In the field of social psychology, illusory superiority is a condition of cognitive bias wherein a person overestimates their own qualities and abilities, in relation to the same qualities and abilities of other people. Illusory superiority is one of many positive illusions, relating to the self, that are evident in the study of intelligence, the effective performance of tasks and tests, and the possession of desirable personal characteristics and personality traits.
The term illusory superiority was first used by the researchers Van Yperen and Buunk, in 1991. The phenomenon is also known as the above-average effect, the superiority bias, the leniency error, the sense of relative superiority, the primus inter pares effect, and the Lake Wobegon effect, named after the fictional town where all the children are above average.
A vast majority of the literature on illusory superiority originates from studies on participants in the United States. However, research that only investigates the effects in one specific population is severely limited as this may not be a true representation of human psychology. More recent research investigating self-esteem in other countries suggests that illusory superiority depends on culture. Some studies indicate that East Asians tend to underestimate their own abilities in order to improve themselves and get along with others.