Dunning–Kruger effect
The Dunning–Kruger effect is a cognitive bias that describes the systematic tendency of people with low ability in a specific area to give overly positive assessments of this ability. The term may also describe the tendency of high performers to underestimate their skills. It was first described by the psychologists David Dunning and Justin Kruger in 1999. In popular culture, the Dunning–Kruger effect is sometimes misunderstood as claiming that people with low intelligence are generally overconfident, instead of describing the specific overconfidence of people unskilled at particular areas.
The Dunning–Kruger effect has been demonstrated across multiple studies in a wide range of tasks from fields such as business, politics, medicine, driving, aviation, spatial memory, examinations in school, and literacy. The original study by Dunning and Kruger focused on logical reasoning, grammar, and social skills. The effect is usually measured by comparing self-assessment with objective performance. For example, participants may take a quiz and estimate their performance afterward, and their estimates are then compared to their actual results.
A number of explanations for, and criticisms of, the Dunning–Kruger effect have been proposed. The metacognitive explanation holds that poor performers misjudge their abilities because they lack the ability to recognize the qualitative difference between their performances and the performances of others. The statistical explanation holds that the empirical effect may largely be the result of a mere statistical effect and the fact that people have a general tendency to think that one is better than average. The rational explanation 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 the practical consequences of the effect. Inaccurate self-assessment could potentially lead people to making bad decisions, such as choosing a career for which they are unfit, engaging in dangerous behavior, and inhibiting people from addressing their shortcomings to improve themselves.
Definition
The Dunning–Kruger effect is the tendency of people with low ability in a specific area to give overly positive assessments of this ability. This is often seen as a cognitive bias, that is, a systematic tendency to engage in erroneous forms of thinking and judging. In the case of the Dunning–Kruger effect, the systematic error concerns people with low skill in a specific area trying to evaluate their competence within this area and their tendency to greatly overestimate their competence.The Dunning–Kruger effect is usually defined specifically for the self-assessments of people with a low level of competence. But some theorists do not only restrict it to the bias of people with low skill but also use it to describe the reverse effect, the tendency of highly skilled people to underestimate their abilities relative to the abilities of others. In this case, the source of the error may not be the self-assessment of one's skills, but an overly positive assessment of the skills of others. This phenomenon can be understood as a form of the false-consensus effect, the tendency to "overestimate the extent to which other people share one's beliefs, attitudes, and behaviours".
Some researchers include a metacognitive component in their definition. In this view, the Dunning–Kruger effect is the thesis that those who are incompetent in a given area tend to be ignorant of their incompetence; they lack the metacognitive ability to become aware of their incompetence. As incompetence often includes being unable to tell the difference between competence and incompetence, it is difficult for the incompetent to recognize their incompetence. This is sometimes termed the "dual-burden" account, since low performers are affected by two burdens: they lack a skill and they are unaware of this deficiency. Other definitions focus on the tendency to overestimate one's ability and see the relation to metacognition as a possible explanation that is not part of the definition. This contrast is relevant since the metacognitive explanation is controversial. Many criticisms of the Dunning–Kruger effect target this explanation but accept the empirical findings that low performers tend to overestimate their skills.
Among laypeople, the Dunning–Kruger effect is often misunderstood as the claim that people with low intelligence are more confident in their knowledge and skills than people with high intelligence. According to psychologist Robert D. McIntosh and his colleagues, it is sometimes understood in popular culture as the claim that "stupid people are too stupid to know they are stupid". But the Dunning–Kruger effect applies not to intelligence in general but to skills in specific tasks. Nor does it claim that people lacking a given skill are as confident as high performers. Rather, low performers overestimate themselves but their confidence level is still below that of high performers.
Measurement, analysis, and investigated tasks
The most common approach to measuring the Dunning–Kruger effect is to compare self-assessment with objective performance. The self-assessment is sometimes called subjective ability in contrast to the objective ability corresponding to the actual performance. The self-assessment may be done before or after the performance. If done afterward, the participants receive no independent clues during the performance as to how well they did. Thus, if the activity involves answering quiz questions, no feedback is given as to whether a given answer was correct.The measurement of the subjective and the objective abilities can be in absolute or relative terms. When done in absolute terms, self-assessment and performance are measured according to objective standards, e.g. concerning how many quiz questions were answered correctly. When done in relative terms, the results are compared with a peer group. In this case, participants are asked to assess their performances in relation to the other participants, for example in the form of estimating the percentage of peers they outperformed. The Dunning–Kruger effect is present in both cases, but tends to be significantly more pronounced when done in relative terms; people are usually less accurate when assessing how well they did relative to their peer group than when simply predicting their raw score.
The main point of interest for researchers is usually the correlation between subjective and objective ability. To provide a simplified form of analysis of the measurements, objective performances are often divided into four groups. They start from the bottom quartile of low performers and proceed to the top quartile of high performers. The strongest effect is seen for the participants in the bottom quartile, who tend to see themselves as being part of the top two quartiles when measured in relative terms.
The initial study by David Dunning and Justin Kruger examined the performance and self-assessment of undergraduate students in inductive, deductive, and abductive logical reasoning; English grammar; and appreciation of humor. Across four studies, the research indicates that the participants who scored in the bottom quartile overestimated their test performance and their abilities. Their test scores placed them in the 12th percentile, but they ranked themselves in the 62nd percentile. Other studies focus on how a person's self-view causes inaccurate self-assessments. Some studies indicate that the extent of the inaccuracy depends on the type of task and can be improved by becoming a better performer.
Overall, the Dunning–Kruger effect has been studied across a wide range of tasks, in aviation, business, debating, chess, driving, literacy, medicine, politics, spatial memory, and other fields. Many studies focus on students—for example, how they assess their performance after an exam. In some cases, these studies gather and compare data from different countries. Studies are often done in laboratories; the effect has also been examined in other settings, including assessments of hunters' knowledge of firearms and large Internet surveys.
Explanations
Various theorists have tried to provide models to explain the Dunning–Kruger effect's underlying causes. The original explanation by Dunning and Kruger holds that a lack of metacognitive abilities is responsible. This interpretation is not universally accepted, and many alternative explanations have been proposed. Some of them focus only on one specific factor, while others see a combination of various factors as the cause.Metacognitive
The metacognitive explanation rests on the idea that part of acquiring a skill consists in learning to distinguish between good and bad performances of the skill. It assumes that people of low skill level are unable to properly assess their performance because they have not yet acquired the discriminatory ability to do so. This leads them to believe that they are better than they actually are because they do not see the qualitative difference between their performance and that of others. In this regard, they lack the metacognitive ability to recognize their incompetence. This model has also been called the "dual-burden account" or the "double-burden of incompetence", since the burden of regular incompetence is paired with the burden of metacognitive incompetence. The metacognitive lack may hinder some people from becoming better by hiding their flaws from them. This can then be used to explain how self-confidence is sometimes higher for unskilled people than for people with an average skill: only the latter are aware of their flaws.Some attempts have been made to measure metacognitive abilities directly to examine this hypothesis. Some findings suggest that poor performers have reduced metacognitive sensitivity, but it is not clear that its extent is sufficient to explain the Dunning–Kruger effect. Another study concluded that unskilled people lack information but that their metacognitive processes have the same quality as those of skilled people. An indirect argument for the metacognitive model is based on the observation that training people in logical reasoning helps them make more accurate self-assessments. Many criticisms of the metacognitive model hold that it has insufficient empirical evidence and that alternative models offer a better explanation.