A chimpanzee who is really gearing up for a fight doesn't waste time with gestures but just goes ahead and attacks.

It is hard to get animals which normally pay little attention to each other to do things together. One can teach dolphins to jump simultaneously out of the water precisely because they show similar behavior spontaneously, but try to make two domestic cats jump together and you will fail.

When it comes to social interaction, the chimpanzees appear to be just as intelligent as we are.

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

Why not assume that our humanity, including the self-control needed for livable societies, is built into us? Does anyone truly believe that our ancestors lacked social norms before they had religion? Did they never assist others in need, or complain about an unfair deal? Humans must have worried about the functioning of their communities well before the current religions arose, which is only a few thousand years ago.

Most exotic animals are not particularly interested in people, which makes it hard to provoke them. Human-rearing gets them used to and sometimes imprinted on humans, which makes them potentially dangerous.

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.