Illusory superiority
Also known as: Above-average effect, Lake wobegon effect, Superiority bias
Most people rate themselves as better than most people.
What it means
The pervasive tendency to overestimate one's own qualities and abilities relative to others, such that the majority rate themselves above the median on desirable traits — a statistical impossibility in aggregate. It spans driving skill, intelligence, ethics, health, and leadership, and is strongest for ambiguous, self-defined dimensions where one can choose flattering criteria. Proposed mechanisms include self-enhancement motives, egocentric focus on one's own strengths while neglecting others' details, and the difficulty of obtaining honest comparative feedback. The effect attenuates or reverses for clearly defined, difficult skills, where worse-than-average beliefs emerge. It is central to overconfidence, resistance to coaching, and miscalibrated risk-taking.
Examples
In a classic survey, about 90% of drivers rated their skill as above average; most cannot literally be in the top half.
Ask any team privately and almost everyone puts themselves in the top half of performers. The arithmetic guarantees that review season leaves a lot of people feeling robbed.
Almost nobody thinks they are a below-average friend — partly because everyone quietly defines 'good friend' as whatever they happen to be good at, remembering birthdays or turning up in a crisis.
First described in Svenson (1981); College Board self-survey (1976).