What is a complex?

Medically reviewed by Jesse Hanson, Ph.D.Jesse Hanson, Ph.D. Written by Mark Dombeck, Ph.D.Mark Dombeck, Ph.D. – Updated on September 7, 2025

Question

Hi Dr. could you please explain to me what a complex is and what causes them. could you also explain to me what a person fears the most such as a fear of abandonment they cause to happen with there behavior like a self fulfilling prophesy. thank you.

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Answer

A complex is an informal term for what happens when someone develops a belief (often an exadurated belief) that a particular situation is dangerous or embarrassing. For example, you might say, “For heaven’s sake, don’t call attention to her nose being so big! You’ll give her a complex”.

The complex that our large-nosed protagonist might develop would be a belief that there was something wrong with the size of her nose. The person with the ‘complex’ might become so alarmed about her nose problem that she’d seek out the services of a plastic surgeon to correct things. The danger here being that in reality, there really wasn’t anything wrong with the nose in question, save for a few cruel comments and some insecurity (these two ingredients being the cause of most ‘complexes’).

A self-fulfilling prophesy occurs when someone is afraid of something happening and then allows that fear to drive their responses in such a way as to cause that very feared thing to happen. As an illustration, consider someone who is socially phobic with regard to asking for dates.

The fear here is one of rejection. The fearful suitor imagines the feared rejection in detail, and it becomes so vivid and ‘real’ that the suitor starts reacting to the object of their affection as though the feared rejection is a done deal; as though the rejection has already occurred.

While being asked out, the object of the suitor’s affections is subjected to powerful mixed messages that convey the suitor’s belief that he or she is rejectable. The actual request for a date comes out all wrong, “Would you like to go out with me sometime, I mean, maybe, well, if you’re not busy which you probably are, oh well, forget about it.”. The person being asked out has to really already want to date the person who asks them out in this manner, because the method of asking is so clumsy as to turn off someone who is merely ambivalent.

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Jesse Hanson, Ph.D.
Medical Reviewer
Clinical Affairs Director

Jesse Hanson, Ph.D., is a somatic psychologist with more than 20 years of experience in clinical psychology and neuropsychology.

Published
May 31, 2024
Updated
Sep 07, 2025

Mark Dombeck, Ph.D.
Author
Medical Reviewer, Writer

Mark Dombeck, Ph.D. is a trauma-informed psychologist with over 30 years of experience helping people navigate mental health challenges.

Published
May 31, 2024
Updated
Sep 07, 2025
Medical Content

The Clinical Affairs Team at MentalHealth.com is a dedicated group of medical professionals with diverse and extensive clinical experience. They actively contribute to the development of content, products, and services, and meticulously review all medical material before publication to ensure accuracy and alignment with current research and conversations in mental health. For more information, please visit the Editorial Policy.

About MentalHealth.com

We are a health technology company that guides people toward self-understanding and connection. The platform provides reliable resources, accessible services, and nurturing communities. Its purpose is to educate, support, and empower people in their pursuit of well-being.