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.

Humans have a lot of pro-social tendencies.

We are territorial, power-hungry and even more brutal than chimpanzees.

Humans became easy prey when they moved from the forest to the savanna, which deprived them of the option of climbing trees to flee predators. This shift made it necessary for the men to actively protect the women and their babies. Only as a result of this protection were women able to give birth in shorter intervals, perhaps once every two or three years. This meant that they could produce offspring about twice as frequently as apes. I would be willing to bet that this rapid reproduction is one of the reasons why we dominate the world today, and not the apes.

Personally, I think it is possible to build a society that is moral on a nonreligious basis, but the jury is still out on that.

Bonobo studies started in the '70s and came to fruition in the '80s. Then in the '90s, all of a sudden, boom, they ended because of the warfare in the Congo. It was really bad for the bonobo and ironic that people with their warfare were preventing us from studying the hippies of the primate world.

It is well known that apes in the wild offer spontaneous assistance to each other, defending against leopards, say, or consoling distressed companions with tender embraces.