They're all actors, you see, and can never quite remember when they're offstage.  There's an audience available, so every one of them must have his or her say.

...I could guess they were playing the old game of squeeze-the-hand, trying to determine social status according to who could mash whose hand.  The whole ritual made me impatient; somehow I'd always thought that when men grew up, they left childish games behind.  But as I grew up myself, I saw that the petty competitions survived as rituals of competitive life.  I began to realize that those little struggles, like the enthusiasm for competitive sports, weren't really childish at all, but adult rituals to which children were introduced and guided early on.  The male of the species is built to battle other males - it goes back to the apes and way before them, for whatever reason.  We demonstrate our civilization by sublimating that drive into games, in which the risks are controlled and the likelihood of injury minimized.  The man who cheers at a football game is a living testament to evolution, and the dominance games that men live by all their lives are just part of the animal nature that still pervades all but two of our drives.  Boys are little men, not the other way around; it's just that they're more obvious, more open, and more honest about it than their elders are.