But what you're saying is that if you're already a sexist pig, then jokes about women encourage you. Duh. but it misses the fact that you're talking about someone who's already a sexist. It's like saying republicans won't vote for obama. It's a done deal.

but since jokes make sexists sound more sexist (though I doubt they make them more sexist) and since they don't make me and other non-sexist people more sexist, my best guess is that they have almost no effect on actual sexism.

My suggestion is to pay more attention to what people are actualy taught about women and less about jokes. I'd be interested in learning when it is that children are taught sexism. Maybe by posturing dick fathers. I was raised almost entirely by my mother who was a single mom and sort of a bitch. I never even learned that women COULD be weak, let alone that they were supposed to be.