15,31,47
Men do not excel in all spatial tasks, though. Again contrary to popular myth, men and women are equally good at navigating. But this is another example of a task in which the sexes take different paths to the same destination. Women tend to rely on remembering landmarks, whereas men rely on their geometric skills to work out direction and distance.
Another proposal to explain the lack of women professors of maths and science is that even if there is little or no difference in average ability, there might be differences in the variation around this average, with more men found in the tails of the distribution curve and fewer in the middle. In other words, among males there are more idiots and more prodigies. One study of IQ, covering everyone born in Scotland in 1932, supports this idea. It showed that there were more women in the middle of the distribution, but more men at both of the extremes.