Famous People With Average IQ: Success Beyond the Score

Why these old scores are unreliable

Before you draw any conclusion from a celebrity IQ figure, weigh how it was produced. Almost every historical score has at least one of these problems.

• Age and ceiling effects. Feynman likely sat a paper-and-pencil school test around 1930, at roughly age 12 or 13. Early-20th-century school tests leaned verbal, had low ceilings that could not register exceptional ability, and were taken years before the brain finishes maturing. His later performance (the highest score in the country on the Putnam exam, record graduate-admission marks at Princeton) is impossible to square with a hard cap at 125.
• Percentile-to-IQ conversion errors. Ali reportedly scored at the 16th percentile on the Army test. On a standard scale (mean 100, standard deviation 15), the 16th percentile is about IQ 85, not 78. Somewhere along the way the numbers were garbled and then copied for decades. Ali was also dyslexic and disliked reading, which drags down performance on a timed written test regardless of underlying ability.
• Motivation and context. A draft-qualification test taken by a young man with strong reasons not to serve is not a neutral measurement. More broadly, a single bad-day, high-stakes, unfamiliar test is a snapshot, not a portrait.
• Numbers that were never tests. As with Warhol, many "IQs" of the famous are estimates, jokes, or fan math worked backward from achievement. They are opinions dressed as data.

The honest takeaway is not "these people were secretly geniuses so the story still favors high IQ." It is simpler: old scores are noisy, and no single number, high or low, captures a person.

What the research actually says about IQ and success

Here is the part that should genuinely change how you read your own score. IQ does predict some outcomes, but it leaves the majority of real-world success unexplained.

• Job performance. Across decades of meta-analysis (Schmidt and Hunter), general mental ability is among the best single predictors of job performance, correlating around 0.5. But even that leaves roughly two-thirds to three-quarters of the variation in performance to other factors, and the strength depends heavily on how complex the job is.
• Income. When income is averaged over several years, its correlation with IQ is about 0.36, meaning IQ statistically accounts for only around 13 percent of the differences in what people earn. The rest is drive, opportunity, field, connections, timing, and luck.
• The Terman study. Psychologist Lewis Terman tracked more than 1,000 high-IQ children ("Termites") for decades expecting a generation of leaders. Some became distinguished professionals; others became clerks, police officers, and tradespeople. Terman himself concluded that "intellect and achievement are far from perfectly correlated." What best separated the high achievers was not IQ but perseverance, self-confidence, and goal-directedness.
• Grit. Angela Duckworth's research found that grit (sustained passion and persistence toward long-term goals) predicted success at West Point, in the National Spelling Bee, and among Ivy League students, and did so independently of IQ. Grit did not correlate positively with intelligence at all.

Put plainly: intelligence is a real advantage, but it is one lever among many. Creativity, temperament, relentlessness, health, timing, and circumstance do enormous work, and none of them show up on an IQ test.

The empowering takeaway: IQ is not destiny

If you have ever taken a test and felt boxed in by the result, hold these facts together. A future Nobel laureate scored 125 as a boy. A legendary champion and orator was saddled with a reported score in the 70s that almost certainly understated him. The most celebrated pop artist of his century carried an invented "85" as a punchline he seemed to enjoy. In every case the number was the least interesting thing about the person.

A test score is a snapshot of certain reasoning skills on a certain day, calibrated so that the average is 100. It is not a prophecy, a ceiling, or a measure of your worth, your creativity, or how far effort can carry you. If your result came back "average," you sit in the widest, most capable part of the human range, alongside people who have built companies, won titles, and changed how the rest of us see the world.

FAQ

Q: Did successful people really have average IQ scores?

A: Yes, and it is well documented. Richard Feynman scored about 125 on a school IQ test, Muhammad Ali was reported to score around 78 (roughly the 16th percentile) on a 1964 Army test, and Andy Warhol's famous "85" was a Gore Vidal quip rather than a real measurement. Ordinary or low measured scores clearly did not stop any of them.

Q: Was Feynman's IQ really only 125?

A: That was his school-age score, and it almost certainly understated him. The test was taken around age 12-13, leaned verbal, and had a low ceiling. Feynman later posted the top score in the country on the Putnam math competition, which no true cap of 125 could explain. It is a good example of why old scores should be read loosely.

Q: How much does IQ actually predict success?

A: Some, but far less than people assume. IQ correlates around 0.5 with job performance and about 0.36 with income (roughly 13 percent of income differences). The remaining majority is explained by non-cognitive factors like persistence, personality, opportunity, and luck, which is why Terman and Duckworth both found grit and drive mattered enormously.

Q: Should I be discouraged by an average IQ score?

A: No. An average score places you in the largest and most capable segment of the population, the same band as many highly accomplished people. A test measures certain reasoning skills on one day; it does not measure creativity, effort, or your potential. Use it as one data point, not a verdict.

References

• Gleick, J. (1992). Genius: The Life and Science of Richard Feynman. Pantheon Books. (Source of the 125 school score.)
• Duckworth, A. L., Peterson, C., Matthews, M. D., & Kelly, D. R. (2007). Grit: Perseverance and passion for long-term goals. Journal of Personality and Social Psychology, 92(6), 1087-1101.
• Schmidt, F. L., & Hunter, J. E. (1998). The validity and utility of selection methods in personnel psychology. Psychological Bulletin, 124(2), 262-274.
• Terman, L. M., & Oden, M. H. (1959). Genetic Studies of Genius, Vol. V: The Gifted Group at Mid-Life. Stanford University Press.

Last updated: July 13, 2026