cover image

Dunning–Kruger effect

Cognitive bias about one's own skill / From Wikipedia, the free encyclopedia

Dear Wikiwand AI, let's keep it short by simply answering these key questions:

Can you list the top facts and stats about Dunning–Kruger effect?

Summarize this article for a 10 years old


The Dunning–Kruger effect is a cognitive bias[2] whereby people with low ability, expertise, or experience regarding a type of task or area of knowledge tend to overestimate their ability or knowledge. 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.

Graph showing the difference between self-perceived and actual performance
Relation between average self-perceived performance and average actual performance on a college exam.[1] The red area shows the tendency of low performers to overestimate their abilities. Nevertheless, low performers' self-assessment is lower than that of high performers.

The Dunning–Kruger effect is usually measured by comparing self-assessment with a measure of objective performance. For example, the participants in a study may be asked to complete a quiz and then estimate how well they performed. This subjective assessment is then compared with how well they actually performed. This can happen in either relative or absolute terms, i.e., in comparison with one's peer group as the percentage of peers outperformed or in comparison with objective standards as the number of questions answered correctly. The Dunning–Kruger effect appears in both cases, but is more pronounced in relative terms. The initial study was published by David Dunning and Justin Kruger in 1999. It focused on logical reasoning, grammar, and social skills. Since then 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.

Many models have been suggested to explain the Dunning-Kruger effect's underlying causes. According to the metacognitive explanation, poor performers have not yet acquired the ability to distinguish between good and bad performances. They tend to overrate themselves because they do not see the qualitative difference between their performances and the performances of others. The statistical model explains the empirical findings based on two effects. It combines the statistical effect known as regression toward the mean with the cognitive bias known as the better-than-average effect. 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 are disagreements about the magnitude and practical consequences of the Dunning–Kruger effect. Inaccurate self-assessment can lead people to make bad decisions, such as choosing a career for which they are unfit or engaging in dangerous behavior. It may also inhibit the affected from addressing their shortcomings to improve themselves. In some cases, the associated overconfidence may have positive side effects, like increasing motivation and energy.