You could think of an ecosystem as a bunch of antagonistic arms races, almost: Everything that an animal depends upon for food is the body part of some other animal or plant who would just as soon keep that body part for itself.

There's a common criticism of evolutionary psychology that it's fatalistic and it dooms us to eternal strife, 'Why even try to work toward peace if we're just bloody killer apes and violence is in our genes?'

Paris Hilton, it turns out, is related to fellow celebrity jailbirds Zsa Zsa Gabor and G. Gordon Liddy.

The human capacity for compassion is not a reflex that is triggered automatically by the presence of another living thing.

The moral, then, is that familiar categories of behavior - marriage customs, food taboos, folk superstitions, and so on - certainly do vary across cultures and have to be learned, but the deeper mechanisms of mental computation that generate them may be universal and innate.

As women are empowered, violence can come down, for a number of reasons. By all measures, men are the more violent gender.

I don't think aggression works like thirst or sleep. I think aggression is more elicited by particular situations. I think it can be mitigated.