On the day-long follows that I used to do with mothers and their offspring – these chimp families that I knew so well – there was hardly a day when I didn’t learn something new about them.

Even an animal, if you show genuine affection, gradually trust develops… If you always showing bad face and beating, how can you develop friendship?

We’re the only animal that wakes up and doesn’t stretch.

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.

Human language appears to be a unique phenomenon, without significant analogue in the animal world.

Some kinds of animals burrow in the ground; others do not. Some animals are nocturnal, as the owl and the bat; others use the hours of daylight. There are tame animals and wild animals. Man and the mule are always tame; the leopard and the wolf are invariably wild, and others, as the elephant, are easily tamed.

The part that always shocked me was the inter-community violence among the chimps: the patrols and the vicious attacks on strangers that lead to death. It’s an unfortunate parallel to human behavior – they have a dark side just as we do. We have less excuse, because we can deliberate, so I believe only we are capable of true calculated evil.

The chimpanzee study was – well, it’s still going on, and I think it’s taught us perhaps more than anything else to be a little humble; that we are, indeed, unique primates, we humans, but we’re simply not as different from the rest of the animal kingdom as we used to think.

My mother was determined to make us independent. When I was four years old, she stopped the car a few miles from our house and made me find my own way home across the fields. I got hopelessly lost.

Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are God. Whereas owners of cats are compelled to realize that, if you provide them with food and water and affection, they draw the conclusion that they are God.

What an ugly beast the ape, and how like us.

It was both fascinating and appalling to learn that chimpanzees were capable of hostile and territorial behavior that was not unlike certain forms of primitive human warfare.

A black cat crossing your path signifies that the animal is going somewhere.

No matter how much cats fight, there always seem to be plenty of kittens.

Bears are very nice, as long as you are nice to them.

Primate and elephant and even pig societies show considerable evidence of care for others, parent-child bonding, solidarity in the face of danger, and so on.

It disturbs me no more to find men base, unjust, or selfish than to see apes mischievous, wolves savage, or the vulture ravenous.

Man is a clever animal who behaves like an imbecile.

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

It seems strange that bears, so fond of all sorts of flesh, running the risks of guns and fires and poison, should never attack men except in defense of their young. How easily and safely a bear could pick us up as we lie asleep! Only wolves and tigers seem to have learned to hunt man for food, and perhaps sharks and crocodiles.

It is not part of a true culture to tame tigers, any more than it is to make sheep ferocious.

I love to go to the zoo. But not on Sunday. I don’t like to see the people making fun of the animals, when it should be the other way around.