The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than is accurate. This bias is attributed to a metacognitive inability of the unskilled to recognize their ineptitude. Actual competence may weaken self-confidence, as competent individuals may falsely assume that others have an equivalent understanding.
David Dunning and Justin Kruger of Cornell University conclude, “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”.
The phenomenon was first tested in a series of experiments published in 1999 by David Dunning and Justin Kruger of the Department of Psychology, Cornell University.They noted earlier studies suggesting that ignorance of standards of performance is behind a great deal of incompetence. This pattern was seen in studies of skills as diverse as reading comprehension, operating a motor vehicle, and playing chess or tennis.
Dunning and Kruger proposed that, for a given skill, incompetent people will:
- tend to overestimate their own level of skill;
- fail to recognize genuine skill in others;
- fail to recognize the extremity of their inadequacy;
- recognize and acknowledge their own previous lack of skill, if they are exposed to training for that skill.
Dunning has since drawn an analogy (“the anosognosia of everyday life”) with a condition in which a person who suffers a physical disability because of brain injury seems unaware of or denies the existence of the disability, even for dramatic impairments such as blindness or paralysis.