In the field of psychology, the Dunning–Kruger effect is a cognitive bias wherein persons of low ability suffer from illusory
superiority, mistakenly assessing their cognitive ability as greater than it is. The cognitive bias of illusory
superiority derives from the metacognitive inability of low-ability persons to recognize their own ineptitude. Without the self-awareness of metacognition, low-ability people cannot objectively evaluate their actual competence or
incompetence.
As described by David Dunning and Justin Kruger, the cognitive bias of illusory superiority results from an internal illusion in people of low ability and from an external misperception in people of high ability; that is, "the miscalibration of the
incompetent stems from an error about the self, whereas the miscalibration of the highly competent stems from an error about others." Hence, the corollary to the Dunning–Kruger effect indicates that persons of high ability tend to underestimate their relative competence, and erroneously presume that tasks that are easy for them to perform also are easy for other people to perform.
