What makes us human, I think, is an ability to ask questions, a consequence of our sophisticated spoken language.

But does that mean that war and violence are inevitable? I would argue not because we have also evolved this amazingly sophisticated intellect, and we are capable of controlling our innate behavior a lot of the time.

In Tanzania, the chimps are isolated in a very tiny patch of forest. I flew over it 13 years ago and realized that, basically, all the trees had gone, that people all around the park are struggling to survive. It became very clear that there was no way to protect the chimps while the people were in this dire circumstance.

Some humans are mathematicians-others aren't.

The only possible way to get somebody to change is to reach into their hearts.

Other people have talked about chimpanzees being a window into the past, which I suppose is true, in a way.

Chimpanzees have given me so much. The long hours spent with them in the forest have enriched my life beyond measure. What I have learned from them has shaped my understanding of human behavior, of our place in nature.