Animal Behavior

I took my kids to the zoo yesterday. We're members, and it's not that far away, so we really should go more often. Especially since they're doing so much to improve the environments in which the animals live. It's a completely different place than it was when I was a kid, or even a teenager driving the little train around the duck pond.

I was struck by how many behaviors animals and people have in common. And not just with the chimps and other monkeys! We all have a desire to be clean (actually, some of the animals seem far more fastidious in that regard than people), we all eat regularly, we all seek out the company of our own kind. But with animals it's less complicated, it appears. Human animals manage to mess it up somehow, hurt each other often without meaning to.

Why?