The ladies also seem to use more of the thread-starting icons (though 7 or 8 threads may not be a good sample size). Attention to detail? Appreciation for ornamentation? Newness of the forum? You be the judge.
I do stuff like this from time to time in order to generate threads for the Site Feedback forum, which I don't seriously address. (I'm testing against Yahoo!'s cache by changing the window title on the index page, mostly)