Founding Fathers Ranked by IQ: What Cox's 1926 Estimates Show

Who was the smartest Founding Father? On the only IQ-style estimates that exist, Thomas Jefferson and Benjamin Franklin lead the six Founding Fathers whom the psychologist Catharine Cox rated in 1926, and George Washington is last. None of the six took an IQ test; each number is an estimate built from what biographers recorded about their childhood and youth. This article gives the full ranking, explains what the four numbers per man mean, shows why Washington comes last and why Adams and Madison are a special case, and links the result to our US presidents ranked by IQ table, which covers only the four who became president.

Founding Fathers ranked by IQ: Cox's estimates for all six

Cox gave each man two estimates from the record, one for childhood to age 17 and one for the evidence to age 26, and then corrected each for how complete the record was. That gives four numbers per man. The ranking below uses the average of the four, the same way our presidents article does for the presidents. Each line gives the average, then the two uncorrected estimates and the two corrected ones:

• 1. Thomas Jefferson: 153.8 (145 and 150; corrected 160 and 160), third president
• 2. Benjamin Franklin: 152.5 (145 and 145; corrected 160 and 160), never president
• 3. Alexander Hamilton: 145.0 (135 and 140; corrected 150 and 155), never president
• 4. John Adams: 142.5 (120 and 145; corrected 150 and 155), second president
• 5. James Madison: 141.3 (120 and 135; corrected 150 and 160), fourth president
• 6. George Washington: 132.5 (125 and 135; corrected 130 and 140), first president

The six average 144.6 on this method. Treat the order as soft. On the corrected later estimate alone, Jefferson, Franklin and Madison tie at 160, Hamilton and Adams share 155, and only Washington stands apart at 140. What holds under every way of counting is that Jefferson and Franklin sit at the top and Washington at the bottom. The numbers are on Cox's old mental-age scale, so they are not directly comparable with a modern score, as our explainer on deviation IQ and the old ratio formula explains.

Was Alexander Hamilton the smartest Founding Father?

Not on these numbers, though he is third of six. Cox rated Hamilton 135 and 140 from the record and corrected them to 150 and 155. The 155 that circulates online is the second of the corrected pair, not a test result, as our Alexander Hamilton IQ profile sets out. His record is strong early, with Cox noting that he was a counting-house clerk at 12 and that people who read his description of a storm at 15 decided to pay for his college education, but a single set of estimates cannot separate him from Adams, who scores identically on the corrected pair. If you are asking who was most admired, Cox's own order of fame points elsewhere, as the next section shows.

What do Cox's four numbers actually measure?

Catharine Cox, working at Stanford with Lewis Terman, studied 301 people born between 1450 and 1850 and published the work as The Early Mental Traits of Three Hundred Geniuses. Three raters, Terman, Maud Merrill and Cox, read each person's record and estimated the IQ the person would have shown on the Stanford-Binet test. The first estimate (AI) uses the evidence to the 17th birthday and the second (AII) the evidence to the 26th. Our IQ of historical geniuses study sets out all 301.

Both estimates are then corrected. Cox's formula adds to each score the group's distance above 100 multiplied by one minus the reliability of the record, so thin records are pulled towards the professional group's average. She was open about the limits. Her correction, she wrote, is "a crude approximation" that indicates a point below which the true IQ probably did not fall, and elsewhere "no more than an approximation to a true score". That is why a corrected 160 is best read as a floor on a guess, not a measurement.

Why is George Washington last?

Because of a filing decision as well as the evidence. Cox put each person in one professional group by the field of their main eminence, and she grouped Washington with the soldiers, not the statesmen. Her printed group means for the uncorrected estimates are 115 and 125 for soldiers and 135 and 142 for statesmen. Because the correction pulls a score toward its group's mean, Washington gains only 5 points on each estimate (125 to 130, 135 to 140), where Franklin gains 15 (145 to 160 on both).

Run the same record through the statesmen's means and the formula gives roughly 139 and 145 before rounding, instead of 130 and 140. That is our recalculation from Cox's printed formula, not a figure she published, and it would still leave him last of the six, because the next lowest, Adams, scores 150 and 155. So the soldier classification costs Washington about 9 points but does not change his place. For the man himself, George Washington's IQ profile covers the 130 and 140.

Why are Adams and Madison rated 120 first?

Because almost nothing survived about their childhoods. Cox gave John Adams and James Madison an uncorrected first estimate of 120, but the reliability of that record is only .20, the lowest in the group: her case summaries mark most childhood headings as having no record. The formula then adds 28 points, to 148, which she rounds to 150. Their corrected first scores of 150 are therefore mostly the formula, not evidence. By the evidence to age 26 the picture is firmer, with an uncorrected 145 for Adams, a Harvard graduate admitted to the bar at 23, and 135 for Madison, who finished Princeton in two years.

Cox kept the list in the order of J. McKeen Cattell's 1903 ranking of eminence. In that order Washington is 10th of her 282 main subjects, Franklin 25th, Jefferson 49th, Adams 104th, Hamilton 118th and Madison 270th. Fame and the estimates do not track each other, which is one reason the numbers should not be read as a ranking of greatness.

How do the Founding Fathers compare with Cox's other 295?

Less impressively than the popular lists suggest. Of the 301 people Cox rated, 172 have a higher corrected later estimate than the 160 shared by Jefferson and Franklin, and 282 have a higher one than Washington's 140. Cox's own printed averages for statesmen are 155 and 165 on the corrected pair, so Franklin and Jefferson sit about 5 points below their professional group. The highest-rated American in the whole study is not a Founding Father but John Quincy Adams, at 170 and 175; see our John Quincy Adams IQ profile. For the wider group of leaders she rated, see world leaders ranked by IQ.

How do these numbers connect to the US presidents ranking?

Four of the six became president, and Dean Keith Simonton's 2006 study used Cox's ratings as the anchor for the first eight presidents. The averages above are the four-value averages that our presidents article prints: Jefferson 153.8 (second of 42), John Adams 142.5 (seventh), Madison 141.3 (eleventh) and Washington 132.5 (twentieth). Franklin and Hamilton were not presidents, so they are not in Simonton's table; on the same arithmetic Franklin's 152.5 would sit between Jefferson and John F. Kennedy's 150.7. For the whole picture, including the hoax list that gives Clinton 182, read US presidents ranked by IQ; for the British equivalent, where no study exists, UK prime ministers ranked by IQ.

What did their early records show?

Cox's case summaries are the evidence behind the numbers, but they contain slips, such as saying Adams entered Harvard at 16 (he was 15) and that Hamilton qualified for a degree (he never completed one), so we give the institutional record alongside:

• Washington: no college; Cox notes "a fair common school education" and a start as a professional surveyor at 15
• Franklin: sent to grammar school at eight and taken home at ten, in his own words; Cox says he rose from the middle of his class to the head within a year
• Jefferson: by 15 he had read all the books in his father's small library, according to Cox, and he attended William and Mary from 1760 to 1762
• John Adams: entered Harvard in 1751 and received his A.B. in 1755
• Madison: entered Princeton as a sophomore in 1769 and took his degree in the fall of 1771
• Hamilton: entered King's College in 1773 but the Revolution interrupted his studies and he never completed the course

Who else counts as a Founding Father, and why are they missing?

There is no official list. The National Archives uses the term for the delegates to the Constitutional Convention, 55 of whom attended and 39 of whom signed, while the historian Richard B. Morris picked seven in 1973: Adams, Franklin, Hamilton, John Jay, Jefferson, Madison and Washington. Cox covers six of Morris's seven; John Jay is not one of her subjects. Neither are Thomas Paine, Patrick Henry, Gouverneur Morris, George Mason, Benjamin Rush, Samuel Adams, John Marshall, Aaron Burr, James Monroe or John Hancock. For all of them, no estimate exists, and any figure you see for them is invented. For the philosophers and scientists Cox rated, see our philosophers ranked by IQ.

So the honest ranking of the Founding Fathers by IQ is a short one, with a wide margin: Jefferson and Franklin first, Hamilton, Adams and Madison close behind, and Washington last, all on a 1926 estimate from biographies. To see where any such score sits on the curve, use the percentile calculator and the IQ bell curve, and read where celebrity IQ numbers come from before you trust the next list. Our profiles of Benjamin Franklin and Thomas Jefferson give the record person by person.

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