In this article, I discuss Terence Tao’s scores on the old (much more difficult) SAT.
Verbal score
According to this source , at age 8.8, Terence Tao scored 290 on the verbal section of the pre-1995 SAT(hat-tip to commenter Tenn for finding this data since my google searches for Tao’s verbal SATs turned up nothing) .
If all American 17-year-olds took the old SAT in the 1980s (not just the college-bound elite) the mean verbal score would have been 375.8 and the standard deviation (SD) would be 102.
Thus Tao scored 0.84 standard deviations below the average American-17-year-olds. But given that he was only 8.83, he deserves a huge age bonus.
On the WISC-R Vocabulary subtest (the subtest most similar to the verbal SAT), an 8.8-year-old who scores about 0.84 SD below American 16.8-year-olds (16 to 25 percentile), is actually about 2.17 SD above the mean for his own age (98-99 percentile), implying a verbal IQ of 133 (U.S. norms) or 132 (white norms).
Math score
The New York Times magazine reports:
By the spring of 1985, with a 9-year-old Tao splitting time between high school and nearby Flinders University, Billy and Grace took him on a three-week American tour to seek advice from top mathematicians and education experts. On the Baltimore campus of Johns Hopkins, they met with Julian Stanley, a Georgia-born psychologist who founded the Center for Talented Youth there. Tao was one of the most talented math students Stanley ever tested — at 8 years old, Tao scored a 760 on the math portion of the SAT — but Stanley urged the couple to keep taking things slow and give their son’s emotional and social skills time to develop.
If all American 17-year-olds took the old SAT in the 1980s (not just the college-bound elite) the mean math score would have been 411.5 and the standard deviation (SD) would have been 109.
Thus Tao at about age 8.8, scored 3.2 standard deviations above the average U.S. 17-year-old.
I don’t know where this would put him compared to U.S. 8.8 year-olds on the math SAT, but on the WISC-R IQ test, U.S. 8.8 year-olds who score in the top 15% of U.S. 16.67-16.997-year-olds on Arithmetic (the subtest most similar to the math SAT) make the top 0.01% among their own age group. This suggests an age bonus of about two standard deviations.
Thus Tao, was likely 5.2 standard deviations above the U.S. mean for his age, suggesting a math IQ of 178 (U.S. norms) and also 179 (white norms).
Composite score
Assuming about a 0.67 correlation between verbal and math, the composite IQ of someone with Tao’s cognitive profile is about 161 (U.S. norms); 161 (white norms).
It’s possible I’m underestimating Tao’s IQ because his childhood Raven IQ is arguably even higher than his math IQ and people of East Asian descent often do best at spatial ability which both the SAT and Raven downplay. On the other hand, I could be overestimating his IQ because some math geniuses lack social intelligence and common sense, which is also not especially well measured by the SAT.
Both of these objections likely cancel each other out, leaving 161 as a good proxy for his overall cognition.