Psychological Testing: Stanford-Binet IQ Test

The development of the Stanford-Binet Intelligence Scales initiated the modern field of intelligence testing, originating in France, then revised in the U.S. The Stanford-Binet test started with the French psychologist Alfred Binet (1857-1911), whom the French government commissioned with developing a method of identifying intellectually deficient children for their placement in special-education programs. As Binet indicated, case studies might be more detailed and helpful, but the time required to test many people would be excessive. In 1916, at Stanford University, the psychologist Lewis Terman released a revised examination which became known as the “Stanford-Binet test”.

Development

Later, Alfred Binet and physician Theodore Simon collaborated in studying mental retardation in French school children. Theodore Simon was a student of Binet’s. ^[1] Between 1905 and 1908, their research at a boys school, in Grange-aux-Belles, led to their developing the Binet-Simon tests; assessing attention, memory, and verbal skill. The test consisted of 30 items ranging from the ability to touch one’s nose or ear, when asked, to the ability to draw designs from memory and to define abstract concepts,^[1] and varying in difficulty. Binet proposed that a child’s intellectual ability increases with age, and after determining the age at which a typical child could answer them correctly, he developed the concept of mental age (MA): an individual’s level of mental development relative to others^[1]. Binet placed a confidence interval around the scores returned from his tests, both because he thought intelligence was somewhat plastic, and because of inherent margin of error in psychometric tests (Fancher, 1985).

In 1916, the Stanford psychologist Lewis Terman released the “Stanford Revision of the Binet-Simon Scale”, the “Stanford-Binet”, for short. Helped by graduate students and validation experiments, he removed some Binet-Simon test items and added new ones. Soon, the test was so popular that Robert Yerkes, the president of the American Psychological Association, decided to use it in developing the Army Alpha and the Army Beta tests to classify recruits. Thus, a high-scoring recruit might earn an A-grade (high officer material), whereas a low-scoring recruit with an E-grade would be rejected for military service. (Fancher, 1985).

Present use

Since the inception of the Stanford-Binet, it has been revised several times. Currently, the test is in its fifth edition, which is called the Stanford-Binet 5. According to the publisher’s website, “The SB5 was normed on a stratified random sample of 4,800 individuals that matches the 2000 U. S. Census.” By administering the Stanford-Binet test to large numbers of individuals selected at random from different parts of the United States, it has been found that the scores approximate a normal distribution.

See also

• The Flynn effect

Further reading