What is impostor syndrome in simple terms?

It is the nagging feeling that you are not as competent as others think and that you will eventually be found out, even when your record shows you are doing well. Many accomplished people experience it.

Is impostor syndrome a mental illness?

No. It is not listed as a disorder in the DSM-5 or ICD-11. Researchers describe it as a pattern of thinking, which is why the original term was the impostor phenomenon. It can occur alongside anxiety or depression, which are diagnosable.

Who first described impostor syndrome?

Psychologists Pauline Rose Clance and Suzanne Imes described the impostor phenomenon in a 1978 paper, based on high-achieving women who believed they were not truly intelligent despite strong academic and professional records.

Is impostor syndrome the opposite of the Dunning–Kruger effect?

In a loose sense. The Dunning–Kruger effect describes people with low skill overrating themselves; impostor syndrome describes skilled people underrating themselves. They are separate findings, though, not two ends of one measured scale.

Impostor syndrome

Also known as the impostor phenomenon · Self-assessment

Impostor syndrome is a pattern of persistent self-doubt in which capable people feel their success is undeserved and fear being exposed as a fraud. Also called the impostor phenomenon, it is a common experience rather than a clinical diagnosis.

By the ReadGlobe Editors · Reviewed 2026-10-24

1 min read
7 linked ideas

Why does impostor syndrome happen?

People see their own effort, uncertainty and near-misses in full, but see only the polished results of others. Success then gets credited to luck, timing or charm, while any slip is taken as proof of inadequacy. New roles, visible achievements and being one of few people like yourself in a setting can all intensify the feeling. Perfectionism keeps it going: over-preparing leads to success, which is put down to the over-preparation rather than ability, so the doubt survives every piece of evidence against it.

What does impostor syndrome look like in real life?

A newly promoted manager convinced the selection panel made a mistake and will soon notice.
A doctoral student who assumes every classmate understands the material better than they do.
Dismissing praise for a successful project as people “just being nice.”
Pauline Clance and Suzanne Imes first described the pattern in 1978 among high-achieving women they saw in therapy.

How do you counter impostor syndrome?

Keep a written record of concrete achievements and the feedback behind them, and reread it when doubt flares.
Talk to peers; hearing that others feel the same weakens the sense of being uniquely unqualified.
If the self-doubt is constant or affecting your health, speak to a doctor or a qualified therapist.

Frequently asked

What is impostor syndrome in simple terms?: It is the nagging feeling that you are not as competent as others think and that you will eventually be found out, even when your record shows you are doing well. Many accomplished people experience it.
Is impostor syndrome a mental illness?: No. It is not listed as a disorder in the DSM-5 or ICD-11. Researchers describe it as a pattern of thinking, which is why the original term was the impostor phenomenon. It can occur alongside anxiety or depression, which are diagnosable.
Who first described impostor syndrome?: Psychologists Pauline Rose Clance and Suzanne Imes described the impostor phenomenon in a 1978 paper, based on high-achieving women who believed they were not truly intelligent despite strong academic and professional records.
Is impostor syndrome the opposite of the Dunning–Kruger effect?: In a loose sense. The Dunning–Kruger effect describes people with low skill overrating themselves; impostor syndrome describes skilled people underrating themselves. They are separate findings, though, not two ends of one measured scale.

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APA

ReadGlobe. (2026). Impostor syndrome. https://readglobe.com/bias/impostor-syndrome/

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"Impostor syndrome." ReadGlobe, 24 Oct. 2026, readglobe.com/bias/impostor-syndrome/.

Editorial synthesis © ReadGlobe 2026, drawing on Kahneman’s Thinking, Fast and Slow, the Tversky–Kahneman research program, and the primary cognitive-science literature. · Last reviewed 2026-10-24.