IQ Metrics
IIF Certified Assessment Start IQ Test
IIF Certified Assessment
Start IQ Test
Data studyGenius and the history of IQ · Version 2026.10

The IQs of 301 geniuses: Cox’s 1926 estimates, in full

In 1926 Catharine Cox estimated how bright 301 of history’s most eminent people were as children, from Newton to Napoleon. Her per-person table is the source of most “historical IQ” numbers online, yet it is hard to find. Here it is in full: every estimate, how good the records were, and why the famous numbers are so high. CSV included.

By Leon Falkner, Data & Research Analyst · Reviewed by Aarav Vardhan, Editor-in-Chief · Published 26 October 2026 · 12 min read

Download data Cite this study

About this study

Report type
Data study from a published record
Data
Cox (1926), Genetic Studies of Genius Vol. II, Tables 12A and 12B, all 312 rows
Covers
301 eminent people born 1450 to 1850 with IQ estimates, plus 11 listed without one
Checked
Every row against Cox's printed totals, group means and correction formula
Licence
CC BY 4.0 (our table); the 1926 book is US public domain
Version
2026.10
Sources
5
Short answer

In 1926 Stanford psychologist Catharine Cox estimated the IQs of 301 historical geniuses, born 1450 to 1850, from records of their early lives. Her raters averaged 135 for childhood and 145 for youth. Only 9 reached 180; higher figures quoted today, such as Newton’s 190, are her “corrected” estimates.

301 geniusesBorn 1450-18501926 book, public domainCC BY 4.0
301historical geniuses with IQ estimates (Cox, 1926)
9 vs 57at 180 or more, before and after Cox's correction
+20points the correction adds on average

01 Key findings

  1. Only 9 of 301 geniuses were estimated at IQ 180 or more for ages 17 to 26; after Cox’s correction, 57 were. Famous figures such as Leonardo’s 180 and Newton’s 190 are corrected numbers.Cox (1926), Tables 12A-12B; counts by IQ Metrics
  2. The correction adds 20.1 points on average to the youth estimate, and up to 45 (Cervantes, 110 to 155). Cox called it “a crude approximation” that marks a floor.Cox (1926), p. 52 and Tables 12A-12B
  3. Thin records, low estimates: people whose records Cox rated .11 averaged 121; those rated .82 averaged 168. She reported a correlation of .77 (our recount: 0.75).Cox (1926), pp. 79-80 and Tables 12A-12B
  4. Philosophers were rated highest (youth average 156.4) and soldiers lowest (124.8). Goethe is the only person the raters put at 200; John Stuart Mill has the highest childhood estimate, 190.Cox (1926), Tables 12A-12B
  5. Shakespeare has no estimate, one of 11 people with too little recorded about their early years. Einstein, born 1879, is not in the study.Cox (1926), Table 12A and p. 33

02 Statistics to quote

301

Historical geniuses, born 1450 to 1850, given IQ estimates by Catharine Cox in 1926; 11 more were listed without one.

Cox, 1926
135 / 145

Average estimate for childhood (to 17) and youth (17 to 26) in her main group of 282.

Cox, 1926
9 vs 57

People at 180 or more on the youth estimate, before and after Cox’s correction.

IQ Metrics, from Cox 1926
+20

Points the correction adds to the youth estimate, on average (up to +45).

IQ Metrics, from Cox 1926
121 vs 168

Average youth estimate for people with the thinnest records and with the richest.

IQ Metrics, from Cox 1926
1

Person the raters put at 200: Goethe. After the correction, 4 people reach 200.

Cox, 1926

Most of the famous IQs of 180 and above in history are not what Cox’s raters estimated. They come from a correction that she herself called a crude approximation.

Leon Falkner, IQ Metrics Research

03 What did Catharine Cox do in 1926?

She tried to work out how bright the most eminent people in history had been as children. Cox, a Stanford psychologist working with Lewis Terman, took the most eminent names in J. McKeen Cattell’s 1903 list of 1,000 famous people, kept those born between 1450 and 1850 with enough recorded about their early years, and gathered every account of their childhood and youth she could find [1] [3]. The result, The Early Mental Traits of Three Hundred Geniuses, is Volume II of Genetic Studies of Genius, the series that also holds Terman’s study of gifted children [1].

Three raters, Cox, Terman and Maud Merrill, read each file and judged what IQ a child would need to do what the records said this one did at each age, against the test norms of the day [1]. Each person got two estimates: AI for development to age 17 and AII for ages 17 to 26. Cox also rated how good the evidence was, from a guess to a full record, and turned that into a reliability coefficient for each estimate. The idea came from Terman’s 1917 paper judging, from Karl Pearson’s biography, that Francis Galton had a childhood IQ “not far from 200” [4] [1].

AI and AII
The two estimates for each person: to age 17, and from 17 to 26. Each is the average of the three raters.
Reliability of the data
Cox’s rating of the evidence behind each estimate, as a coefficient from .00 (a guess) to .90 (full evidence); in her tables it runs from .00 to .82.
Corrected IQ
A second figure Cox printed for every person: the estimate pushed up toward the average of the person’s field, more so when the records were thin [1].
Group A and Group B
The main group of 282, ranked by eminence, and 19 people born mostly in the 1800s whom Cox added partly because their records were easy to reach [1].
Ratio IQ
The IQ of the 1920s: mental age divided by real age, times 100. It is not the same scale as a modern IQ score.

Why this table matters

Cox’s per-person figures sit in two fold-out tables (12A and 12B) that are missing or unreadable in the scan most websites cite. Pages that quote “the IQ of Leonardo” usually give one number with no sign of which of Cox’s four columns it came from. This page publishes all of them, for all 312 people, with a CSV.

04 How high were the estimates?

High, but mostly not the sky-high numbers seen online. In the main group of 282 the raters’ estimates averaged 135 for childhood and 145 for youth; Cox printed 134.9 and 144.7 and used 135 and 145 in her formulas [1]. Across all 301, 9 were put at 180 or more for youth and one, Goethe, at 200 [2]. The lowest youth estimate was 105 for André Masséna; the lowest childhood estimates, 100, went to Jean de La Fontaine, André Masséna and Sébastien de Vauban [2].

Figure 1

Cox's 301 geniuses before and after her "correction"

Number of people in each 10-point band of the young-adult estimate (ages 17 to 26). Left: the IQ her three raters gave. Right: the corrected figure she printed beside it, which is the one most often quoted.

Source: Cox (1926), Tables 12A and 12B, facing p. 60 [2]; counts by IQ Metrics

Table 1

Everyone the raters put at 180 or more

PersonFieldChildhoodYouthCorrected
Johann Wolfgang von Goethe (1749-1832)Poet, novelist185200190 / 210
Hugo Grotius (1583-1645)Statesman185190195 / 200
Gottfried Wilhelm Leibniz (1646-1716)Philosopher185190195 / 205
John Stuart Mill (1806-1873)Philosopher190170200 / 180
Jeremy Bentham (1748-1832)Essayist, scholar180170185 / 180
Albrecht Haller (1708-1777)Scientist175180180 / 190
Thomas Macaulay (1800-1859)Essayist, scholar180165185 / 175
Philipp Melanchthon (1497-1560)Religious leader160180170 / 190
Blaise Pascal (1623-1662)Scientist180180190 / 195
William Pitt the Younger (1759-1806)Statesman160180170 / 190
F. W. Schelling (1775-1854)Philosopher175180180 / 190
Voltaire (1694-1778)Poet, novelist170180180 / 190

Source: Cox (1926), Tables 12A and 12B [2]. Childhood = to age 17; youth = 17 to 26; corrected = childhood / youth.

The highest childhood estimate, 190, went to John Stuart Mill, who was reading Greek and studying Euclid before he was 9; Cox called his case “a striking exception” because his youth estimate (170) came out lower [1]. Cox concluded that the true average of the group lay “at a point not lower than 155 to 165 IQ” [1].

05 Why are the famous numbers so high?

Because they are usually Cox’s corrected figures, not her raters’ estimates. Cox noticed that the raters pulled toward 100 when the evidence was thin, so she pushed each estimate back up toward the average of the person’s field, by more when the records were poorer [1]. Her formula adds (field average minus 100) times (1 minus the reliability), rounded to the nearest 5. Across the 301 it adds 20.1 points to the youth estimate on average and up to 45, for 6 people with very thin records, among them Miguel de Cervantes (110 to 155) and James Cook (115 to 160) [2].

Figure 2

The 25 most eminent people in Cox's main group: estimate vs corrected figure

Young-adult estimate (ages 17 to 26). Ordered by Cox's rank of eminence, 1 = Napoleon. The gap is what her correction added; it is largest where the records were thinnest.

Estimate the raters gaveCorrected estimate

Napoleon is first because Cox kept the order of J. McKeen Cattell's 1903 ranking of eminent people.

Source: Cox (1926), Table 12A [2]; eminence order from Cattell (1903) [3]

That is where Leonardo da Vinci’s 180 comes from: his raters gave 150 for youth from records rated .20, and the correction lifted it to 180. Isaac Newton went from 170 to 190, Michelangelo from 160 to 180 [2]. On the raters’ own estimates only 9 people reach 180; on the corrected figures, 57 do, and 4 reach 200 (Johann Wolfgang von Goethe 210, Gottfried Wilhelm Leibniz 205, Hugo Grotius 200, Thomas Wolsey 200).

Figure 3

Where the correction moved Cox's 301 geniuses

Young-adult estimate (ages 17 to 26). Left: the band the raters' estimate fell in. Right: the band of the corrected figure. Nobody moves down; most move up a band. Hover or tap a ribbon.

Source: Cox (1926), Tables 12A and 12B [2]; counts by IQ Metrics

The correction only ever adds. 243 of the 301 people (81%) gain between 10 and 30 points, and the largest jumps go to the people with the thinnest records [2].

Figure 4

How many points the correction added, person by person

Corrected minus estimated IQ, young-adult estimate, all 301. Every correction is upward; the thinner the record, the bigger it is.

Source: Cox (1926), Tables 12A and 12B [2]; differences by IQ Metrics

The correction attempted in the present report is a crude approximation to such a true IQ: it indicates a point below which the true IQ probably did not fall.

Catharine Cox, 1926, p. 52

Cox added that the corrected figures were “not to furnish exact values for the score of an individual or even of a group” but to show the region of the scale where the true score might lie [1]. Quoting a corrected figure as “the IQ of” one person goes further than she did.

06 Did better records mean higher IQ estimates?

Yes, strongly. People with the thinnest records (reliability .11) averaged 121 on the youth estimate; those with the richest (.82) averaged 168 [2]. Cox found the same link herself and called it “entirely unexpected”: she reported a correlation of .77 between the youth estimate and the reliability of the data, and .76 with eminence held constant [1]. Recomputed from her table, our figure for the main group is 0.75.

Figure 5

The more was written about a childhood, the higher the IQ estimate

Young-adult estimates of all 301, grouped by how reliable Cox judged the records (0 = a guess, 1 = full evidence). Box = middle half; line = median; whiskers = lowest and highest. Hover or tap a dot for the person.

Reliability of the records, as Cox rated it, for ages 17 to 26.. Dotted line: Cox's group mean, 145.

Source: Cox (1926), Tables 12A and 12B [2]; quartiles by IQ Metrics

The link cuts both ways. Bright children may leave more of a paper trail, because families keep their letters and biographers repeat their feats. But an estimate built from a rich record also has more to go on, and Cox’s raters admitted they pulled toward 100 when the evidence was weak [1]. Either way, a high number in this table says as much about the archive as about the child.

Time shows the same pattern. People born in the 1700s and 1800s have fuller records and higher estimates than those born in the 1400s and 1500s, and so their corrections are smaller [2].

Figure 6

Later-born geniuses got higher estimates, and smaller corrections

Main group (282), by century of birth. Young-adult estimate. Records improve over time, so the raters' figures rise and the correction shrinks.

Estimate the raters gaveCorrected estimate

"Records" = Cox's average reliability rating of the data for that period (0 to 1).

Source: Cox (1926), Table 12A [2]; Cox’s own period means: Table 20A, p. 83 [1]

Put every measure side by side and the records stand out again. The youth estimate tracks the quality of the records (0.75) far more than it tracks fame: its correlation with Cox’s eminence rank is only 0.23. And there is no sign that the brightest lived longest: the correlation between the youth estimate and length of life is 0.01 [2].

Figure 7

What goes with a high estimate? Every pair, in one matrix

Pearson correlations, main group (282 people with both dates). Blue = go up together, warm = one up, one down. Linked, not cause.

Source: Cox (1926), Table 12A [2]; correlations by IQ Metrics

07 Which fields had the highest estimates?

Philosophers had the highest average youth estimate (156.4, 22 people) and soldiers the lowest (124.8, 29 people) [2]. Of soldiers and artists Cox wrote that “the records are very inadequate” [1], and both gain the most from her correction. Artists had the lowest childhood estimates of all (122.3).

Figure 8

Average estimate by field, before and after the correction

Young-adult estimate (ages 17 to 26), all 301. The correction pulls each person toward the average of his or her own field, so fields with thin records (artists, soldiers) gain the most.

Estimate the raters gaveCorrected estimate

Source: Cox (1926), Tables 12A and 12B [2]; means by IQ Metrics (Cox’s own field means: Tables 20A and 20B, pp. 83-84 [1])

Averages hide a wide spread. Poets, novelists and dramatists run from 110 to 200 and statesmen from 110 to 190, while no soldier was rated above 145. The gaps between fields also shift with the century of birth, partly because some fields have few early-born members with good records [2].

Figure 9

The spread of estimates inside each field

Young-adult estimate. Each dot is one person; the shape shows where estimates bunch; the navy tick is the median; the orange diamond is the field's corrected average.

Source: Cox (1926), Tables 12A and 12B [2]

Figure 10

Average estimate by field and century of birth

Young-adult estimate, main group (282). Blank = fewer than 3 people in that cell. Darker = higher.

Source: Cox (1926), Table 12A [2]; means by IQ Metrics

08 Did the estimates rise between childhood and youth?

Usually. The youth estimate is higher by 9.7 points on average, the same for 52 people and lower for 15 [2]. Cox put the rise down to fuller records after 17, not to the people getting brighter [1]. The biggest jumps belong to late starters with thin childhood records: Michael Faraday, a bookbinder’s apprentice, went from 105 to 150, and Newton from 130 to 170. Nicolaus Copernicus has a childhood estimate of just 105 [2].

Figure 11

Childhood to youth: how the estimates changed for the 25 most eminent

Each line is one person: the childhood estimate (to 17) and the youth estimate (17 to 26). Coloured: the biggest rises.

Biggest risesOthers

Source: Cox (1926), Table 12A [2]

Table 2

Biggest changes from the childhood to the young-adult estimate

PersonChildhood (to 17)Youth (17 to 26)Change
Michael Faraday105150+45
Justus Liebig125165+40
Isaac Newton130170+40
Raphael110150+40
J. J. Scaliger120155+35
Francis Atterbury120150+30
Victor Cousin135165+30
J. L. Gay-Lussac125155+30
John Stuart Mill190170-20
Thomas Macaulay180165-15
Jeremy Bentham180170-10
S. T. Coleridge175165-10

Source: Cox (1926), Tables 12A and 12B [2]. Highlighted: the largest falls.

09 What was the estimated IQ of a famous person?

Pick any of the 312 people in Cox’s tables. Each card gives both estimates, how reliable Cox judged the records and her corrected figures, with a link and a share image. Our longer profiles cover Abraham Lincoln, Benjamin Franklin, Blaise Pascal, Charles Darwin, Galileo Galilei, George Washington, Isaac Newton, Johann Wolfgang von Goethe, Ludwig van Beethoven, Napoleon Bonaparte, Thomas Jefferson, Voltaire, William Shakespeare, Wolfgang Amadeus Mozart.

Youth IQ170

Estimated IQ 130 to 170

Scientist · English · eminence rank 7 of 282

Childhood (to 17)records .43
130
Youth (17 to 26)records .60
170
CorrectedCox's floor, not a score
150 / 190
Eminence rankCox's order
7 of 282

In 1926 Catharine Cox's raters estimated the IQ of Isaac Newton (1642-1727) at 130 for childhood (to age 17) and 170 for youth (17 to 26), from records Cox rated .43 and .60 for reliability (1 = full evidence). Her corrected figures, often quoted instead, are 150 and 190.

How to read it: each number is an average of three raters’ judgments from written records, not a test score. “Records” is how reliable Cox judged the evidence, from 0 (a guess) to 1. The corrected figure is her estimate of a floor for the true IQ, which she said should not be read as an exact value for one person [1].

A 1926 estimate from a biography says nothing about you. See where your own reasoning stands: take the IQ test 

10 Who is missing from Cox's list?

Eleven people in her tables have no estimate at all, William Shakespeare and Niccolò Machiavelli among them, because too little was known about their early years [2]. Anyone born after 1850 is out by design, so Albert Einstein (born 1879), Marie Curie and Nikola Tesla are not in the study; figures quoted for them have other origins. People born before 1450 and, in Cox’s words, the hereditary aristocracy and nobility were also left out [1].

Table 3

The 11 people Cox listed but could not rate

PersonWhat Cox printed in place of the estimates
Luiz Vaz de Camoëns(Insufficient or no data on early years)
J. B. Colbert(Insufficient or no data on early years)
Étienne B. de Condillac(Insufficient or no data on early years)
John Knox(Insufficient or no data on early years)
A. R. Le Sage(Insufficient or no data on early years)
Ignatius Loyola(Insufficient or no data on early years)
Niccolò Machiavelli(Insufficient or no data on early years)
F. Pizarro(Insufficient or no data on early years)
F. Rabelais(Insufficient or no data on early years)
William Shakespeare(Insufficient or no data on early years)
Titian(Insufficient or no data on early years)

Source: Cox (1926), Table 12A [2]

11 The full table

Every person in Tables 12A and 12B, sortable. Click a column heading to sort. The CSV adds each estimate’s probable error, the reliability grade, Cox’s eminence rank and her trait-rating reliability.

Table 4

All 312 people in Cox's tables

Adams, John (1735-1826)Statesman120145.75155
Adams, John Quincy (1767-1848)Statesman165165.82175
Addison, Joseph (1672-1719)Essayist, scholar125140.53165
Agassiz, J. Louis (1807-1873)Scientist140160.75175
Alberoni, Guilio (1664-1752)Statesman110110.11145
Alfieri, Vittorio (1749-1803)Poet, novelist135135.53160
Ali Weli Zade (1741-1822)Statesman120120.11155
Anderson, Hans Christian (1805-1875) (B)Poet, novelist115125.60145
Andrewes, Lancelot (1555-1626)Religious leader135140.60160
Arago, D. F. (1786-1853)Scientist145165.75180
Ariosto, Ludovico (1474-1533)Poet, novelist125135.53160
Arnauld, Antoine (1612-1694)Philosopher135160.43190
Atterbury, Francis (1662-1732)Religious leader120150.60170
Bach, J. Sebastian (1685-1750)Musician125140.43165
Bacon, Francis (1561-1626)Philosopher145155.53180
Bailly, J. S. (1736-1793)Scientist145160.60180
Balzac, Honoré de (1799-1850)Poet, novelist130145.75155
Baxter, Richard (1615-1691)Religious leader135135.60155
Bayle, Pierre (1647-1706)Essayist, scholar135140.53165
Beaumarchais, Pierre A. C. de (1732-1799)Poet, novelist140145.60165
Beethoven, Ludwig van (1770-1827)Musician135140.43165
Bentham, Jeremy (1748-1832)Essayist, scholar180170.82180
Bentley, Richard (1662-1742)Essayist, scholar140150.60170
Béranger, Pierre Jean de (1780-1857)Poet, novelist115130.53155
Berkeley, George (1685-1753)Philosopher150175.75190
Bernadotte (Charles XIV) (1763-1844)Soldier115120.20140
Berzelius, John Jacob (1779-1848)Scientist120140.60160
Beza, Théodore de (1519-1605)Religious leader125140.43165
Bichat, Marie François (1771-1802)Scientist140150.53175
Blake, Robert (1599-1657)Soldier125130.20150
Blücher, Gebhard L. von (1742-1819)Soldier110125.20145
Boerhaave, Hermann (1668-1738)Scientist140150.75165
Bolivar, Simon (1783-1830)Soldier125135.20155
Bossuet, Jacques B. (1627-1704)Religious leader160160.53180
Boyle, Robert (1626-1691)Scientist140140.60160
Bright, John (1811-1889)Statesman125130.53150
Brontë, Charlotte (1816-1855) (B)Poet, novelist155155.82165
Brougham, Henry P. (1778-1868)Statesman160170.75180
Buffon, Comte de (G. L. Leclerc) (1707-1788)Scientist125130.11175
Bulwer-Lytton, Edward G. (1803-1873)Poet, novelist140145.75155
Bunsen, Christian K. J. (1791-1860)Essayist, scholar150165.82175
Bunyan, John (1628-1688)Essayist, scholar105120.20160
Burke, Edmund (1729?-1797)Statesman135150.60165
Burnet, Thomas (1643-1715)Essayist, scholar145145.60165
Burns, Robert (1759-1796)Poet, novelist130130.60150
Byron, Lord (George Gordon) (1788-1824)Poet, novelist150170.82180
Calderón, de la Barca, Pedro (1600-1681)Poet, novelist140140.43170
Calvin, John (1509-1564)Religious leader135150.43175
Camoëns, Luiz Vaz de–––––
Campanella, Tommaso (1568-1639)Philosopher145155.43185
Candolle, A. P. de (1778-1841)Scientist140150.60170
Canning, George (1770-1827)Statesman150155.82165
Canova, Antonio (1757-1822)Artist130140.43160
Cardan, Jerome (1501-1576)Scientist135155.60175
Carlyle, Thomas (1795-1881)Essayist, scholar140155.75165
Carnot, Lazare (1753-1823)Statesman150150.53170
Cavour, Camillo B., Count di (1810-1861)Revolutionary150150.82160
Cervantes, Miguel de (1547-1616)Poet, novelist105110.11155
Chalmers, Thomas (1780-1847)Religious leader145160.75170
Channing, William E. (1780-1842)Religious leader145150.75160
Chateaubriand, F. R. A., Vicomte de (1768-1848)Poet, novelist150150.75160
Chatterton, Thomas (1752-1770)Poet, novelist170170.75180
Chesterfield, Earl of (P. D. Stanhope) (1694-1773)Essayist, scholar125135.53160
Clarendon, Earl of (George Villiers) (1800-1870) (B)Statesman120125.20160
Clarke, Samuel (1675-1729)Religious leader135140.53160
Clive, Robert (1725-1774)Soldier110120.20140
Cobbett, William (1763?-1835)Essayist, scholar105125.43150
Cobden, Richard (1804-1865)Statesman120120.20155
Colbert, J. B.–––––
Coleridge, S. T. (1772-1834)Poet, novelist175165.75175
Comte, I. A. (1798-1857)Philosopher150170.75185
Condillac, Étienne B. de–––––
Condorcet, Marq. de (M.J.A.N. Caritat) (1743-1794)Philosopher155165.75180
Constant, de Rebecque, H. B. (1767-1830)Statesman165160.75170
Cook, James (1728-1779)Scientist105115.11160
Copernicus, Nicolas (1473-1543)Scientist105130.43160
Corneille, Pierre (1606-1684)Poet, novelist130140.60160
Cortez, Hernando (1485-1547)Soldier115120.20140
Cousin, Victor (1792-1867)Philosopher135165.75180
Cowper, William (1731-1800)Poet, novelist135140.60160
Cranmer, Thomas (1489-1556)Religious leader120130.20165
Cromwell, Oliver (1599-1659)Soldier110115.20135
Cuvier, Georges L. (1769-1832)Scientist155160.75175
D’Alembert, J. P. le R. (1717-1783)Scientist150165.60185
Danton, Georges J. (1759-1794)Revolutionary145145.75155
Darwin, Charles R. (1809-1882)Scientist135140.53165
Davy, Humphry (1778-1829)Scientist150175.82185
De Foe, Daniel (1659 or 1660-1731)Poet, novelist120125.20165
Descartes, René (1596-1650)Philosopher150160.60180
Dickens, Charles (1812-1870)Poet, novelist145155.53180
Diderot, Denis (1713-1784)Essayist, scholar150145.60165
Disraeli, Benjamin (1804-1881)Statesman145150.60165
Drake, Francis (1545?-1596)Soldier105110.11130
Dryden, John (1631-1700)Poet, novelist125130.43160
Dumas, Alexandre (Père) (1802-1870)Poet, novelist140150.60170
Dupin, A. M. J. J. (1783-1865)Statesman120140.53160
Dürer, Albrecht (1471-1528)Artist125135.43155
Eliot, George (Mary Ann Evans) (1819-1880) (B)Poet, novelist150150.75160
Emerson, Ralph Waldo (1803-1882)Essayist, scholar145145.75155
Erasmus, Desiderius (1467?-1536)Religious leader135140.11180
Étienne, Charles G. (1778-1845)Poet, novelist135140.60160
Faraday, Michael (1791-1867)Scientist105150.60170
Farragut, David G. (1801-1870)Soldier120120.43135
Fénelon, François (1651-1715)Religious leader145145.20180
Fichte, Johann G. (1762-1814)Philosopher145155.75170
Fielding, Henry (1707-1754)Poet, novelist120135.43165
Fouché, Joseph (1759?-1820)Revolutionary125130.20165
Fox, Charles James (1749-1806)Statesman145145.75155
Fox, George (1624-1690)Religious leader110120.20155
Franklin, Benjamin (1706-1790)Statesman145145.60160
Franklin, John (1786-1847)Scientist135135.75150
Fulton, Robert (1765-1815) (B)Scientist105115.20155
Galileo Galilei (1564-1642)Scientist145165.60185
Gambetta, Leon Michel (1838-1882) (B)Statesman140140.60155
Garibaldi, Giuseppe (1807-1882)Soldier120125.43140
Garrison, William Lloyd (1805-1879) (B)Statesman115130.60145
Gaskell, E. C. S. (1810-1865) (B)Poet, novelist110115.11160
Gassendi, Pierre (1592-1655)Scientist150160.53185
Gay-Lussac, J. L. (1778-1850)Scientist125155.60175
Gibbon, Edward (1737-1794)Essayist, scholar145155.53180
Gluck, Christopher (1714-1787)Musician110115.20145
Goethe, J. W. (1749-1832)Poet, novelist185200.82210
Goldsmith, Oliver (1728-1774)Poet, novelist115115.60135
Grant, U. S. (1822-1885)Soldier110125.75130
Grimm, Jakob L. (1785-1863)Essayist, scholar135140.60160
Grote, George (1794-1871)Essayist, scholar135140.60160
Grotius, Hugo (1583-1645)Statesman185190.75200
Guicciardini, Francesco (1483-1540)Essayist, scholar120140.43165
Guizot, François P. G. (1787-1874)Essayist, scholar135155.75165
Haller, Albrecht (1708-1777)Scientist175180.82190
Hamilton, Alexander (1757-1804)Statesman135140.60155
Hamilton, William (1788-1856)Philosopher140160.82170
Handel, George F. (1685-1759)Musician145155.60170
Harvey, William (1578-1657)Scientist120150.43180
Hastings, Warren (1732-1818)Statesman135140.43165
Hawthorne, Nathaniel (1804-1864) (B)Poet, novelist140135.60155
Haydn, Joseph (1732-1809)Musician120140.53160
Hegel, G. W. F. (1770-1831)Philosopher150145.60165
Heine, Heinrich (1797?-1856)Poet, novelist130145.60165
Helvetius, C. A. (1715-1771)Essayist, scholar125135.43160
Herder, J. G. (1744-1803)Essayist, scholar130155.75165
Herschel, William (1738-1822)Scientist145140.53165
Hobbes, Thomas (1588-1679)Philosopher140135.43165
Hogarth, William (1697-1764)Artist110115.11145
Holberg, Ludwig von (1684-1754) (B)Poet, novelist120135.43165
Hugo, Victor (1802-1885)Poet, novelist150170.82180
Humboldt, Alexander von (1769-1859)Scientist140170.75185
Humboldt, Wilhelm von (1767-1835)Essayist, scholar145165.75175
Hume, David (1711-1776)Philosopher155160.60180
Hunter, John (1728-1793)Scientist110130.43160
Huygens, Christian (1629-1695)Scientist130150.53175
Irving, Washington (1783-1859)Essayist, scholar130145.43170
Jackson, Andrew (1767-1845)Soldier110130.43145
Jansen, Cornelis (1585-1638)Religious leader110140.53160
Jefferson, Thomas (1743-1826)Statesman145150.75160
Jenner, Edward (1749-1823)Scientist125145.60165
Johnson, Samuel (1709-1784)Essayist, scholar155155.75165
Jonson, Ben (1573-1637)Poet, novelist120145.43175
Kant, Immanuel (1724-1804)Philosopher135145.43175
Kepler, Johann (1571-1630)Scientist140160.75175
Klopstock, F. G. (1724-1803)Poet, novelist135155.75165
Knox, John–––––
Kotzebue, August von (1761-1819)Poet, novelist145150.60170
L’Hôpital, Michel de (1505-1573)Statesman115135.43160
La Fontaine, Jean de (1621-1695)Poet, novelist100125.43155
Lagrange, J. L., Comte (1736-1813)Scientist135165.60185
Lamartine, Alphonse de (1790-1869)Poet, novelist135150.82160
Lamennais, F. R. de (1782-1854)Essayist, scholar150155.60175
Laplace, Pierre Simon (1749-1827)Scientist145170.60190
Lavoisier, A. L. (1743-1794)Scientist120150.60170
Law, John (1671-1729)Statesman140140.43165
Le Sage, A. R.–––––
Lee, Robert E. (1807-1870) (B)Soldier130130.53140
Leibnitz, G. W. (1646-1716)Philosopher185190.75205
Leopardi, Giacomo (1798-1837)Poet, novelist170175.75185
Lessing, G. E. (1729-1781)Poet, novelist135150.75160
Liebig, Justus (1803-1873)Scientist125165.75180
Lincoln, Abraham (1809-1865)Statesman125140.75150
Linnæus, Carolus (1707-1778)Scientist125145.60165
Livingstone, David (1813-1873) (B)Scientist135140.43170
Locke, John (1632-1704)Philosopher125135.43165
Longfellow, H. W. (1807-1882)Poet, novelist150160.75170
Loyola, Ignatius–––––
Luther, Martin (1483-1546)Religious leader115145.43170
Macaulay, Thomas (1800-1859)Essayist, scholar180165.75175
Machiavelli, Niccolò–––––
Madison, James (1751-1836)Statesman120135.43160
Maintenon, Mme. de (F. d’Aubigné) (1635-1719)Statesman120130.43155
Malebranche, Nicolas (1638-1715)Philosopher125135.20180
Marat, Jean Paul (1743-1793)Revolutionary130130.11170
Marlborough, Duke of (J. Churchill) (1650-1722)Soldier120125.20145
Marmont, A. F. L. (1774-1852)Soldier125135.43150
Martineau, Harriet (1802-1876) (B)Essayist, scholar140140.60160
Masséna, André (1758-1817)Soldier100105.11125
Mazarin, Jules (1602-1661)Statesman130135.43160
Mazzini, Giuseppe (1805-1872)Revolutionary135145.53165
Mehemet Ali (1769-1849)Statesman105110.11145
Melanchthon, Philipp (1497-1560)Religious leader160180.75190
Mendelssohn, Felix (1809-1847)Musician150155.75165
Metastasio (P. A. D. B. Trapassi) (1698-1782)Poet, novelist145145.53170
Michelangelo (1475?-1564)Artist145160.43180
Mill, John Stuart (1806-1873)Philosopher190170.82180
Miller, Hugh (1802-1856) (B)Scientist135130.53155
Milton, John (1608-1674)Poet, novelist145170.82180
Mirabeau, G. H. V. Requetti de (1749-1791)Revolutionary165175.75185
Molière (J. B. Poquelin) (1622-1673)Poet, novelist130130.43160
Monk, George (1608-1670)Soldier110120.11140
Montaigne, Michel E. de (1533-1592)Essayist, scholar140140.43165
Montesquieu, Baron de (C. de Secondat) (1689-1755)Essayist, scholar135140.43165
Moore, Tom (1779-1852)Poet, novelist140140.75150
More, Thomas (1478-1535)Statesman135135.53155
Moreau, J. V. M. (1763-1813)Soldier110125.20145
Mozart, W. A. (1756-1791)Musician150155.75165
Murat, Joachim (1767-1815)Soldier115120.43135
Murillo, Bartolomé (1617-1682)Artist110120.11150
Musset, Alfred de (1810-1857)Poet, novelist160170.82180
Napier, John (1550-1617)Scientist125125.11170
Napoleon Bonaparte (1769-1821)Soldier135140.75145
Necker, Jacques (1732-1804)Statesman115120.11155
Nelson, Horatio (1758-1805)Soldier125145.75150
Newman, John Henry (1801-1890) (B)Religious leader155155.75165
Newton, Isaac (1642-1727)Scientist130170.60190
Ney, Michel (1769-1815)Soldier110120.43135
Niebuhr, B. G. (1776-1831)Essayist, scholar165175.75185
O’Connell, Daniel (1775-1847)Revolutionary145145.75155
Oersted, Hans Christian (1777-1851) (B)Scientist140160.60180
Palestrina, G. P. da (1525-1594)Musician110120.11155
Pascal, Blaise (1623-1662)Scientist180180.75195
Peel, Robert (1788-1850)Statesman155170.75180
Penn, William (1644-1718)Religious leader135150.60170
Pitt, William (Earl of Chatham) (1708-1778)Statesman140140.60155
Pitt, William (the Younger) (1759-1806)Statesman160180.82190
Pizarro, F.–––––
Pope, Alexander (1688-1744)Poet, novelist160170.82180
Poussin, Nicolas (1594-1665)Artist105115.11145
Prescott, W. H. (1796-1859)Essayist, scholar130135.60155
Priestley, Joseph (1733-1804)Scientist140150.75165
Rabelais, F.–––––
Racine, Jean (1639-1699)Poet, novelist135150.60170
Raleigh, Walter (1552-1618)Statesman130130.11165
Raphael Sanzio (1483-1520)Artist110150.43170
Rembrandt, H. (1606-1669)Artist110135.43155
Renan, Ernest (1823-1892)Essayist, scholar150160.75170
Reuchlin, Johann (1455-1522)Essayist, scholar120150.60170
Reynolds, Joshua (1723-1792)Artist125125.43145
Richelieu, Duc de (A. J. du Plessis) (1585-1642)Statesman120135.43160
Robertson, William (1721-1793)Essayist, scholar135140.43165
Robespierre, M. M. I. de (1758-1794)Revolutionary135145.43170
Rossini, G. A. (1792-1868)Musician120130.60145
Rousseau, J. J. (1712-1778)Essayist, scholar130125.53150
Rubens, Peter Paul (1577-1640)Artist140140.43160
Sainte-Beuve, C. A. (1804-1869)Essayist, scholar145155.75165
Sand, George (Aurore Dupin) (1804-1876)Poet, novelist150150.75160
Sarpi, Pietro (1552-1623)Essayist, scholar165175.60195
Savonarola, Girolamo (1452-1498)Religious leader130135.53155
Scaliger, J. J. (1540-1609)Essayist, scholar120155.53180
Schelling, F. W. (1775-1854)Philosopher175180.82190
Schiller, J. C. Friederich (1759-1805)Poet, novelist140155.75165
Schleiermacher, F. (1768-1834)Philosopher150145.75160
Scott, Walter (1771-1832)Poet, novelist150155.82165
Sévigné, Mme. de (Marie de Rabutin-Chantal) (1626-1696)Essayist, scholar125135.43160
Seward, W. H. (1801-1872)Statesman140140.60155
Shaftesbury, A. A. (1621-1683)Statesman125130.20165
Shakespeare, William–––––
Sheridan, P. H. (1831-1888) (B)Soldier110125.60135
Sheridan, R. B. (1751-1816)Poet, novelist130145.60165
Sherman, William T. (1820-1891)Soldier125135.60145
Smith, Adam (1723-1790)Essayist, scholar135145.53170
Soult, Nicolas J. de D. (1769-1851)Soldier115130.20150
Southey, Robert (1774-1843) (B)Poet, novelist155155.60175
Spenser, Edmund (1552-1599)Poet, novelist135145.43175
Spinoza, B. (1632-1677)Philosopher130145.43175
St. Cyr, Gouvion (1764-1830)Soldier105115.11135
St. Simon, C. H. (1760-1825)Philosopher130135.43165
Staël-Holstein, Mme. de (Germaine Necker) (1766-1817)Essayist, scholar155160.60180
Strauss, D. F. (1808-1874)Religious leader140160.75170
Sumner, Charles (1811-1874) (B)Statesman140145.60160
Swedenborg, Emanuel (1688-1772)Religious leader115145.53165
Swift, Jonathan (1667-1745)Essayist, scholar125130.53155
Tasso, Torquato (1544-1595)Poet, novelist160155.53180
Temple, William (1628-1699)Statesman130120.11155
Tennyson, Alfred (1809-1892)Poet, novelist155160.82170
Thackeray, W. M. (1811-1863)Poet, novelist135140.75150
Thiers, Louis A. (1797-1877)Statesman120140.53160
Thou, J. A. de (1553-1617)Essayist, scholar125135.20175
Tieck, Ludwig (1773-1853)Poet, novelist155155.75165
Titian–––––
Turgot, Robert Jacques (1727-1781)Statesman140160.75170
Van Dyck, Anthony (1599-1641)Artist120135.43155
Vauban, Sebastian de (1633-1707)Soldier100125.43140
Vega, Lope de (1562-1635)Poet, novelist140145.43175
Velasquez, Diego (1599-1660)Artist125140.20170
Vergniaud, Pierre (1753-1793)Revolutionary130135.20170
Vinci, Leonardo da (1452-1519)Artist135150.20180
Voltaire, Arouet de (1694-1778)Poet, novelist170180.75190
Wagner, Richard (1813-1883)Musician135150.53170
Wallenstein, Albrecht von (1583-1634)Soldier110115.11135
Walpole, Robert (1676-1745)Statesman125130.43155
Warburton, William (1698-1779)Religious leader115130.43155
Washington, George (1732-1799)Soldier125135.75140
Watt, James (1736-1819)Scientist140145.60165
Weber, Karl Maria von (1786-1826)Musician135145.53165
Webster, Daniel (1782-1852)Statesman145150.60165
Wesley, John (1703-1791)Religious leader135140.60160
Wieland, Christopher M. (1733-1813)Poet, novelist160160.75170
Wilberforce, William (1759-1833)Statesman120130.43155
Wilkes, John (1727-1797)Statesman120125.43150
Winckelmann, J. J. (1717-1768)Essayist, scholar145145.60165
Wolf, Friedrich August (1759-1824)Essayist, scholar155165.75175
Wolsey, Thomas (1475-1530)Statesman165165.11200
Wordsworth, William (1770-1850)Poet, novelist150155.75165
Zwingli, Ulrich (1484-1531)Religious leader140140.43165

Source: Cox (1926), Tables 12A and 12B [2]. Names as Cox printed them. Childhood = to age 17 (AI), youth = 17 to 26 (AII); records = Cox’s reliability rating of the youth data (0 to 1); corrected = her corrected youth figure; (B) = her smaller Group B. The CSV adds the corrected childhood figure and every other column.

12 What the estimates cannot tell you

Read every number with these in mind

  • No one in the study took an IQ test. Each number is three psychologists’ judgment of written records, mostly biographies.
  • The raters knew who each person became, and the records were written by admirers. Both can lift estimates.
  • Thin records give lower estimates (Figure 3), so the table partly measures how well a childhood was documented.
  • The scores are 1920s ratio IQs, which are not on the same scale as modern deviation IQs, especially at the top.
  • The corrected figures are, in Cox’s words, a crude approximation and a floor, not a person’s score [1].
  • The group is drawn from a 1903 ranking of eminence. It is mostly European and American, mostly men, and leaves out everyone born after 1850.
  • Our checks found one printed corrected value (Schelling, childhood: 180) that does not match Cox’s own formula, which gives 185. We publish what she printed.

Cox’s data are still used: Dean Keith Simonton and Anna Song re-analysed her main group in Psychological Science in 2009 [5]. For the companion study of real tested children, see Terman’s gifted children; for record test scores today, the highest IQ ever recorded.

Your own score, measured

Cox could only estimate from records. Our IQ test measures your reasoning today and places it against adults, with a percentile and a confidence range.

Take the IQ test

13 How was this study built?

  1. 01

    Find the tables

    Cox’s per-person figures are in fold-out Tables 12A (Group A) and 12B (Group B), facing p. 60. They are unreadable in the common archive.org scan, so we read them from a second scan that holds the fold-outs as wide page images [2].

  2. 02

    Type every row

    For each of the 312 rows we typed the name, dates, nationality, field, both estimates with their probable error, reliability grade and coefficient, the two corrected figures and the trait-rating reliability: 22 values a row.

  3. 03

    Check against Cox's own totals

    A script compared our rows with everything Cox printed elsewhere: the number of people at each IQ level (Tables 6 and 7) matched exactly; group means matched her Tables 7, 20A and 20B; ranks ran 1 to 282 once each; every corrected value was recomputed from her formula (p. 82); each probable error matched its reliability grade.

  4. 04

    Re-read what did not fit

    Rows that failed a check, and the most quoted names, were re-read on the page image. One printed value differs from Cox’s formula (Schelling); we kept the printed value and say so.

  5. 05

    Compute and publish

    Counts, averages, quartiles and the correlation on this page are ours, computed from the typed table. All of it is in one CSV under CC BY 4.0. Our standards are on the methods page.

Sources

  1. Stanford University Press. Cox, C. M. Genetic Studies of Genius, Vol. II: The Early Mental Traits of Three Hundred Geniuses. 1926. archive.org/details/geneticstudiesof011555mbpPublic domain (US)
  2. Internet Archive. Cox, C. M. (1926), Tables 12A and 12B (fold-outs facing p. 60), read from a second scan of Vol. II. 1926. archive.org/details/geneticstudiesof0002cath_c2h2Public domain (US)
  3. Popular Science Monthly. Cattell, J. McK. A statistical study of eminent men. Popular Science Monthly, 62, 359-377. 1903. en.wikisource.org/wiki/Popular_Science_Monthly/Volume_62/February_1903/A_Statistical_Study_of_Eminent_MenPublic domain
  4. University of Illinois Press. Terman, L. M. The intelligence quotient of Francis Galton in childhood. American Journal of Psychology, 28(2), 209-215. doi:10.2307/1413721. 1917. doi.org/10.2307/1413721Public domain (US)
  5. SAGE. Simonton, D. K., & Song, A. V. Eminence, IQ, physical and mental health, and achievement domain. Psychological Science, 20(4), 429-434. doi:10.1111/j.1467-9280.2009.02313.x. 2009. doi.org/10.1111/j.1467-9280.2009.02313.xFacts cited

Version history

  • 2026.1026 October 2026First release.
Leon Falkner

Leon Falkner, Data & Research Analyst. Leon owns the arithmetic on IQ Metrics: the percentile tables, the score converter and the figures in everyone else's drafts. On the research desk Leon pulls the data, builds each index and writes the method. More about Leon.

Questions

What was Isaac Newton's IQ according to Cox?

Cox's raters estimated 130 for childhood and 170 for ages 17 to 26. The 190 often quoted is her corrected youth figure, which she called a floor rather than an exact value.

Who had the highest IQ in Cox's study?

Goethe: the raters estimated 185 for childhood and 200 for youth, and his corrected youth figure is 210. John Stuart Mill had the highest childhood estimate, 190.

Did these geniuses take IQ tests?

No. All of them were dead long before IQ tests existed. Three psychologists estimated each IQ from written records of the person's childhood and youth.

Is Einstein in Cox's study?

No. Cox covered people born between 1450 and 1850; Einstein was born in 1879. IQ figures quoted for Einstein do not come from her tables.

What is a corrected IQ in Cox's study?

A second figure Cox printed for each person, pushing the estimate toward the average of the person's field when the records were thin. It adds about 20 points on average. She called it a crude approximation of a floor, not a score.

Why does Shakespeare have no IQ estimate?

Cox listed him but found too little recorded about his early years to rate him. Ten others, including Machiavelli and Titian, have no estimate for the same reason.

Use the data

Share it, cite it, download it

You may reuse everything on this page under CC BY 4.0: in articles, reports, lessons and posts. The one condition is credit to IQ Metrics with a link to this page.

Cite this study

Version 2026.10. Citing the version lets readers find the exact numbers.

Archived copy with a DOI: 10.5281/zenodo.23664396 (report PDF and data on Zenodo).

Falkner, L. (2026). The IQs of 301 geniuses: Cox's 1926 estimates, in full (Version 2026.10) [Data set]. IQ Metrics Research. https://iqmetrics.org/research/iq-of-historical-geniuses/ (DOI: 10.5281/zenodo.23664396)

Get the data

All 312 rows of Catharine Cox’s Tables 12A and 12B (1926): both IQ estimates per person with probable errors, reliability grades and coefficients, corrected estimates, trait-rating reliability, eminence rank, dates, nationality and field, as printed.

Download CSV
Data dictionary
ColumnWhat it holds
group, rankCox's Group A (main, 282 rated + 11 unrated) or B (19); rank of eminence within the group (A: 1 = Napoleon; ties printed as x.5)
name_printed, nameThe name as Cox printed it, and the name as most readers would search it
dates, born, died, nationality, fieldAs printed (field codes: Writer PND = poets, novelists, dramatists; Writer EHCS = essayists, historians, critics, scholars)
ai, ai_pe, ai_grade, ai_reliabilityChildhood estimate (to age 17): IQ, probable error, reliability grade (1 to 7) and reliability coefficient
aii, aii_pe, aii_grade, aii_reliabilityThe same for youth (ages 17 to 26)
corrected_ai, corrected_aiiCox's corrected estimates (Formula a, p. 82)
trait_reliability, group_cReliability of Cox's character-trait ratings, and whether the person is in her Group C of 100 used for them
rated, noteyes / no, and Cox's note for the 11 without estimates
table, sheet_rowTable 12A or 12B, and the row position on our page images of the fold-out

Share this finding

A finished image and a ready message. The image carries the source line, so the credit travels with it.

Each network gets a version sized for it unless you edit the message.

Press kit

For journalists, researchers and teachers

Everything on this page may be quoted, charted and republished with credit. No embargo, no permission needed, no sign-up. If you need a number that is not here, ask.

Summary you can paste

Plain news style. Edit freely; keep the credit.

In 1926 Stanford psychologist Catharine Cox estimated the IQs of 301 historical geniuses born 1450-1850 from records of their early lives (Genetic Studies of Genius, Vol. II). An IQ Metrics Research transcription of her full tables, checked against her printed totals, shows the raters averaged 135 for childhood and 145 for youth. Only 9 people were put at 180 or more; after Cox's "correction", 57 were, and the correction added 20.1 points on average. Famous figures such as Newton's 190 and Leonardo's 180 are corrected values. Estimates rose with the quality of the records (121 for the thinnest, 168 for the richest). Shakespeare got no estimate. Source: IQ Metrics Research, https://iqmetrics.org/research/iq-of-historical-geniuses/

Angles for a story

  • Where “Leonardo’s IQ was 180” comes from, and why it is a corrected figure (the correction).
  • Better-documented childhoods got higher scores (Figure 3).
  • Philosophers top, soldiers bottom (Figure 4).
  • Shakespeare has no score, and Einstein is not in it (who is missing).
  • A 100-year-old study: the book appeared in 1926 (the study).
  • Look up anyone and download a share card (look-up).

Quotes you can use

Attributable as written, with the name and title. For a different angle or a quote on a specific figure, ask through the contact page.

  • Most of the famous IQs of 180 and above in history are not what Cox’s raters estimated. They come from a correction she herself called a crude approximation.

    Leon Falkner, Data & Research Analyst, IQ Metrics Research

  • The strongest predictor of a high estimate in Cox’s study is how much was written about a person’s childhood. Every number is a judgment from records, not a test.

    Leon Falkner, Data & Research Analyst, IQ Metrics Research

  • Shakespeare has no score at all. Cox’s team found too little about his early years to rate him, and Einstein was born too late to be in the study.

    Leon Falkner, Data & Research Analyst, IQ Metrics Research

Files

  • CSV of all 312 rows, every column of Cox’s Tables 12A and 12B (CC BY 4.0)
  • Every figure as a print-ready PNG: use the Image button under each figure
  • Share images for social media in three sizes, with the credit line built in
  • Citations in APA, MLA, Chicago, BibTeX and plain text

Terms, contact and corrections

Credit: “IQ Metrics Research, Cox’s 301 Geniuses” with a link to this page. On air or in print, “IQ Metrics” and the page address are enough.

Data credit: estimates from Cox (1926) [1]; the transcription, checks, counts and charts are ours.

Please say “estimated IQ” and which estimate you quote (childhood, youth or corrected); none of these people took a test.

Contact: the research team, through the contact page. Corrections are made on this page with a dated note in the version history.

Keep reading

Related research

Data studyTerman's Termites: what happened to 1,528 gifted children
Data studyWhich universities produce the most prize-winning scientists?
Data studyMensa by the numbers
Technical reportHow IQ Metrics Research works: methods and standards