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 have so far to go to realize our human potential for compassion, altruism, and love.

I am obstinate and I will not give in.

Realize that change - whilst we want it to happen fast - is usually the result of a great deal of work, and often comes as a result of a series of compromises (so long as we do not compromise our values).

Even chimps understand the concept - if a troop of chimps enters a fruit tree, they will only pick the fruits that are ripe and leave the others growing. That is sustainability.

The chimpanzees taught me a lot about nonverbal communication. The big difference between them and us is that they don't have spoken language. Everything else is almost the same: Kissing, embracing, swaggering, shaking the fist.

My mother always taught us that if people don't agree with you, the important thing is to listen to them. But if you've listened to them carefully and you still think that you're right, then you must have the courage of your convictions.