Helena Cronin makes an interesting point about the statistics of male and female ability. Whilst mean ability is approximately the same amongst men and women, the variance in male ability is considerably greater than the variance in female ability. As a consequence of this, the highest achievers tend to be male, and the lowest achievers tend to be male also.
Cronin points out that "discussions standardly zoom in on the means and blithely ignore the tails. So sex differences are judged to be small. And thus it seems that there's a gaping discrepancy: if women are as good on average as men, why are men overwhelmingly at the top? The answer must be systematic unfairness — bias and barriers. Therefore, so the argument runs, it is to bias and barriers that policy should be directed. And so the results of straightforward facts of statistical distribution get treated as political problems — as 'evidence' of bias and barriers that keep women back and sweep men to the top. (Though how this explains the men at the bottom is an unacknowledged mystery.)"