I don’t know a source for the number, but in one of his popular books he mentioned that Mensa contacted him and he responded that his IQ wasn’t high enough, which means it was less than 130.
I suspect that this test emphasized verbal, as opposed to mathematical,
ability. Feynman received the highest score in the country by a large margin
on the notoriously difficult Putnam mathematics competition exam, although he
joined the MIT team on short notice and did not prepare for the test. [...]
It seems quite possible to me that Feynman’s cognitive abilities might have
been a bit lopsided—his vocabulary and verbal ability were well above
average, but perhaps not as great as his mathematical abilities. I recall
looking at excerpts from a notebook Feynman kept as an undergraduate. While
the notes covered very advanced topics—including general relativity and
the Dirac equation—they also contained a number of misspellings and
grammatical errors. I doubt Feynman cared very much about such things.
I don’t know a source for the number, but in one of his popular books he mentioned that Mensa contacted him and he responded that his IQ wasn’t high enough, which means it was less than 130.
Knowing Feynman, This might well have been a joke at their expense.
According to Feynman, he tested at 125 when he was a schoolboy. (Search for “IQ” in the Gleick biography.)
Gwern says:
Steve Hsu says:
It is a joke at their expense. The question is whether he based it on a true premise.