The 5 impostor types
Expert Valerie Young identified five ways of understanding competence that fuel impostor syndrome: the perfectionist (if it's not perfect, it doesn't count), the expert (if I don't know everything, I know nothing), the natural genius (if it's hard, I'm not good enough), the soloist (if I ask for help, it doesn't count) and the superhero (I have to handle everything).
Young stresses that these aren't personality labels but ways of measuring yourself. Identifying yours helps you question it.
A very common phenomenon
Psychologists Pauline Clance and Suzanne Imes described it in 1978. It isn't a clinical diagnosis and it affects a huge number of brilliant people, especially in demanding environments or when taking a career leap.