I would have to say the majority of my friends are girls (about 70%). I have some really close friends that are guys, but overall my friends are female. I typically hang out with the girls more often as well. Despite this, my best friend is male. I don't think that the reason I am friends with more girls is because they're the opposite gender. I'm not attracted to most of my girl friends. It's probably more of chance than anything else, but there could be some real mathematical and psychological ties to this. Great question!