The development of family entities enables men to cooperate far more effectively. Instead of constantly competing for the women with other men, each man essentially has a partner assigned to him, one with whom he can establish a family.

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.

As far as the environment is concerned, I am becoming pessimistic because I do not see anybody stepping up and taking the long view approach. It seems like we're stuck in a tragedy of the commons where everyone is trying to contribute as little as possible to get out of this situation.

It wasn't God who introduced us to morality; rather, it was the other way around. God was put into place to help us live the way we felt we ought to.

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

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.

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?