The psychologists who built IQ, and their own estimated IQs

Francis Galton has the highest estimate among the 11 psychologists here, 180+. Ironically, almost none of the people who invented intelligence testing ever published their own score, so these figures are estimates; each profile also explains the part of the IQ test that person created.

Francis Galton: 180+. What's yours?

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Updated October 2026 · Every number links to a sourced profile

All 11, ranked

#	Name	Basis	Confidence	Range	Estimate
1	Francis Galton Polymath & Statistician, 1822 to 1911	Terman 1917 historiometric estimate	Low	178 to 200	180+
2	William James Psychologist & Philosopher, 1842 to 1910	No documented estimate; editorial marker from the record	Very low	140 to 170	155
3	Carl Jung Psychiatrist & Psychologist	No documented estimate; editorial comparison	Very low	135 to 160	150+
4	Jean Piaget Developmental Psychologist, 1896 to 1980	No documented estimate; editorial marker from the record	Very low	135 to 165	150
5	Alfred Binet Psychologist, 1857 to 1911	No documented estimate; editorial marker from the record	Very low	130 to 160	145
6	B. F. Skinner Behavioural Psychologist, 1904 to 1990	No documented estimate; editorial marker from the record	Very low	130 to 160	145
7	Charles Spearman Psychologist & Statistician, 1863 to 1945	No documented estimate; editorial marker from the record	Very low	130 to 160	145
8	Ivan Pavlov Physiologist, 1849 to 1936	No documented estimate; editorial marker from the record	Very low	130 to 160	145
9	David Wechsler Psychologist, 1896 to 1981	No documented estimate; editorial marker from the record	Very low	125 to 155	140
10	Lewis Terman Psychologist, 1877 to 1956	No documented estimate; editorial marker from the record	Very low	125 to 155	140
11	Sigmund Freud Father of Psychoanalysis	No documented estimate; editorial comparison	Very low	125 to 150	140+

Estimate: the working figure on each profile, with its range. None is a measured test score unless the basis says so.

About this list

Every number on this site rests on ideas these people developed. Francis Galton first tried to measure intelligence; Alfred Binet built the first practical test in 1905; Lewis Terman turned it into the Stanford-Binet and the IQ score in 1916; Charles Spearman found the general factor, g, that all good tests measure; David Wechsler replaced mental age with the mean-100, SD-15 scale used today. Terman also directed Catharine Cox's 1926 study of historical geniuses, the source of most famous historical IQs.

Their own estimates follow the same rules as everyone else's. Galton has a figure from Terman's own 1917 analysis of his childhood; the others have editorial markers built from the documented record, labelled with very low confidence.

How would you score?

Where would you land next to Francis Galton?

Francis Galton's 180+ is an estimate from the historical record, with a working range of 178 to 200. On the standard IQ scale an IQ of 180 sits at the 99.9999951st percentile: about 1 in 21 million people score that high. Nobody can test Francis Galton now. You can find out where you sit on the same scale.

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How a modern IQ score is made

A modern IQ is a comparison, not a quantity. Your raw score is compared with a large sample of people your age, and the result is scaled so that the average is 100 and the standard deviation is 15. That is Wechsler's deviation IQ. A score of 130 means about two standard deviations above average, higher than roughly 98 percent of people.

The items on good tests are chosen because they load on Spearman's g. Matrix puzzles, where you find the missing piece of a visual pattern, are among the best single measures of g, which is why they appear in so many tests, including the LifeScore test.

Binet himself warned that intelligence is not fixed and that a test should help children, not label them. Terman, by contrast, promoted eugenics, and his own gifted study screened out two future Nobel physicists. The history of IQ is a history of useful tools and serious misuse, and both are part of this list.

Frequently asked questions

Who invented the IQ test?

Alfred Binet and Théodore Simon created the first practical intelligence test in France in 1905. The IQ score itself came from William Stern's ratio of mental age to age in 1912 and Lewis Terman's Stanford-Binet in 1916. David Wechsler introduced the modern deviation IQ in 1939.

What was Francis Galton's IQ?

Lewis Terman estimated about 200 for Galton's childhood in a 1917 paper, based on letters showing he read at two and a half and wrote Latin at four. On the modern scale that is far lower, and it remains an estimate from biography.

What was Freud's IQ?

Unknown. Freud never took an IQ test, and he was born in 1856, after the Cox study period. LifeScore uses an editorial marker in the 140s based on his education and writing.

Is IQ still used by psychologists today?

Yes. Tests such as the WAIS and WISC, descended from Wechsler's work, are widely used in education and assessment, and IQ remains one of the best-studied measures in psychology. Online tests give an estimate rather than a full professional assessment.

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