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.
I intended Leveling Up in Rationality to communicate this:
But some people seem to have read it and heard this instead:
This failure (on my part) fits into a larger pattern of the Singularity Institute seeming too arrogant and (perhaps) being too arrogant. As one friend recently told me:
So, I have a few questions: