Illusory superiority

Illusory superiority is a cognitive bias whereby individuals overestimate their own qualities and abilities, 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 some people have fewer than two and none have more. 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. As subjects evaluated themselves on a specific, well-defined attribute, illusory superiority remains.

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