The Lake Wobegon effect

lake-wobegonIllusory superiority is a cognitive bias that causes people to overestimate their positive qualities and abilities and to underestimate their negative qualities, relative to others. This is evident in a variety of areas including intelligence, performance on tasks or tests, and the possession of desirable characteristics or personality traits. It is one of many positive illusions relating to the self, and is a phenomenon studied in social psychology.

Illusory superiority is often referred to as the above average effect. Other terms include superiority bias, leniency error, sense of relative superiority, the primus inter pares effect, and the Lake Wobegon effect (named after Garrison Keillor’s fictional town where “all the children are above average”). The phrase “illusory superiority” was first used by Van Yperen and Buunk in 1991.


Illusory superiority has been found in individuals’ comparisons of themselves with others in a wide variety of different aspects of life, including performance in academic circumstances (such as class performance, exams and overall intelligence), in working environments (for example in job performance), and in social settings (for example in estimating one’s popularity, or the extent to which one possesses desirable personality traits, such as honesty or confidence), as well as everyday abilities requiring particular skill.

For illusory superiority to be demonstrated by social comparison, two logical hurdles have to be overcome. One is the ambiguity of the word “average”. It is logically possible for nearly all of the set to be above the mean if the distribution of abilities is highly skewed. For example, the mean number of legs per human being is slightly lower than two, because of a small number of people have only one or no legs. Hence experiments usually compare subjects to the median of the peer group, since by definition it is impossible for a majority to exceed the median.

A further problem in inferring inconsistency is that subjects might interpret the question in different ways, so it is logically possible that a majority of them are, for example, more generous than the rest of the group each on their own understanding of generosity. This interpretation is confirmed by experiments which varied the amount of interpretive freedom subjects were given. As subjects evaluate themselves on a specific, well-defined attribute, illusory superiority remains.

Cognitive ability – IQ

3pft4nOne of the main effects of illusory superiority in IQ is the Downing effect. This describes the tendency of people with a below average IQ to overestimate their IQ, and of people with an above average IQ to underestimate their IQ. The propensity to predictably misjudge one’s own IQ was first noted by C. L. Downing who conducted the first cross-cultural studies on perceived ‘intelligence’. His studies also evidenced that the ability to accurately estimate others’ IQ was proportional to one’s own IQ. This means that the lower the IQ of an individual, the less capable they are of appreciating and accurately appraising others’ IQ. Therefore individuals with a lower IQ are more likely to rate themselves as having a higher IQ than those around them. Conversely, people with a higher IQ, while better at appraising others’ IQ overall, are still likely to rate people of similar IQ as themselves as having higher IQs.

The disparity between actual IQ and perceived IQ has also been noted between genders by British psychologist Adrian Furnham, in whose work there was a suggestion that, on average, men are more likely to overestimate their intelligence by 5 points, while women are more likely to underestimate their IQ by a similar margin.


Illusory superiority has been found in studies comparing memory self-report, such as Schmidt, Berg & Deelman’s research in older adults. This study involved participants aged between 46 and 89 years of age comparing their own memory to that of peers of the same age group, 25-year-olds and their own memory at age 25. This research showed that participants exhibited illusory superiority when comparing themselves to both peers and younger adults, however the researchers asserted that these judgements were only slightly related to age.

Cognitive tasks

Bertrand Russell Dunning Kruger effectIn Kruger and Dunning’s experiments participants were given specific tasks (such as solving logic problems, analyzing grammar questions, and determining whether or not jokes were funny), and were asked to evaluate their performance on these tasks relative to the rest of the group, enabling a direct comparison of their actual and perceived performance.

Results were divided into four groups depending on actual performance and it was found that all four groups evaluated their performance as above average, meaning that the lowest-scoring group (the bottom 25%) showed a very large illusory superiority bias. The researchers attributed this to the fact that the individuals who were worst at performing the tasks were also worst at recognizing skill in those tasks. This was supported by the fact that, given training, the worst subjects improved their estimate of their rank as well as getting better at the tasks.

The paper, titled “Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments,” won a 2000 Ig Nobel Prize.

In 2003 Dunning and Joyce Ehrlinger, also of Cornell University, published a study that detailed a shift in people’s views of themselves influenced by external cues. Participants in the study (Cornell University undergraduates) were given tests of their knowledge of geography, some intended to positively affect their self-views, some intended to affect them negatively. They were then asked to rate their performance, and those given the positive tests reported significantly better performance than those given the negative.

Daniel Ames and Lara Kammrath extended this work to sensitivity to others, and the subjects’ perception of how sensitive they were. Work by Burson Larrick and Joshua Klayman has suggested that the effect is not so obvious and may be due to noise and bias levels.

Dunning, Kruger, and coauthors’ latest paper on this subject comes to qualitatively similar conclusions after making some attempt to test alternative explanations

via Illusory superiority

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