Dunning–Kruger effect

Cognitive bias about one's own skill

The Dunning–Kruger effect is a cognitive bias in which people with limited competence in a particular domain overestimate their abilities. It was first described by Justin Kruger and David Dunning in 1999. Some researchers also include the opposite effect for high performers: their tendency to underestimate their skills. In popular culture, the Dunning–Kruger effect is often misunderstood as a claim about general overconfidence of people with low intelligence instead of specific overconfidence of people unskilled at a particular task.

Numerous similar studies have been done. The Dunning–Kruger effect is usually measured by comparing self-assessment with objective performance. For example, participants may take a quiz and estimate their performance afterward, which is then compared to their actual results. The original study focused on logical reasoning, grammar, and social skills. Other studies have been conducted across a wide range of tasks. They include skills from fields such as business, politics, medicine, driving, aviation, spatial memory, examinations in school, and literacy.

There is disagreement about the causes of the Dunning–Kruger effect. According to the metacognitive explanation, poor performers misjudge their abilities because they fail to recognize the qualitative difference between their performances and the performances of others. The statistical model explains the empirical findings as a statistical effect in combination with the general tendency to think that one is better than average. Some proponents of this view hold that the Dunning–Kruger effect is mostly a statistical artifact. The rational model holds that overly positive prior beliefs about one's skills are the source of false self-assessment. Another explanation claims that self-assessment is more difficult and error-prone for low performers because many of them have very similar skill levels.

There is also disagreement about where the effect applies and about how strong it is, as well as about its practical consequences. Inaccurate self-assessment could potentially lead people to making bad decisions, such as choosing a career for which they are unfit, or engaging in dangerous behavior. It may also inhibit people from addressing their shortcomings to improve themselves. Critics argue that such an effect would have much more dire consequences than what is observed.

1. ^ Dunning 2011, p. 263.

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