RADFORD: You've just raised a huge question, which could keep us happy all night, I'll try to get our two guests to answer it. Why do things go wrong? The question is a serious one. If evolution is for the best, if a religious sense provides us with the stability to go through life, why do things go wrong? There's a whole Robert Bresson film devoted to this one, it's called The Devil Probably; there's a Kurt Vonnegut statement as well. Who wants to take this one on?

DAWKINS: That's not what I gathered the question was. Nobody's ever said evolution is for the best, except insofar as it's for the best of the genes, and that's another matter. I don't think there was a question there at all; I think that was a statement, which we should be grateful for.

PINKER: I think that evolution and genetics and neuroscience are essential parts of an explanation of human behavior, but that doesn't mean that people are sealed in a barrel, oblivious to the standards of behavior set by other people, and unable to make decisions based on them. Quite the contrary -- one of the things our brains are designed to do is learn the contingencies of the social world we find ourselves in. Obviously there is variation among cultures, which is made possible by the fact that people innovate and people learn other people's innovations. Also, the optimal way to behave in a given situation depends on how other people behave and react to one's own behavior, and those contingencies vary from place to place and have to be learned. There are large differences, orders of magnitude, in rates of violent encounters across different countries, although the psychology of the violent encounters is strikingly similar. The rates differ because of differences in the cultures and social values, those values aren't like a gas that seeps out of the earth and that people merely breathe in. They emerge from a bunch of minds interacting in a group, exchanging ideas, assessing one another, making decisions. So culture itself, even though it's part of any explanation of behavior, itself has to be tied to the psychological and ultimately neurological mechanisms that allow cultures to arise to begin with.