Via Brute Reason (two weeks ago >.>), Miri highlights a study that demonstrates a correlation between men’s enjoyment of sexist humor and a tendency toward sexist behaviors and actions. This includes acceptance of rape culture, likelihood to show aggressive behaviors, and even willingness to rape. The study also looked at how much women enjoy sexist humor, and found that it also correlated with sexist beliefs, although it did not correlate with aggressive tendencies.
Honestly, this isn’t that surprising. I’ve often seen people try to defend their sexist statements behind a cover of humor. For instance, Daniel Tosh received quite a bit of criticism for his “rape joke”, which was really just telling a woman in the audience that she should be raped. More recently, Mark Driscoll has been getting some flack over his comments which were both really sexist and anti-environmental. They seem to think that just because they said their sexist comments humorously, that somehow makes them less sexist. Of course, the research says otherwise.
If you want a more thorough explanation of the study, you should read Miri’s post about it here.