When I began in 1960, individuality wasn't an accepted thing to look for; it was about species-specific behaviour. But animal behaviour is not hard science. There's room for intuition.

We, as humans, have actually developed a sense of social responsibility. We have gone beyond our basic instincts.

Louis [Leakey] was anxious to initiate a scientific study of these chimpanzees. It would be difficult, he emphasized, for nothing was known; there were no guidelines for such a field study; and the habitat was remote and rugged. Dangerous wild animals would be living there, and chimpanzees themselves were considered at least four times stronger than humans. I remember wondering what kind of scientist he would find for such a herculean task.

I think the most important thing to do is to be willing to listen, willing to care, and willing to admit mistakes and change your ways for the better!

If only we can overcome cruelty, to human and animal, with love and compassion we shall stand at the threshold of a new era in human moral and spiritual evolution - and realize, at last, our most unique quality: humanity.

We have a responsibility toward the other life-forms of our planet whose continued existence is threatened by the thoughtless behavior of our own human species. . . . Environmental responsibility – for if there is no God, then, obviously, it is up to us to put things right.

If we start with chimpanzees, they differ from us with the composition of the DNA by only just over one percent. So, as far as genetics go, we're almost identical. The composition of the blood, the immune system, the structure of the brain - almost identical.