If you are a cooperative animal you need to watch what you get. If you, or even a whole community, invest in something but then a few individuals receive a much larger return, it's not a good arrangement. If it happens consistently, it's time to look for an arrangement that is more beneficial. That's why we're so sensitive to how rewards are being divided.

The role of inequity in society is grossly underestimated. Inequity is not good for your health, basically.

There's actually a lot of evidence in primates and other animals that they return favors.

I've argued that many of what philosophers call moral sentiments can be seen in other species. In chimpanzees and other animals, you see examples of sympathy, empathy, reciprocity, a willingness to follow social rules. Dogs are a good example of a species that have and obey social rules; that's why we like them so much, even though they're large carnivores.

When we are bad, we are worse than any primate that I know. And when we are good, we are actually better and more altruistic than any primate that I know.

I think we need to start thinking about grounding our moral systems in our biology.

Science is not inherently good.