When I was a young child, my friends and I often played games on a boys vs. girls basis. This makes sense, young children don’t have sexual desires for the opposite sex, so it would follow that they’d group with their own gender, since the opposite gender is, well, different. But of course, with maturity all that went away, as boys and girls grow up and stop seeing each other on an out-group basis. But of course, not everyone grows up, most do, but not all. The ones who grew up are called adults, the boys who didn’t are called men’s rights activists, and the girls who didn’t are called feminists.