'Tis the season...
What with the SuperBowl just having passed like a storm, I started thinking about why people are so zealous about sports. Like the comedian said (I'm paraphrasing and sanitizing), oppressed people riot about the condition of their lives, while civilized people riot when their sports team wins!
I think this is a perfect example of deep-seated primate behavior leaking through the facade of civilized society. When we were in tribes on the African plains, it was a Good Thing to support your tribe, and behaviors evolved to reinforce that activity. The guys that didn't care for the tribe were off in the woods, acting as appetizers for saber-toothed tigers.
Today, this tribal tendency leaks out in the more or less harmless outlet of team sports. We've decided that countries as tribes is a bad idea (it took several wars, and some still aren't convinced). So, now we have our teams where we can attach our savanna baggage.