For years this blog has has discussed Gates’s spectacular verbal and math IQ. But what about other parts of his intelligence?

Evidence of Gate’s social IQ can be gleaned from his performance at poker (a game involving bluffing and reading people). The late Paul Allen writes:

I spent more time with Bill at Currier House before his nightly Poker games with the local cardsharps. He was getting some costly lessons in bluffing; he’d win three hundred dollars one night and lose six hundred the next. As Bill dropped thousands that fall, he kept telling me, “I’m getting better”. I knew what he was thinking: I’m smarter than those guys.

From pages 71-72 of Idea Man by Paul Allen

Were the other players letting Gates win the first night so he would bet double the next night, or was he legitimately winning only half as often as he lost? Let’s assume the latter, in which case was likely a worse poker player than 2/3rds of the Harvard poker club.

On an abbreviated version of the WAIS-R, a sample of 86 Harvard students averaged IQ 128. Commenters Swank and pumpkinhead have argued this is an underestimate because the sample may not have been representative. On the other hand the WAIS-R norms were 25 years old, so the Flynn effect predicts IQ 128 would have been an overestimate. Error in both directions likely cancels each-other out, making 128 perhaps a plausible estimate.

Now if we assume Poker skill (like other measures of Theory of Mind) only correlates 0.43 with conventional measures of IQ, the Harvard poker club like averaged 28(0.43) + 100 = 112 in Poker IQ, and if Gates was worse than 2/3rds of them, his “Poker IQ” was likely only 107 (assuming similar practice, or assuming all had enough practice to reach diminishing returns).

So now we have two very rough estimates of Gates’s social IQ. “Fashion IQ” was 84 and “poker IQ” was 107. Both measures are of highly questionable validity, so unlikely correlate more than 0.5, thus a composite measure of his social IQ might be very crudely estimated at 95 which is extremely low compared to his his verbal and math IQ, but only slightly below the U.S. mean of 100.