[scott_s]

I think what we call "morality" probably has a biological basis as well. Humans are social animals. Hence, we're going to have selection pressures towards behaviors (and the internal thinking required to produce those behaviors) that preserve social groups. If we didn't, human groups wouldn't survive, and we wouldn't be social animals. I think we can point to other social animals as examples. There's also support in the fact that there are broad similarities across cultures about what is moral - for example, murder is wrong. If there was no biological basis, I think we'd see far more variation in what we call "morals."