The Daily Dot: Why dudes don’t greet dudes

Researchers have noted before that men’s friendships with other men—especially straight, white men’s friendships with other men—tend to lack the sort of intimacy and openness that we generally associate with close friendships. Moreover, contrary to popular belief, men want these things from their friendships as much as women do.
Perhaps as a result, men as well as women tend to confide more in women than in other men.

via Why dudes don't greet dudes.