Seconding SoullessAutomaton's reply. Also making an analogy to discussions of race.

In addition: "overwhelming hard data" isn't too high a standard when prejudice and other cultural factors cloud the picture. I don't think it's too big a stretch to suppose that such factors are present in this case.

(Finally: a stronger emphasis on hard data in the meta-gender discussion might not be a bad thing, but remaining silent when a problem of this kind exists is a decidedly bad thing.)