It's not magic: Given a large, random sample of self-identified 'men' and 'women', pitting them against each other in one-to-one unarmed combat, the men will win an overwhelming majority of the time.

I enjoy working with women who are trained in self-defense - I have a female friend who has a devastatingly strong and quick round kick to the jaw. However, as with most people, most women aren't.

This is a great organization mobilizing around this topic (although their website is sorta crap): http://www.2asisters.org/