It's an intriguing question that would probably get quite a response at any dinner party.
Frankly, I don't know. All I know is that the majority of vegetarians, ex-vegetarians, animal rights supporters, animal rescuers, animal shelter volunteers, and feral cat colony stewards that I know are women. Not all, but the majority. And I find that in conversations, women are more likely to listen and think about what I say than men, who often brush me off as an emotional female. That doesn't mean that I don't know thoughtful men who think about these issues, just that I've noticed the tendencies are definitely lopsided.