It is not only visitors to the zoo who are fascinated but uneasy in the presence of chimpanzees; the same is true of scientists. The more they learn about these great apes, the deeper our identity crisis seems to become. The resemblance between humans and chimpanzees is not only external. If we look straight and deep into a chimpanzee’s eyes, an intelligent, self-assured personality looks back at us. If they are animals, what must we be?

The hamadryas baboon is a harem holder where one male mates with multiple females.

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

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.

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

We are by far the most contradictory of all primates. An animal with this much internal conflict has never lived on this earth.

If we look straight and deep into a chimpanzee's eyes, an intelligent self-assured personality looks back at us. If they are animals, what must we be?