Such women tortuously assume any personal success must have been achieved with anything other than basic capability or flair; they fear it's only a matter of time before others discover that they truly lack ability.
New research by psychologists Shamala Kumar and Carolyn M Jagacinski at Purdue University in the US confirms that sufferers from impostor syndrome are more usually women than men. This explains why so many successful women don't put themselves forward for promotion or are less assertive in their careers than less able men.
In their investigation of the syndrome, soon to be published in the academic journal Personality and Individual Differences, Kumar and Jagacinski found that women were much less confident about their basic intelligence and consequently were more anxious about feedback on their performance. They tended to avoid any chance of public failure and, as a result, did not take on tasks that could result in promotion. This could explain the stereotype of women being better "team players" than men: hiding individual performance in a team means you are less exposed to direct personal negative evaluation if things don't go well.
According to this new research, sufferers from impostor syndrome over-generalise the implications of single failures. For example, if they fail one exam, they believe they are intellectually useless generally and will fail all future exams.
Kumar and Jagacinski's study suggests a strategy for women (and the few men who live with the same syndrome) which could liberate them. They say that it's worth taking on difficult tasks, whether you succeed or not, because you benefit from the challenge. You learn things and improve your basic skills. The danger for impostor syndrome sufferers is that they don't realise they will not be cured by success - even if they rise to the top.
Instead they could feel worse, as each success merely deepens their stress as they fear even more of a collapse when they are finally revealed to be the hoaxer they believe they are. True confidence in life isn't about how you feel after a success. It's about how you respond to failure; how you cannot let it convince you that all your previous successes must have been a fraud.
Dr Raj Persaud is Gresham professor for public understanding of psychiatry, and director of the Centre for Public Engagement, King's College London.
His latest book is The Motivated Mind (Bantam Press). Email: firstname.lastname@example.org