We have language and they do not. Chimps communicate by embracing, patting, looking - all these things. And they have lots of sounds. But they cannot sit and discuss. They cannot teach about things that are not present, as far as we know.

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.

When I look back over my life it's almost as if there was a plan laid out for me - from the little girl who was so passionate about animals who longed to go to Africa and whose family couldn't afford to put her through college. Everyone laughed at my dreams. I was supposed to be a secretary in Bournemouth.

Women tend to be more intuitive, or to admit to being intuitive, and maybe the hard science approach isn't so attractive. The way that science is taught is very cold. I would never have become a scientist if I had been taught like that.

You cannot share your life with a dog, as I had done in Bournemouth, or a cat, and not know perfectly well that animals have personalities and minds and feelings.

Change happens by listening and then starting a dialogue with the people who are doing something you don't believe is right.

Words can be said in bitterness and anger, and often there seems to be an element of truth in the nastiness. And words don't go away, they just echo around.

We can't leave people in abject poverty, so we need to raise the standard of living for 80% of the world's people, while bringing it down considerably for the 20% who are destroying our natural resources.

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

Chimps are very quick to have a sudden fight or aggressive episode, but they're equally as good at reconciliation.

As a small child in England, I had this dream of going to Africa. We didn't have any money and I was a girl, so everyone except my mother laughed at it. When I left school, there was no money for me to go to university, so I went to secretarial college and got a job.

I don't spend that much time being introspective, believe it or not. All I know is that I grew up not questioning God because that's how you are. God was there like the birds and the wind.

But does that mean that war and violence are inevitable? I would argue not because we have also evolved this amazingly sophisticated intellect, and we are capable of controlling our innate behavior a lot of the time.

Chimpanzees, gorillas, orangutans have been living for hundreds of thousands of years in their forest, living fantastic lives, never overpopulating, never destroying the forest. I would say that they have been in a way more successful than us as far as being in harmony with the environment.

Certainly, if you look at human behavior around the world, you have to admit that we can be very aggressive.

I think we're still in a muddle with our language, because once you get words and a spoken language it gets harder to communicate.

I'm highly political. I spend an awful lot of time in the U.S. trying to influence decision-makers. But I don't feel in tune with British politics.

It was because the chimps are so eye-catching, so like us and teach us so much that my work was recognised worldwide.

When you meet chimps you meet individual personalities. When a baby chimp looks at you it's just like a human baby. We have a responsibility to them.

I'm always pushing for human responsibility. Given that chimpanzees and many other animals are sentient and sapient, then we should treat them with respect.