I think it has more to do with how each gender defines "video games". Most women I see play Solitiare, Bejeweled, tetris, and other puzzel type games. Most men and boys I see play Quake, Unreal, Half-Life, Mechwarrior, Age of Kings, etc.
Basically, male play the more competative battle type winner takes all single or team play games. Women seem to play more noncompetative type games where they acompish a goal of some type.
Not that this is strictly how it is, just from my observations.
