Likely mismeasured. He won the Putnam mathematics competition with a stunning margin without preparation. He reportedly had the highest scores ever on the math/physics graduate admission exams at Princeton. Both of these are reliable indicators of an IQ above 145, probably by a good bit. (And this is if you ignore the dozens/hundreds of theoretical physics professors who thought of him as the fastest thinker among them, and one of the deepest.)
Well, when we get obvious deviations between IQ and g (the thing IQ is stated in the academic literature as what it's trying to measure) some will say that the IQ test was administered incorrectly. Some will say that IQ tests aren't perfect.
IQ tests are probably both not perfect and administered incorrectly (often enough).
I think it's an almost meaningless number unless we're talking about very large groups of individuals, and there's a lot of evidence and theory to support that.
Likely mismeasured. He won the Putnam mathematics competition with a stunning margin without preparation. He reportedly had the highest scores ever on the math/physics graduate admission exams at Princeton. Both of these are reliable indicators of an IQ above 145, probably by a good bit. (And this is if you ignore the dozens/hundreds of theoretical physics professors who thought of him as the fastest thinker among them, and one of the deepest.)