Without the heart to ground it and open it to who we really can be as human beings, the brain is a very dangerous machine. A machine that is saying: we've got to have economic growth; we've got to have unending economic growth, otherwise societies will collapse. And yet there should be something saying: wait a minute, this isn't going to work.

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.

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

But let us not forget that human love and compassion are equally deeply rooted in our primate heritage, and in this sphere too our sensibilities are of a higher order of magnitude than those of chimpanzees.

Our brain is almost the same as the chimps', but we have language, we have electronic communications, we've put people on the moon - we are immensely more intelligent. And yet: how come the being with the most extraordinary intellect ever is destroying its only planet?

So long as we continued to attach more importance to our own narrow group membership than to the 'global village' we would propagate prejudice and ignorance. There was absolutely no harm in being part of a small group - indeed, with our hunter-gatherer band mentality it gave comfort, provided us with an inner circle of friends who could be utterly trusted, who were absolutely reliable. It helped give us peace of mind. The danger came only from drawing that sharp line, digging that ditch, laying that minefield, between our own group and any other group that thought differently.

I learnt from Flo how to be mother. Flo was patient, tolerant. She was supportive. She was always there. She was playful. She enjoyed having her babies, as good mothers do.