My own book was also...The Naked Ape was published by Jonathan Cape, and this book got me into all sorts of trouble. A zoologist wasn't supposed to write about human beings. And, worse still, the zoologist was writing about them as though they were just another kind of animal. The chapter headings in The Naked Ape were almost the same as the ones in my thesis on sticklebacks. There's a chapter on feeding behaviour, fighting behaviour, mating behaviour, parental behaviour – the same things that I'd studied in fish. And what made The Naked Ape an unusual book was that it was written just as... the same way that I would write about other animals. And I said at the beginning that I'm going to ignore all the higher achievements of human beings that people usually write about and I'm going to look at his basic ones – I'm only going to look at things we share with other animal like feeding and mating and fighting. I'm not going to look at literature and art and science and research and philosophy and politics. I'm not going to look at any of that. I'm going to ignore all that and just say: what do we share with other animals?

And it was clear to me that it'd be very foolish of any species to throw away genetic background. And it was clear to me that a lot of the behaviour patterns that we performed were inborn or had a very strong inborn influence. I didn't want to suggest that we had genetic instructions in our behaviour. We certainly had genetic instructions in our anatomy and our physiology, obviously. But in our behaviour, at the time I wrote The Naked Ape, everyone said that we were born as a tabula rasa, as a blank sheet on which education wrote everything, so that our entire personalities were based on what we learnt during our lifetime and that, when we started out, we were just blank sheets.

Now I thought this can't be true because no species is going to throw away all the achievements that have occurred during its evolution. Because what happens during the course of evolution is that certain patterns of behaviour turn out to be more successful than others, and they're selected, and that must apply to us. And so I wrote about patterns of behaviour that seemed to me to be inborn not as genetic instructions, but as genetic suggestions – there's a difference, you see. What happens is that you inherit a genetic suggestion that this is the best way to do something. But then you are able, because you're a... one of your genetic suggestions is that you should be very innovative and playful because we are a very playful species. Adult play is what we call science and art and all those wonderful things that human beings do. But they're all essentially to do with curiosity and invention and innovation and exploring new ideas and new things and that, we're very, very good at. So there's a flexibility in our behaviour.

But there are a number of basic suggestions of... that this is... our genes tell us that this is the best way to do a particular thing, and we can vary from that, but if we vary too far away from that, we're in trouble. And every so often, a particular movement or cult or belief system will develop which interferes with those basic biological suggestions. And I made the point that The Naked Ape is at his most fulfilled when he keeps reasonably close to those basic suggestions and doesn't stray too far from them. Because if he does stray too far from those evolutionary suggestions, then it won't be appropriate – his behaviour will not be appropriate for his species.