Well, height is correlated weakly with IQ (see cite above). Height is correlated with foot size so therefore IQ and foot size may be correlated as well. Whether foot size is an independent marker of IQ, I don’t know.
A high glial-cell-to-neuron ratio is correlated with intelligence, so if you allow for dissection or (:eek:) biopsy, you could probably gauge how intelligence your specimen is (or, was).
I recall reading the same; there’s a small correlation between intelligence and between being attractive, as well as being big and strong.
The hypothesis I recall being used to explain it was that being large, healthy, strong and symmetrical (a key part of beauty) implies both that the person is well fed and that they developed better than average physiologically. And the brain is produced by many of the same processes that produce the rest of the body, so on average if the body develops unusually well, so will the brain.