The chimpanzees could tear me apart in no time. They're many times stronger than we are.

We would much rather blame nature for what we don't like in ourselves than credit it for what we do like.

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

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.

To endow animals with human emotions has long been a scientific taboo. But if we do not, we risk missing something fundamental, about both animals and us.

After World War II it was decided that, in order to prevent the Germans and the French from having another war, it would be better to tie them together into one economic pact so they would invest in each other and have mutual stakes. Until now, that has worked to prevent warfare between the two.

Empathy probably started out as a mechanism to improve maternal care. Mammalian mothers who were attentive to their young's needs were more likely to rear successful offspring.