I've got different ideas of complete happiness. But one is being by myself out in a forest, completely happy. Another is walking with a dog in some nice place. And three is sitting around preferably a fire, but not necessarily, and drinking red wine with friends and telling stories.

It's been proven by quite a few studies that plants are good for our psychological development. If you green an area, the rate of crime goes down. Torture victims begin to recover when they spend time outside in a garden with flowers. So we need them, in some deep psychological sense, which I don't suppose anybody really understands yet.

And I thought how sad it was that, for all our sophisticated intellect, for all our noble aspirations, our aggressive behavior was not just similar in many ways to that of the chimpanzees - it was even worse. Worse because human beings have the potential to rise above their baser instincts, whereas chimpanzees probably do not.

I've got different ideas of complete happiness. But one is being by myself out in a forest, completely happy. Another is walking with a dog in some nice place. And three is sitting around preferably a fire, but not necessarily, and drinking red wine with friends and telling stories.

Chimpanzees, more than any other living creature, have helped us to understand that there is no sharp line between humans and the rest of the animal kingdom. It's a very blurry line, and it's getting more blurry all the time.

I thought my life was mapped out. Research, living in the forest, teaching and writing. But in '86 I went to a conference and realised the chimpanzees were disappearing. I had worldwide recognition and a gift of communication. I had to use them.

I sometimes wonder how some people can live with themselves in some of the big companies today. So many far-reaching decisions are based on how they will affect the next shareholders' meeting.