By Alex Fradera

A systematic survey in the US of people’s beliefs about their own intelligence – the first for 50 years – has shown that was true then is also the case in the modern era: a majority of people think they are smarter than average.

The research, led by Patrick Heck from the Geisinger Health System and published in PLOS One, combined an online survey and phone survey, with each involving 750 people reflecting a cross-section of the US population, balanced in terms of sex, age, education levels and race.

Across both surveys, 65 per cent of participants agreed with the statement “I am more intelligent than the average person.” Around 70 per cent of men versus 60 per cent of women made the above-average claim, and a similar pattern was found in the young and old. There were also no clear racial differences.

This research accords with both the half-century old study from the Russell Sage Foundation, and more recent research that suggests there is an overconfidence bias in the general population. The trouble is that most of the work following the Foundation’s study has often come from self-selecting or convenience samples that are unlikely to be representative of the wider population, or from students, who may be special cases, struggling, for instance, to envisage what the average person is like from their campus existence.

The new surveys also validate another cornerstone of overconfidence research: that the least intelligent tend to be the most overconfident. While university graduates (who are typically one standard deviation higher than average in intelligence) collectively tended to slightly underestimate their intelligence, those participants whose highest qualification was a high school diploma collectively over-shot in estimating theirs. Heck’s team conclude “that American’s self-flattering beliefs about intelligence are alive and well several decades after their discovery was first reported.”

—65% of Americans believe they are above average in intelligence: Results of two nationally representative surveys

Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest