The Dunning–Kruger effect is a cognitive bias wherein relatively unskilled individuals suffer from illusory superiority, mistakenly assessing their ability to be much higher than is accurate. Dunning and Kruger attributed this bias to a metacognitive inability of the unskilled to recognize their own ineptitude and evaluate their own ability accurately. Their research also suggests corollaries: highly skilled individuals may underestimate their relative competence, they may erroneously assume that tasks which are easy for them are also easy for others, and they may incorrectly suppose that their competence in a particular field extends to other fields in which they are less competent. The bias was first experimentally observed by David Dunning and Justin Kruger of Cornell University in 1999.
Dunning and Kruger have postulated that the effect is the result of internal illusion in the unskilled, and external misperception in the skilled: “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.
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