1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"americanscientist.org"}],"url":"https://www.americanscientist.org/issues/feature/rising-scores-on-intelligence-tests/1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":43,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Neisser1998_42","text":"Neisser, Ulric, ed. (1998). The Rising Curve: Long-Term Gains in IQ and Related Measures. APA Science Volume Series. Washington (DC): American Psychological Association. ISBN 978-1-55798-503-3. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-1-55798-503-3?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":44,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Mackintosh1998_43","text":"Mackintosh, N. J. (1998). IQ and Human Intelligence. Oxford: Oxford University Press. ISBN 978-0-19-852367-3. Lay summary (9 August 2010). en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Internet Archive.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-0-19-852367-3?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://archive.org/details/iqhumanintellige00mack?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Internet Archive"}],"url":"https://en.wikipedia.org/wiki/%20Nicholas_Mackintosh?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":45,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Flynn2009_44","text":"Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.","links":[{"url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Bactra — book review"}],"url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":46,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Flynn1984_45","text":"Flynn, James R. title=The Mean IQ of Americans: Massive Gains 1932 to 1978. (1984). Psychological Bulletin. 95: 29–51. doi. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Psychological_Bulletin?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.95.1.29&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"}],"url":"https://en.wikipedia.org/wiki/%20Psychological_Bulletin?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":47,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Flynn1987_46","text":"Flynn, James R. (1987, March). Massive IQ Gains in 14 Nations: What IQ Tests Really Measure. Psychological Bulletin 101 (2): 171–191. doi:. American Psychological Association. psycnet.apa.org:443. en.wikipedia.org. psycnet.apa.org:443. psycnet.apa.org:443. Accessed August 22 2010.","links":[{"url":"https://psycnet.apa.org:443/index.cfm?fa=buy.optionToBuy&id=2008-10701-001&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"},{"url":"https://en.wikipedia.org/wiki/%20Psychological_Bulletin?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.101.2.171&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"},{"url":"https://psycnet.apa.org:443/index.cfm?fa=buy.optionToBuy&id=2008-10701-002&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"}],"url":"https://psycnet.apa.org:443/index.cfm?fa=buy.optionToBuy&id=2008-10701-001&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":48,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-ZhouGr.C3.A9goireZhu2010_47","text":"Zhou, X., Grégoire, J., & Zhu, J. (2010). The Flynn Effect and the Wechsler Scales. In L. G. Weiss, D. H. Saklofske, D. Coalson, et al. (Eds.), WAIS-IV clinical use and interpretation: Scientist-practitioner perspectives. Academic Press. ISBN 9780123750358. ScienceDirect.","links":[{"url":"https://www.sciencedirect.com/science/chapter/edited-volume/pii/B9780123750358100059?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com#description","label":"ScienceDirect"}],"url":"https://www.sciencedirect.com/science/chapter/edited-volume/pii/B9780123750358100059?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com#description"},{"number":49,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-48","text":"Qian M, Wang D, Watkins WE, et al. (2005). The effects of iodine on intelligence in children: a meta-analysis of studies conducted in China. Asia Pacific Journal of Clinical Nutrition 14 (1): 32–42. PMID 15734706. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.","links":[{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15734706/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":50,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-49","text":"Gene governs IQ boost from breastfeeding. (n.d.). physorg.com. Accessed October 10 2026.","links":[{"url":"https://medicalxpress.com/news/2007-11-gene-iq-boost-breastfeeding.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"physorg.com"}],"url":"https://medicalxpress.com/news/2007-11-gene-iq-boost-breastfeeding.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":51,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-pmid17984066_50","text":"Caspi, A., Williams, B., Kim-Cohen, J., Craig, I. W., Milne, B. J., Poulton, R., Schalkwyk, L. C., Taylor, A., Werts, H., & Moffitt, T. E. (2007). Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism. Proceedings of the National Academy of Sciences, 104(47), 18860–18865. doi: 10.1073/pnas.0704292104. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2141867/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://pnas.org/doi/full/10.1073/pnas.0704292104?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Proceedings of the National Academy of Sciences"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17984066/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2141867/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":52,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-51","text":"Schellenberg, E. G. (2004). Music lessons enhance IQ. Psychol Sci 15(8): 511-4.","links":[]},{"number":53,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-52","text":"(Klingberg et al., 2002). (n.d.).","links":[]},{"number":54,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-53","text":"Jaeggi SM, Buschkuehl M, Jonides J, Perrig WJ. (2008). Improving fluid intelligence with training on working memory. Proc. Natl. Acad. Sci. U.S.A. 105 (19): 6829–6833. doi:. PMID 18443283. PMC 2383929. pnas.org. pnas.org. en.wikipedia.org. National Library of Medicine. en.wikipedia.org. PubMed Central. Accessed October 10 2026.","links":[{"url":"https://www.pnas.org/cgi/content/abstract/0801268105v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"pnas.org"},{"url":"https://pnas.org/doi/full/10.1073/pnas.0801268105?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"pnas.org"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/18443283/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Central?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383929/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"}],"url":"https://www.pnas.org/cgi/content/abstract/0801268105v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":55,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Plomin0103_54","text":"Plomin et al. (2001, 2003).","links":[]},{"number":56,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-55","text":"Harris. (1998).","links":[]},{"number":57,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-56","text":"Bouchard TJ. (1998). Genetic and environmental influences on adult intelligence and special mental abilities. Hum. Biol. 70 (2): 257–279. PMID 9549239. en.wikipedia.org. National Library of Medicine. Accessed June 29 2010.","links":[{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/9549239/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":58,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Stoolmiller99_57","text":"Stoolmiller, M. (1999). Implications of the restricted range of family environments for estimates of heritability and nonshared environment in behavior-genetic adoption studies. Psychological Bulletin, 125(4), 392–409. doi: 10.1037/0033-2909.125.4.392. PubMed. APA PsycNet.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/10414224/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed"},{"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.125.4.392&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"APA PsycNet"}],"url":"https://pubmed.ncbi.nlm.nih.gov/10414224/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":59,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-McGue_58","text":"McGue, M. et al. (2007). The Environments of Adopted and Non-adopted Youth: Evidence on Range Restriction From the Sibling Interaction and Behavior Study (SIBS). Behavior Genetics 37 (3): 449. doi:. PMID 17279339. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://link.springer.com/article/10.1007/s10519-007-9142-7?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17279339/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://link.springer.com/article/10.1007/s10519-007-9142-7?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":60,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-59","text":"Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychol Sci 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/14629696/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":61,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-60","text":"Socioeconomic status modifies heritability of iq in young children Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, Irving I. (2003). Gottesman. Psychological Science 14 (6), 623–628. 2003. blackwell-synergy.com.","links":[{"url":"https://onlinelibrary.wiley.com/doi/abs/10.1046/j.0956-7976.2003.psci_1475.x?cookieSet=1&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"blackwell-synergy.com"}],"url":"https://onlinelibrary.wiley.com/doi/abs/10.1046/j.0956-7976.2003.psci_1475.x?cookieSet=1&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":63,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Bouchard02_62","text":"Bouchard, T.J.; McGue, M. (2003). Genetic and environmental influences on human psychological differences. Journal of Neurobiology 54 (1): 4. doi:. PMID 12486697. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://onlinelibrary.wiley.com/doi/10.1002/neu.10160?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Wiley"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/12486697/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://onlinelibrary.wiley.com/doi/10.1002/neu.10160?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":64,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-DickensFlynn2001_63","text":"Dickens and Flynn. (2001).","links":[]},{"number":65,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-64","text":"Dickens, W. T., & Flynn, J. R. (2002). The IQ Paradox: Still Resolved. Psychological Review, 109(4). Brookings Institution.","links":[{"url":"https://www.brookings.edu/wp-content/uploads/2016/06/20020205-1.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Brookings Institution"}],"url":"https://www.brookings.edu/wp-content/uploads/2016/06/20020205-1.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":66,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-65","text":"Plomin R, Pedersen NL, Lichtenstein P, McClearn GE. (1994, May). Variability and stability in cognitive abilities are largely genetic later in life. Behavior Genetics 24 (3): 207–15. doi:. PMID 7945151. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://link.springer.com/article/10.1007/BF01067188?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/7945151/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://link.springer.com/article/10.1007/BF01067188?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":67,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Neisser95_66","text":"Neisser et al. (1995, August 7). Intelligence: Knowns and Unknowns. Board of Scientific Affairs of the American Psychological Association. webspace.ship.edu. en.wikipedia.org. Accessed October 10 2026.","links":[{"url":"https://webspace.ship.edu/cgboer/iku.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"webspace.ship.edu"},{"url":"https://en.wikipedia.org/wiki/%20American_Psychological_Association?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://webspace.ship.edu/cgboer/iku.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":68,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-67","text":"Bouchard TJ, Lykken DT, McGue M, Segal NL, Tellegen A. (1990). Sources of human psychological differences: the Minnesota Study of Twins Reared Apart. Science 250 (4978): 223–228. doi:. PMID 2218526. sciencemag.org. science.org. en.wikipedia.org. National Library of Medicine.","links":[{"url":"http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=2218526&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"sciencemag.org"},{"url":"https://www.science.org/doi/10.1126/science.2218526?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"science.org"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/2218526/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=2218526&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":69,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-freese_68","text":"Commentary: The analysis of variance and the social complexities of genetic causation. (2006). by Jeremy Freese International Journal of Epidemiology 35(3):534-536. Oxford Academic.","links":[{"url":"https://academic.oup.com/ije/article/35/3/534/735803/Commentary-The-analysis-of-variance-and-the-social?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Oxford Academic"}],"url":"https://academic.oup.com/ije/article/35/3/534/735803/Commentary-The-analysis-of-variance-and-the-social?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":70,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-rose_69","text":"Commentary: Heritability estimates—long past their sell-by date. (2006). by Steven P R Rose Int. J. Epidemiol. 35: 525-527. Oxford Academic.","links":[{"url":"https://academic.oup.com/ije/article/35/3/525/735798/Commentary-Heritability-estimateslong-past-their?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Oxford Academic"}],"url":"https://academic.oup.com/ije/article/35/3/525/735798/Commentary-Heritability-estimateslong-past-their?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":71,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-taylor_70","text":"Commentary: The analysis of variance is an analysis of causes (of a very circumscribed kind). (2006). Int. J. Epidemiol. 35: 527-531. Oxford Academic.","links":[{"url":"https://academic.oup.com/ije/article/35/3/527/735793/Commentary-The-analysis-of-variance-is-an-analysis?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Oxford Academic"}],"url":"https://academic.oup.com/ije/article/35/3/527/735793/Commentary-The-analysis-of-variance-is-an-analysis?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":72,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Vreeke_71","text":"Commentary: The attainability of causal knowledge of genetic effects in complex human traits. (2006). Int. J. Epidemiol. 35: 531-534. Oxford Academic.","links":[{"url":"https://academic.oup.com/ije/article/35/3/531/735806/Commentary-The-attainability-of-causal-knowledge?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Oxford Academic"}],"url":"https://academic.oup.com/ije/article/35/3/531/735806/Commentary-The-attainability-of-causal-knowledge?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":73,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-lewontin_72","text":"Commentary: Statistical analysis or biological analysis as tools for understanding biological causes. (2006). Int. J. Epidemiol. '35:' 536-537. Oxford Academic.","links":[{"url":"https://academic.oup.com/ije/article/35/3/536/735821/Commentary-Statistical-analysis-or-biological?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Oxford Academic"}],"url":"https://academic.oup.com/ije/article/35/3/536/735821/Commentary-Statistical-analysis-or-biological?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":74,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-lewontin_2_73","text":"The analysis of variance and the analysis of causes. (2006). Int. J. Epidemiol. 35: 520-525. Oxford Academic.","links":[{"url":"https://academic.oup.com/ije/article/35/3/520/735787/The-analysis-of-variance-and-the-analysis-of?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Oxford Academic"}],"url":"https://academic.oup.com/ije/article/35/3/520/735787/The-analysis-of-variance-and-the-analysis-of?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":75,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-74","text":"Turkheimer E, Haley A, Waldron M, D'Onofrio B, Gottesman II. (2003, November). Socioeconomic status modifies heritability of IQ in young children. Psychological Science 14 (6): 623–8. doi:. PMID 14629696. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/14629696/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://journals.sagepub.com/doi/10.1046/j.0956-7976.2003.psci_1475.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":76,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-TJ_75","text":"Bouchard, TJ. (2004). Genetic influence on human psychological traits - A survey. Current Directions in Psychological Science 13 (4): 148–151. doi. SAGE Journals. Accessed October 10 2026.","links":[{"url":"https://journals.sagepub.com/doi/10.1111/j.0963-7214.2004.00295.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"}],"url":"https://journals.sagepub.com/doi/10.1111/j.0963-7214.2004.00295.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":77,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-76","text":"See: Ethnic Differences in Children's Intelligence Test Scores: Role of Economic Deprivation, Home Environment, and Maternal Characteristics. (n.d.).","links":[]},{"number":78,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-77","text":"Brain Research Institute, UC Irvine College of Medicine. (n.d.). Human Intelligence Determined by Volume and Location of Gray Matter Tissue in Brain. Brain Research Institute, UC Irvine College of Medicine. sciencedaily.com. Accessed October 10 2026.","links":[{"url":"https://www.sciencedaily.com/releases/2004/07/040720090419.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"sciencedaily.com"}],"url":"https://www.sciencedaily.com/releases/2004/07/040720090419.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":79,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-78","text":"Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.","links":[{"url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"discovery.ucl.ac.uk"}],"url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":80,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-79","text":"Shaw P, Greenstein D, Lerch J, et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://www.nature.com/articles/nature04513?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/16572172/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.nature.com/articles/nature04513?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":81,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-80","text":"Wade, N. (2006). Scans Show Different Growth for Intelligent Brains. The New York Times. The New York Times. Accessed August 6 2006.","links":[{"url":"https://www.nytimes.com/2006/03/30/science/30brain.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"The New York Times"}],"url":"https://www.nytimes.com/2006/03/30/science/30brain.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":83,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-82","text":"Gosso MF, van Belzen M, de Geus EJ, et al. (2006). Association between the CHRM2 gene and intelligence in a sample of 304 Dutch families. Genes, Brain and Behavior 5 (8): 577–584. doi:. PMID 17081262. en.wikipedia.org. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Genes,_Brain_and_Behavior?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://onlinelibrary.wiley.com/doi/10.1111/j.1601-183X.2006.00211.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Wiley"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17081262/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Genes,_Brain_and_Behavior?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":84,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-83","text":"Dick DM, Aliev F, Kramer J, et al. (2007). Association of CHRM2 with IQ: converging evidence for a gene influencing intelligence. Behav. Genet. 37 (2): 265–272. doi:. PMID 17160701. Springer. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://link.springer.com/article/10.1007/s10519-006-9131-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17160701/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://link.springer.com/article/10.1007/s10519-006-9131-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":85,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-84","text":"Bava, S., Ballantyne, A. O., & Trauner, D. A. (2005). Disparity of verbal and performance IQ following early bilateral brain damage. Cognitive and Behavioral Neurology, 18(3), 163–170. doi: 10.1097/01.wnn.0000178228.61938.3e. PubMed. Ovid. Accessed October 10 2026.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/16175020/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed"},{"url":"https://www.ovid.com/jnls/cogbehavneurol/abstract/10.1097/01.wnn.0000178228.61938.3e~disparity-of-verbal-and-performance-iq-following-early?redirectionsource=fulltextview&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Ovid"}],"url":"https://pubmed.ncbi.nlm.nih.gov/16175020/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":86,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-85","text":"Reed, T.E., & Jensen, A.R. (1993). Cranial capacity: new Caucasian data and comments on Rushton's claimed Mongoloid-Caucasoid brain-size differences. Intelligence, 17, 423-431.","links":[]},{"number":87,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-86","text":"McDaniel, M. A. (2005). Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence. Intelligence, 33, 337–346. ScienceDirect.","links":[{"url":"https://www.sciencedirect.com/science/article/pii/S0160289604001357?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"ScienceDirect"}],"url":"https://www.sciencedirect.com/science/article/pii/S0160289604001357?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":88,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-87","text":"Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, pp. 220–222. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.","links":[{"url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer Publishing"}],"url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":89,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Okanoya_88","text":"Okanoya K, Tokimoto N, Kumazawa N, Hihara S, Iriki A. (2008). Tool-use training in a species of rodent: the emergence of an optimal motor strategy and functional understanding. PLoS ONE 3 (3): e1860. doi:. PMID 18365015. PubMed Central. PLOS. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2268009/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0001860&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PLOS"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/18365015/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2268009/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":90,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-89","text":"Jaeggi, S. M., Buschkuehl, M., Jonides, J., & Perrig, W. J. (2008). Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences, 105(19), 6829–6833. doi: 10.1073/pnas.0801268105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383929/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://pnas.org/doi/full/10.1073/pnas.0801268105?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Proceedings of the National Academy of Sciences"},{"url":"https://pubmed.ncbi.nlm.nih.gov/18443283/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383929/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":91,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-90","text":"Sternberg, R. J. (2008). Increasing fluid intelligence is possible after all. Proceedings of the National Academy of Sciences, 105(19), 6791–6792. doi: 10.1073/pnas.0803396105. PubMed Central. Proceedings of the National Academy of Sciences. National Library of Medicine.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383939/","label":"PubMed Central"},{"url":"https://pnas.org/doi/full/10.1073/pnas.0803396105?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Proceedings of the National Academy of Sciences"},{"url":"https://pubmed.ncbi.nlm.nih.gov/18474863/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC2383939/"},{"number":92,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-91","text":"McArdle J J, Ferrer-Caja E, Hamagami F, Woodcock RW. (2002). Comparative longitudinal structural analyses of the growth and decline of multiple intellectual abilities over the life span. Dev. Psychol. 38: 115–142. PMID 11806695 Based on a sample of 1200 US individuals aged 2–95 years representative of both genders of major ethnic groups and all education levels. National Library of Medicine.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/11806695/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pubmed.ncbi.nlm.nih.gov/11806695/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":93,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Breslau_92","text":"Breslau N, Lucia VC, Alvarado GF. (2006). Intelligence and other predisposing factors in exposure to trauma and posttraumatic stress disorder: a follow-up study at age 17 years. Arch. Gen. Psychiatry 63 (11): 1238–1245. doi:. PMID 17088504. JAMA Network. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://jamanetwork.com/article.aspx?doi=10.1001%2Farchpsyc.63.11.1238&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"JAMA Network"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17088504/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://jamanetwork.com/article.aspx?doi=10.1001%2Farchpsyc.63.11.1238&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":94,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-93","text":"Zinkstok, J. R., de Wilde, O., van Amelsvoort, T. A. M. J., Tanck, M. W., Baas, F., & Linszen, D. H. (2007). Association between the DTNBP1 gene and intelligence: a case-control study in young patients with schizophrenia and related disorders and unaffected siblings. Behavioral and Brain Functions, 3, 19. doi: 10.1186/1744-9081-3-19. PubMed Central. Springer. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1864987/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://link.springer.com/article/10.1186/1744-9081-3-19?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17445278/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1864987/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":95,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-94","text":"Woodberry KA, Giuliano AJ, Seidman LJ. (2008). Premorbid IQ in schizophrenia: a meta-analytic review. Am J Psychiatry 165 (5): 579–587. doi:. PMID 18413704. PsychiatryOnline. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://psychiatryonline.org/doi/10.1176/appi.ajp.2008.07081242?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PsychiatryOnline"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/18413704/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://psychiatryonline.org/doi/10.1176/appi.ajp.2008.07081242?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":96,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-95","text":"Sackeim HA, Freeman J, McElhiney M, Coleman E, Prudic J, Devanand DP. (1992). Effects of major depression on estimates of intelligence. J Clin Exp Neuropsychol 14 (2): 268–288. doi:. PMID 1572949. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://www.tandfonline.com/doi/full/10.1080/01688639208402828?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Taylor & Francis"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/1572949/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.tandfonline.com/doi/full/10.1080/01688639208402828?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":97,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Mandelli_96","text":"Mandelli L, Serretti A, Colombo C, et al. (2006). Improvement of cognitive functioning in mood disorder patients with depressive symptomatic recovery during treatment: an exploratory analysis. Psychiatry Clin. Neurosci. 60 (5): 598–604. doi:. PMID 16958944. blackwell-synergy.com. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1819.2006.01564.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"blackwell-synergy.com"},{"url":"https://onlinelibrary.wiley.com/doi/10.1111/j.1440-1819.2006.01564.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Wiley"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/16958944/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1819.2006.01564.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":98,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-97","text":"Debbie A. Lawlor, University of Bristol, Heather Clark, University of Aberdeen, David A. Leon, London School of Hygiene & Tropical Medicine. (2006). Associations Between Childhood Intelligence and Hospital Admissions for Unintentional Injuries in Adulthood: The Aberdeen Children of the 1950s Cohort Study. American Journal of Public Health, December 2006. ajph.org. Accessed January 10 2007.","links":[{"url":"https://www.ajph.org/cgi/content/abstract/AJPH.2005.080168v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"ajph.org"}],"url":"https://www.ajph.org/cgi/content/abstract/AJPH.2005.080168v1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":99,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Whalley_98","text":"Whalley, L. J., & Deary, I. J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. BMJ, 322(7290), 819. doi: 10.1136/bmj.322.7290.819. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC30556/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://www.bmj.com/content/322/7290/819?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"BMJ"},{"url":"https://pubmed.ncbi.nlm.nih.gov/11290633/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC30556/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":100,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-99","text":"Cervilla, J., Prince, M., Joels, S., Lovestone, S., & Mann, A. (2004, August). Premorbid cognitive testing predicts the onset of dementia and Alzheimer's disease better than and independently of APOE genotype. Journal of Neurology, Neurosurgery & Psychiatry, 75(8), 1100–1106. doi: 10.1136/jnnp.2003.028076. PubMed Central. BMJ. National Library of Medicine.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1739178/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"},{"url":"https://jnnp.bmj.com/lookup/doi/10.1136/jnnp.2003.028076?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"BMJ"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15258208/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1739178/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":101,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-100","text":"American Psychological Association. (2004, January 4). More sensitive test norms better predict which high IQ adults might develop Alzheimer's. Press release. American Psychological Association. American Psychological Association. Accessed August 6 2006.","links":[{"url":"https://www.apa.org/news/press/releases/2004/01/alzheimers-iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"American Psychological Association"}],"url":"https://www.apa.org/news/press/releases/2004/01/alzheimers-iq?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":102,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Whalley00_101","text":"Whalley LJ, Starr JM, Athawes R, Hunter D, Pattie A, Deary IJ. (2000). Childhood mental ability and dementia. Neurology 55 (10): 1455–1459. PMID 11094097. neurology.org. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://www.neurology.org/cgi/pmidlookup?view=long&pmid=11094097&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"neurology.org"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/11094097/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.neurology.org/cgi/pmidlookup?view=long&pmid=11094097&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":103,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Olness_102","text":"World Health Organization. (n.d.). Lead poisoning. WHO. World Health Organization. Accessed October 10 2026.","links":[{"url":"https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"World Health Organization"}],"url":"https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":104,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-103","text":"Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/","label":"PubMed Central"},{"url":"https://www.bmj.com/content/334/7587/245?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"BMJ"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17175567/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/"},{"number":105,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-104","text":"Taylor, MD; Hart, Carole L.; Smith, George Davey; Starr, John M.; Hole, David J.; Whalley, Lawrence J.; Wilson, Valerie; Deary, Ian J. (2005). Childhood IQ and social factors on smoking behaviour, lung function and smoking-related outcomes in adulthood: linking the Scottish Mental Survey 1932 and the Midspan studies. British Journal of Health Psychology 10 (3): 399–401. doi:. PMID 16238855. Wiley. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://bpspsychub.onlinelibrary.wiley.com/doi/10.1348/135910705X25075?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Wiley"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/16238855/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://bpspsychub.onlinelibrary.wiley.com/doi/10.1348/135910705X25075?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":106,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-105","text":"Frey MC, Detterman DK. (2004, June). Scholastic Assessment or g? The relationship between the Scholastic Assessment Test and general cognitive ability. Psychological Science 15 (6): 373–8. doi:. PMID 15147489. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://journals.sagepub.com/doi/10.1111/j.0956-7976.2004.00687.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15147489/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://journals.sagepub.com/doi/10.1111/j.0956-7976.2004.00687.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":107,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Deary2007_106","text":"Ritchie, S. J., & Tucker-Drob, E. M. (2018). How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 29(8), 1358–1369. labs.la.utexas.edu. Accessed October 10 2026.","links":[{"url":"https://labs.la.utexas.edu/tucker-drob/files/2019/08/Ritchie-Tucker-Drob-2018-Psych-Science-How-Much-Does-Education-Improve-Intelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"labs.la.utexas.edu"}],"url":"https://labs.la.utexas.edu/tucker-drob/files/2019/08/Ritchie-Tucker-Drob-2018-Psych-Science-How-Much-Does-Education-Improve-Intelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":108,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Schmidt98_107","text":"Schmidt, Frank L.; Hunter, John E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin 124: 262. doi. psycnet.apa.org:443.","links":[{"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.124.2.262&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"}],"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0033-2909.124.2.262&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":109,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Hunter84_108","text":"Hunter, J. E. and Hunter, R. F. (1984). Validity and utility of alternative predictors of job performance. Psychological Bulletin, 96, 72–98.","links":[]},{"number":110,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-109","text":"Warner MH, Ernst J, Townes BD, Peel J, Preston M. (1987). Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R. J Clin Exp Neuropsychol 9 (5): 545–562. doi:. PMID 3667899. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://www.tandfonline.com/doi/full/10.1080/01688638708410768?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Taylor & Francis"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/3667899/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.tandfonline.com/doi/full/10.1080/01688638708410768?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":111,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-110","text":"Marley W. Watkins, Pui-Wa Lei and Gary L. Canivez. (2007). Psychometric intelligence and achievement: A cross-lagged panel analysis, Intelligence, 35, 59-68.","links":[]},{"number":112,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-111","text":"Treena Eileen Rohde and Lee Anne Thompson. (2007). Predicting academic achievement with cognitive ability, Intelligence, 35, 83-92.","links":[]},{"number":113,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-112","text":"Detterman and Daniel, 1989. (n.d.).","links":[]},{"number":114,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-113","text":"Hunt, E. (1995, July–August). The role of intelligence in modern society. American Scientist, section: Nonlinearities in Intelligence. Archived May 21, 2006. Internet Archive. americanscientist.org. Accessed October 10 2026.","links":[{"url":"https://web.archive.org/web/20060521185816/http://www.americanscientist.org/template/AssetDetail/assetid/24538/page/4?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Internet Archive"},{"url":"https://www.americanscientist.org/template/AssetDetail/assetid/24538/page/4?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"americanscientist.org"}],"url":"https://web.archive.org/web/20060521185816/http://www.americanscientist.org/template/AssetDetail/assetid/24538/page/4?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":115,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-114","text":"Coward, W.M. and Sackett, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology, 75:297–300.","links":[]},{"number":116,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-115","text":"Murray, Charles. (1998). Income Inequality and IQ, AEI Press PDF. aei.org. Accessed October 10 2026.","links":[{"url":"https://www.aei.org/wp-content/uploads/2011/10/20040302_book443.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"aei.org"}],"url":"https://www.aei.org/wp-content/uploads/2011/10/20040302_book443.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":117,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-116","text":"Henderson, M. (2007, April 25). Brains don't make you rich, IQ study finds. The Times (London). Accessed May 5 2010. Original online source unavailable.","links":[]},{"number":118,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-117","text":"Bowles, S., & Gintis, H. (2002). The inheritance of inequality. Journal of Economic Perspectives, 16(3), 3–30. doi: 10.1257/089533002760278686. American Economic Association.","links":[{"url":"https://www.aeaweb.org/articles?id=10.1257/089533002760278686&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"American Economic Association"}],"url":"https://www.aeaweb.org/articles?id=10.1257/089533002760278686&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":119,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-118","text":"McDaniel, M. A. (2006). Estimating state IQ: Measurement challenges and preliminary correlates. Intelligence, 34(6), 607–619. doi: 10.1016/j.intell.2006.08.007. ScienceDirect.","links":[{"url":"https://www.sciencedirect.com/science/article/pii/S0160289606001061?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"ScienceDirect"}],"url":"https://www.sciencedirect.com/science/article/pii/S0160289606001061?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":120,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-119","text":"Tambs K, Sundet JM, Magnus P, Berg K. (1989). Genetic and environmental contributions to the covariance between occupational status, educational attainment, and IQ: a study of twins. Behav Genet. 1989 Mar;19(2):209–22. PMID 2719624. National Library of Medicine.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/2719624/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pubmed.ncbi.nlm.nih.gov/2719624/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":121,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-120","text":"Rowe, D. C., W. J. Vesterdal, and J. L. Rodgers. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. University of Arizona, 1997.","links":[]},{"number":122,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-Nyborg_121","text":"Dürlinger, F., & Pietschnig, J. (2022). Meta-analyzing intelligence and religiosity associations: Evidence from the multiverse. PLOS ONE, 17(2), e0262699. PLOS. Accessed October 10 2026.","links":[{"url":"https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0262699&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PLOS"}],"url":"https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0262699&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":123,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-122","text":"Douglas N. (2006). Jackson and J. Philippe Rushton, Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test, Intelligence, Volume 34, Issue 5, September–October 2006, Pages 479-486.","links":[]},{"number":124,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-123","text":"Lynn, R., & Irwing, P. (2004). Sex differences on the Progressive Matrices: A meta-analysis. Intelligence, 32, 481-498.","links":[]},{"number":125,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-124","text":"Deary, I.J., Irwing, P., Der, G., & Bates, T.C. (2007). Brother–sister differences in the g factor in intelligence: Analysis of full, opposite-sex siblings from the NLSY1979. Intelligence, 35(5): 451-456.","links":[]},{"number":126,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-125","text":"Biswas-Diener, R. (n.d.). Intelligence. Noba. nobaproject.com. Accessed October 10 2026.","links":[{"url":"https://nobaproject.com/modules/intelligence?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"nobaproject.com"}],"url":"https://nobaproject.com/modules/intelligence?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":127,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-126","text":"Publications. (n.d.). rlynn.co.uk. Accessed October 10 2026.","links":[{"url":"http://www.rlynn.co.uk/index.php?page=publications&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"rlynn.co.uk"}],"url":"http://www.rlynn.co.uk/index.php?page=publications&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":128,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-127","text":"Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, p. 173. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.","links":[{"url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer Publishing"}],"url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":129,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-128","text":"Brody, Nathan chapter=To g or Not to g—That Is the Question. (2005). Wilhelm, Oliver & Engle, Randall W. (Eds.). ed. Handbook of Understanding and Measuring Intelligence. Thousand Oaks (CA): SAGE Publications. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20SAGE_Publications?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20SAGE_Publications?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":130,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-129","text":"Bernie Devlin, Stephen E. Fienberg, Daniel P. Resnick & Kathryn Roeder, ed. (1997). Intelligence, Genes, and Success: Scientists Respond to the Bell Curve. New York (NY): Springer Verlag. ISBN 0-38798234-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Springer_Science%2BBusiness_Media?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-38798234-5?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Springer_Science%2BBusiness_Media?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":131,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-130","text":"Nisbett, R. E. (2009). Intelligence and How to Get It: Why Schools and Cultures Count. W. W. Norton. ISBN 9780393065053. W. W. Norton.","links":[{"url":"https://wwnorton.com/books/9780393065053?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"W. W. Norton"}],"url":"https://wwnorton.com/books/9780393065053?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":132,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-131","text":"Kaufman, A. S. (2009). IQ Testing 101. Springer Publishing, Chapter 8. ISBN 9780826106292. Springer Publishing. Accessed October 10 2026.","links":[{"url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer Publishing"}],"url":"https://www.springerpub.com/all-products/iq-testing-101-9780826106292.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":133,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-132","text":"[Referenced web resource]. (n.d.). (PDF). rand.org. Accessed October 10 2026.","links":[{"url":"https://www.rand.org/content/dam/rand/pubs/technical_reports/2005/RAND_TR193.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"rand.org"}],"url":"https://www.rand.org/content/dam/rand/pubs/technical_reports/2005/RAND_TR193.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":134,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-133","text":"Kilburn, M. R., Hanser, L. M., & Klerman, J. A. (1998). Estimating AFQT scores for National Educational Longitudinal Study (NELS) respondents. RAND Corporation, report MR-818-OSD/A, Chapter 2. RAND Corporation.","links":[{"url":"https://www.rand.org/content/dam/rand/pubs/monograph_reports/2009/MR818.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"RAND Corporation"}],"url":"https://www.rand.org/content/dam/rand/pubs/monograph_reports/2009/MR818.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":135,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-134","text":"Social Security Administration. (n.d.). ssa.gov. Accessed October 10 2026.","links":[{"url":"https://www.ssa.gov/disability/professionals/bluebook/12.00-MentalDisorders-Adult.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"ssa.gov"}],"url":"https://www.ssa.gov/disability/professionals/bluebook/12.00-MentalDisorders-Adult.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":136,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-135","text":"Flynn, J. R. (2009). What Is Intelligence: Beyond the Flynn Effect. Expanded paperback ed. Cambridge University Press. ISBN 9780521741477. Bactra — book review.","links":[{"url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Bactra — book review"}],"url":"https://bactra.org/reviews/flynn-beyond/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":137,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-136","text":"Lemann, N. (1999, March 29). The IQ meritocracy. TIME. TIME.","links":[{"url":"https://time.com/archive/6735029/the-iq-meritocracy/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"TIME"}],"url":"https://time.com/archive/6735029/the-iq-meritocracy/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":139,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-138","text":"Davis, B. D. (1983, Fall). Neo-Lysenkoism, IQ, and the press. The Public Interest, 73, 41–59. National Affairs — The Public Interest archive.","links":[{"url":"https://nationalaffairs.com/public_interest/detail/neo-lysenkoism-iq-and-the-press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Affairs — The Public Interest archive"}],"url":"https://nationalaffairs.com/public_interest/detail/neo-lysenkoism-iq-and-the-press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":140,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-www2.psych.purdue.edu_139","text":"Models and muddles of heritability. (n.d.). Genetica, 99, 97-108. PubMed.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/9463078/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed"}],"url":"https://pubmed.ncbi.nlm.nih.gov/9463078/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":141,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-140","text":"Schönemann, P. H. (1983). Do IQ tests really measure intelligence? Commentary, The Behavioral and Brain Sciences, 6, 311-313.","links":[]},{"number":142,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-141","text":"The Waning of I.Q. (n.d.). by David Brooks, The New York Times. The New York Times. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","links":[{"url":"http://select.nytimes.com/2007/09/14/opinion/14brooks.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"The New York Times"},{"url":"https://en.wikipedia.org/wiki/%20David_Brooks_(journalist)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20The_New_York_Times?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"http://select.nytimes.com/2007/09/14/opinion/14brooks.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":143,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-142","text":"Verney, S. P., Granholm, E., Marshall, S. P., Malcarne, V. L., & Saccuzzo, D. P. (2005). Culture-fair cognitive ability assessment: Information processing and psychophysiological approaches. Assessment, 12(3), 303–319. doi: 10.1177/1073191105276674. PubMed.","links":[{"url":"https://pubmed.ncbi.nlm.nih.gov/16123251/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed"}],"url":"https://pubmed.ncbi.nlm.nih.gov/16123251/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":144,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-143","text":"Shuttleworth-Edwards AB, Kemp RD, Rust AL, Muirhead JG, Hartman NP, Radloff SE. (2004). Cross-cultural effects on IQ test performance: a review and preliminary normative indications on WAIS-III test performance. J Clin Exp Neuropsychol 26 (7): 903–920. doi:. PMID 15742541. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://www.tandfonline.com/doi/full/10.1080/13803390490510824?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Taylor & Francis"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15742541/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.tandfonline.com/doi/full/10.1080/13803390490510824?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":145,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-144","text":"Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons. (2004). 1*, Leah K. Hamilton1, Betty R. Onyura1 and Andrew S. Winston International Journal of Selection and Assessment Volume 14 Issue 3 Page 278 - September 2006. blackwell-synergy.com.","links":[{"url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1468-2389.2006.00346.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"blackwell-synergy.com"}],"url":"https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1468-2389.2006.00346.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":146,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-145","text":"Edelson, M. G. (2006). Are the majority of children with autism mentally retarded? a systematic evaluation of the data. Focus on Autism and Other Developmental Disabilities, 21(2), 66–83. doi: 10.1177/10883576060210020301. SAGE Journals. Accessed October 10 2026.","links":[{"url":"https://journals.sagepub.com/doi/10.1177/10883576060210020301?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"}],"url":"https://journals.sagepub.com/doi/10.1177/10883576060210020301?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":147,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-146","text":"American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (2014). Standards for Educational and Psychological Testing. American Educational Research Association. testingstandards.net. Accessed October 10 2026.","links":[{"url":"https://www.testingstandards.net/uploads/7/6/6/4/76643089/standards_2014edition.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"testingstandards.net"}],"url":"https://www.testingstandards.net/uploads/7/6/6/4/76643089/standards_2014edition.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":148,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-147","text":"Neisser, U., Boodoo, G., Bouchard, T. J., Jr., Boykin, A. W., Brody, N., Ceci, S. J., Halpern, D. F., Loehlin, J. C., Perloff, R., Sternberg, R. J., & Urbina, S. (1995, August 7). Intelligence: Knowns and unknowns. Report of the task force established by the Board of Scientific Affairs, American Psychological Association. Memorial University of Newfoundland — APA report.","links":[{"url":"https://www.mun.ca/biology/scarr/APA%201985%20Intelligence%20-%20Knowns%20and%20Unknowns.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Memorial University of Newfoundland — APA report"}],"url":"https://www.mun.ca/biology/scarr/APA%201985%20Intelligence%20-%20Knowns%20and%20Unknowns.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":149,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-148","text":"Planned Parenthood Sex IQ. (2008). Archived from the original on July 6, 2008. Internet Archive. plannedparenthood.org. Accessed October 10 2026.","links":[{"url":"http://web.archive.org/web/20080706120025/http://www.plannedparenthood.org/health-topics/sex-101/your-sex-iq-4328.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Internet Archive"},{"url":"https://www.plannedparenthood.org/health-topics/sex-101/your-sex-iq-4328.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"plannedparenthood.org"}],"url":"http://web.archive.org/web/20080706120025/http://www.plannedparenthood.org/health-topics/sex-101/your-sex-iq-4328.htm?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":150,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-149","text":"NL Holdem Poker IQ Test. (n.d.). testyourpoker.com. Accessed October 10 2026.","links":[{"url":"https://www.testyourpoker.com/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"testyourpoker.com"}],"url":"https://www.testyourpoker.com/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":151,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#cite_note-150","text":"American Football IQ. (n.d.). footballiqtest.com. Accessed October 10 2026.","links":[{"url":"http://www.footballiqtest.com?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"footballiqtest.com"}],"url":"http://www.footballiqtest.com?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":152,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-152","text":"Carroll, J.B. (1993). Human cognitive abilities: A survey of factor-analytical studies. New York: Cambridge University Press. ISBN 0-521-38275-0. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Cambridge_University_Press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-521-38275-0?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Cambridge_University_Press?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":153,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-153","text":"Lahn, B.T.; Ebenstein, L. (2009). Let's celebrate human genetic diversity. nature (journal) 461 (7265): 726–728. doi:. PMID 19812654. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.nature.com/articles/461726a?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/19812654/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":154,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-154","text":"Coward, W.M.; Sacket, P.R. (1990). Linearity of ability-performance relationships: A reconfirmation. Journal of Applied Psychology 75: 297–300. doi. en.wikipedia.org. psycnet.apa.org:443.","links":[{"url":"https://en.wikipedia.org/wiki/%20Journal_of_Applied_Psychology?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0021-9010.75.3.297&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"}],"url":"https://en.wikipedia.org/wiki/%20Journal_of_Applied_Psychology?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":155,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-155","text":"Duncan, J. et al. (2000). A neural basis for general intelligence. Science 289 (5478): 457–60. doi:. PMID 10903207. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://en.wikipedia.org/wiki/%20Science_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.science.org/doi/10.1126/science.289.5478.457?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"science.org"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/10903207/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Science_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":156,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-156","text":"Cipolotti, L., Ruffle, J. K., Mole, J., Xu, T., Hyare, H., Shallice, T., Chan, E., & Nachev, P. (2023). Graph lesion-deficit mapping of fluid intelligence. Brain, 146(1), 167–181. discovery.ucl.ac.uk. Accessed October 10 2026.","links":[{"url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"discovery.ucl.ac.uk"}],"url":"https://discovery.ucl.ac.uk/id/eprint/10155939/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":157,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-157","text":"Flynn, J.R. (1999). Searching for Justice: The discovery of IQ gains over time. (PDF). American Psychologist 54: 5–20. doi. sites.stat.columbia.edu. en.wikipedia.org. psycnet.apa.org:443. Accessed October 10 2026.","links":[{"url":"https://sites.stat.columbia.edu/gelman/stuff_for_blog/flynn.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"sites.stat.columbia.edu"},{"url":"https://en.wikipedia.org/wiki/%20American_Psychologist?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://psycnet.apa.org:443/doiLanding?doi=10.1037%2F0003-066X.54.1.5&utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"psycnet.apa.org:443"}],"url":"https://sites.stat.columbia.edu/gelman/stuff_for_blog/flynn.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":158,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-158","text":"Frey, M.C.; Detterman, D.K. (2003). Scholastic assessment or g? The relationship between the scholastic assessment test and general cognitive ability. Psychological Science 15 (6): 373–378. doi:. PMID 15147489. en.wikipedia.org. SAGE Journals. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Psychological_Science?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://journals.sagepub.com/doi/10.1111/j.0956-7976.2004.00687.x?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"SAGE Journals"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15147489/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Psychological_Science?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":159,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-159","text":"Gale, C. R., Deary, I. J., Schoon, I., & Batty, G. D. (2007). IQ in childhood and vegetarianism in adulthood: 1970 British cohort study. BMJ, 334(7587), 245. doi: 10.1136/bmj.39030.675069.55. PubMed Central. BMJ. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/","label":"PubMed Central"},{"url":"https://www.bmj.com/content/334/7587/245?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"BMJ"},{"url":"https://pubmed.ncbi.nlm.nih.gov/17175567/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1790759/"},{"number":160,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-160","text":"Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). What Are Intelligence and Creativity? Psychology 2e. OpenStax, Rice University. openstax.org. Accessed October 10 2026.","links":[{"url":"https://openstax.org/books/psychology-2e/pages/7-4-what-are-intelligence-and-creativity?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"openstax.org"}],"url":"https://openstax.org/books/psychology-2e/pages/7-4-what-are-intelligence-and-creativity?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":161,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-161","text":"Gottfredson, L.S. (1998). The general intelligence factor. (PDF). Scientific American Presents 9 (4): 24–29. udel.edu. Accessed October 10 2026.","links":[{"url":"https://www1.udel.edu/educ/gottfredson/reprints/1998generalintelligencefactor.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"udel.edu"}],"url":"https://www1.udel.edu/educ/gottfredson/reprints/1998generalintelligencefactor.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":162,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-162","text":"Gottfredson, L.S. (2005). Suppressing intelligence research: Hurting those we intend to help. In Wright, R.H. and Cummings, N.A (Eds.) (PDF). Destructive trends in mental health: The well-intentioned path to harm. New York: Taylor and Francis. pp. 155–186. ISBN 0-415-95086-4. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","links":[{"url":"https://www1.udel.edu/educ/gottfredson/reprints/2005suppressingintelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"www1.udel.edu"},{"url":"https://en.wikipedia.org/wiki/%20Taylor_and_Francis?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-415-95086-4?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://www1.udel.edu/educ/gottfredson/reprints/2005suppressingintelligence.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":163,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-163","text":"Gottfredson, L.S. (2006). Social consequences of group differences in cognitive ability (Consequencias sociais das diferencas de grupo em habilidade cognitiva). In Flores-Mendoza, C.E. and Colom, R. (Eds.) (PDF). Introdução à psicologia das diferenças individuais. Porto Alegre, Brazil: ArtMed Publishers. pp. 155–186. ISBN 8-536-30621-1. www1.udel.edu. en.wikipedia.org. en.wikipedia.org. Accessed October 10 2026.","links":[{"url":"https://www1.udel.edu/educ/gottfredson/reprints/2004socialconsequences.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"www1.udel.edu"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/8-536-30621-1?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://www1.udel.edu/educ/gottfredson/reprints/2004socialconsequences.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":164,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-164","text":"Gould, S.J. (1996). W. W. Norton & Co. ed. The Mismeasure of Man: Revised and Expanded Edition. New-York: Penguin. ISBN 0140258248. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Stephen_Jay_Gould?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0140258248?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Stephen_Jay_Gould?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":165,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-165","text":"Gray, J.R.; Chabris, C.F.; Brave,r T.S. (2003). Neural mechanisms of general fluid intelligence. Nat. Neurosci. 6 (3): 316–22. doi:. PMID 12592404. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nat._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.nature.com/articles/nn1014?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/12592404/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Nat._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":166,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-166","text":"Gray JR, Thompson PM. (2004). Neurobiology of intelligence: science and ethics. Nat. Rev. Neurosci. 5 (6): 471–82. doi:. PMID 15152197. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nat._Rev._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.nature.com/articles/nrn1405?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15152197/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Nat._Rev._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":167,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-167","text":"Rosalind Franklin University. (2021). Massive study led by Rosalind Franklin University neuroscientists reveals few differences between men and women’s brains. Rosalind Franklin University. rosalindfranklin.edu. Accessed October 10 2026.","links":[{"url":"https://www.rosalindfranklin.edu/news/massive-study-led-by-rosalind-franklin-university-neuroscientists-reveals-few-differences-between-men-and-women-s-brains/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"rosalindfranklin.edu"}],"url":"https://www.rosalindfranklin.edu/news/massive-study-led-by-rosalind-franklin-university-neuroscientists-reveals-few-differences-between-men-and-women-s-brains/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":168,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-168","text":"Harris, J.R. (1998). The nurture assumption : why children turn out the way they do. New York (NY): Free Press. ISBN 0-684-84409-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Free_Press_(publisher)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-684-84409-5?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Free_Press_(publisher)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":169,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-169","text":"Hunt, E. (2001). Multiple views of multiple intelligence. [Review of Intelligence Reframed: Multiple Intelligences for the 21st Century.]. Contemporary Psychology 46: 5–7.","links":[]},{"number":170,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-170","text":"Jensen, A.R. (1979). Bias in mental testing. New York (NY): Free Press. ISBN 0-029-16430-3. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Free_Press_(publisher)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-029-16430-3?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Free_Press_(publisher)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":171,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-171","text":"Jensen, A.R. (1979). The g Factor: The Science of Mental Ability. Wesport (CT): Praeger Publishers. ISBN 0-275-96103-6. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Praeger_Publishers?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-275-96103-6?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Praeger_Publishers?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":172,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-172","text":"Jensen, A.R. (2006). Clocking the Mind: Mental Chronometry and Individual Differences. Elsevier. ISBN 0-080-44939-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Elsevier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-080-44939-5?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Elsevier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":173,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-173","text":"Kaufman, A.S. (2009). IQ Testing 101. New York (NY): Springer Publishing. ISBN 978-0-8261-0629-2. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Springer_Publishing?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/978-0-8261-0629-2?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Springer_Publishing?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":174,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-174","text":"Klingberg, T.; Forssberg, H.; Westerberg, H. (2002). Training of working memory in children with Attention-deficit/hyperactivity disorder (ADHD). J Clin Exp Neuropsychol 24 (6): 781–91. doi:. PMID 12424652. Taylor & Francis. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://www.tandfonline.com/doi/full/10.1076/jcen.24.6.781.8395?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Taylor & Francis"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/12424652/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.tandfonline.com/doi/full/10.1076/jcen.24.6.781.8395?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":175,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-175","text":"McClearn, G.E. et al. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science 276 (5318): 1560–1563. doi:. PMID 9171059. en.wikipedia.org. science.org. en.wikipedia.org. National Library of Medicine.","links":[{"url":"https://en.wikipedia.org/wiki/%20Science_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.science.org/doi/10.1126/science.276.5318.1560?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"science.org"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/9171059/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Science_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":176,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-176","text":"Bratsberg, B., & Rogeberg, O. (2018). Flynn effect and its reversal are both environmentally caused. Proceedings of the National Academy of Sciences, 115(26), 6674–6678. PubMed Central. Accessed October 8 2026.","links":[{"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC6042097/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"PubMed Central"}],"url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC6042097/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":177,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-177","text":"Murray, C. (1998). (PDF). Income Inequality and IQ. Washington (DC): AEI Press. ISBN 0-8447-7094-9. aei.org. en.wikipedia.org. en.wikipedia.org. aei.org. Accessed October 10 2026.","links":[{"url":"https://www.aei.org/events/income-inequality-and-iq/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"aei.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-8447-7094-9?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.aei.org/wp-content/uploads/2011/10/20040302_book443.pdf?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"aei.org"}],"url":"https://www.aei.org/events/income-inequality-and-iq/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":178,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-178","text":"Noguera, P.A. (2001). Racial politics and the elusive quest for excellence and equity in education. Motion Magazine. Article # ER010930002. inmotionmagazine.com. Accessed October 10 2026.","links":[{"url":"http://www.inmotionmagazine.com/er/pnrp1.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"inmotionmagazine.com"}],"url":"http://www.inmotionmagazine.com/er/pnrp1.html?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":179,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-179","text":"Plomin, R.; DeFries, J.C.; Craig, I.W.; McGuffin, P. (2003). Behavioral genetics in the postgenomic era. Washington (DC): American Psychological Association. ISBN 1-557-98926-5. en.wikipedia.org. en.wikipedia.org. en.wikipedia.org. Accessed August 6 2006.","links":[{"url":"https://en.wikipedia.org/wiki/%20American_Psychological_Association?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/1-557-98926-5?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20American_Psychological_Association?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":180,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-180","text":"Plomin, R.; DeFries, J.C.; McClearn, G.E.; McGuffin, P. (2000). Behavioral genetics. (4th ed.). New York (NY): Worth Publishers Scientific American Presents. ISBN 0-716-75159-3. en.wikipedia.org. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://en.wikipedia.org/wiki/%20Special:BookSources/0-716-75159-3?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20International_Standard_Book_Number?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":181,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-181","text":"Rowe, D.C.; Vesterdal, W.J.; Rodgers, J.L. (1997). The Bell Curve Revisited: How Genes and Shared Environment Mediate IQ-SES Associations. [verification needed]. en.wikipedia.org.","links":[{"url":"https://en.wikipedia.org/wiki/%20Wikipedia:Verifiability?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"}],"url":"https://en.wikipedia.org/wiki/%20Wikipedia:Verifiability?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":182,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-182","text":"Schoenemann PT, Sheehan MJ, Glotzer LD. (2005, February). Prefrontal white matter volume is disproportionately larger in humans than in other primates. Nature Neuroscience 8 (2): 242–52. doi:. PMID 15665874. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://www.nature.com/articles/nn1394?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/15665874/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://www.nature.com/articles/nn1394?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":183,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-183","text":"Shaw, P. et al. (2006). Intellectual ability and cortical development in children and adolescents. Nature 440 (7084): 676–679. doi:. PMID 16572172. en.wikipedia.org. Nature. en.wikipedia.org. National Library of Medicine. Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.nature.com/articles/nature04513?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/16572172/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Nature_(journal)?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":184,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-184","text":"Tambs, K.; Sundet, J.M.; Magnus, P.; Berg, K. 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Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Behav._Genet.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://link.springer.com/article/10.1007/BF01065905?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Springer"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/2719624/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Behav._Genet.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":185,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-185","text":"Thompson, P.M. et al. 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Accessed October 10 2026.","links":[{"url":"https://en.wikipedia.org/wiki/%20Nat._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://www.nature.com/articles/nn758?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"Nature"},{"url":"https://en.wikipedia.org/wiki/%20PubMed_Identifier?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"en.wikipedia.org"},{"url":"https://pubmed.ncbi.nlm.nih.gov/11694885/?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com","label":"National Library of Medicine"}],"url":"https://en.wikipedia.org/wiki/%20Nat._Neurosci.?utm_medium=referral&utm_campaign=libra&utm_content=external_resource&utm_id=site-library-psychological-testing-intelligence-quotient&utm_source=mentalhealth.com"},{"number":186,"id":"https://www.mentalhealth.com/library/psychological-testing-intelligence-quotient#source-393-186","text":"Wechsler, D. 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