Frans de Waal

The primate laugh is given in playful contexts, and as such has a strong similarity to the human laugh.

Exclusive homosexuality is not very common in nature.

Male bonobos really don't fit the human male ideal.

There has been so much underestimating of animal cognition that to perhaps overestimate it, as I probably do, is probably a healthy reaction.

Although elephants are far more distantly related to us than the great apes, they seem to have evolved similar social and cognitive capacities.

Many economists are great believers in the idea that everything in nature is competitive and that we should set up a society which is competitive to reflect that. Anyone who cannot keep up, well, too bad.

The more self-aware an animal is, the more empathetic it tends to be.

We need to separate the process of evolution - which is, indeed, a self-serving process - and the actual motivations of animals.

There are many reasons for kindness, and religion is just one of them.

Understanding the need for religion is a far superior goal to bashing it.

A chimpanzee who is really gearing up for a fight doesn't waste time with gestures but just goes ahead and attacks.

I think we need to start thinking about grounding our moral systems in our biology.

Female bonobos form a strong sisterhood. They rule through female solidarity.

When humans behave murderously, such as inflicting senseless slaughter of innocents in warfare, we like to blame it on some dark, 'animalistic' instinct.

Chimpanzees have very strong preferences and aversions that are completely personality-linked. The people who are unsuccessful in working with chimpanzees are those who take this personally.

In Africa, we have the bush meat trade, which means that, on a very large scale, animals are being killed in the forests and sold in the cities as a luxury food.

Chimpanzees, typically, kiss and embrace after fights. They first make eye contact from a distance to see the mood of the others. Then they approach and kiss and embrace.

Science is not inherently good.

Following rules is, of course, the reason the dog is man's best friend is because the dog follows rules, and they actually do experiments on that, is that how well certain breeds of dogs follow rules, and how much they internalize them. And so many hierarchical animals, obviously they follow rules.

Future benefits rarely figure in the minds of animals.

Most exotic animals are not particularly interested in people, which makes it hard to provoke them. Human-rearing gets them used to and sometimes imprinted on humans, which makes them potentially dangerous.

I am personally not against keeping animals at zoos, as they serve a huge educational purpose, but treating them well and with respect seems the least we could do, and with 'we' I mean not just zoo staff, but most certainly also the public.

It is hard to get animals which normally pay little attention to each other to do things together. One can teach dolphins to jump simultaneously out of the water precisely because they show similar behavior spontaneously, but try to make two domestic cats jump together and you will fail.

The sturdiest pillars of human morality are compassion and a sense of justice.

Dogmatists have one advantage: they are poor listeners.

Religion looms as large as an elephant in the United States, to the point that being nonreligious is about the biggest handicap a politician running for office can have, bigger than being gay, unmarried, thrice married, or black.

I was too restless as a boy to sit through an entire mass. It was akin to aversion training. I looked at it like a puppet show with a totally predictable story line. The only aspect I really liked was the music.

I was raised Catholic. Not just a little bit Catholic, like my wife, Catherine. When she was young, many Catholics in France already barely went to church, except for the big three: baptism, marriage, and funeral. And only the middle one was by choice.

The whole reason people fill their homes with furry carnivores and not with, say, iguanas and turtles, is because mammals offer something no reptile ever will. They give affection, they want affection, and respond to our emotions the way we do to theirs.

There are beautiful examples of art done by chimpanzees in human care.

Deep down, creationists realize they will never win factual arguments with science. This is why they have construed their own science-like universe, known as Intelligent Design, and eagerly jump on every tidbit of information that seems to go their way.

Popular culture bombards us with examples of animals being humanized for all sorts of purposes, ranging from education to entertainment to satire to propaganda. Walt Disney, for example, made us forget that Mickey is a mouse, and Donald a duck. George Orwell laid a cover of human societal ills over a population of livestock.

I was born in Den Bosch, where the painter Hieronymus Bosch named himself after. And so I've always been very fond of this painter who lived and worked in the 15th century.

Unlike the primate hand, the elephant's grasping organ is also its nose. Elephants use their trunks not only to reach food but also to sniff and touch it. With their unparalleled sense of smell, the animals know exactly what they are going for. Vision is secondary.

The intuitive connection children feel with animals can be a tremendous source of joy. The unconditional love received from pets, and the lack of artifice in the relationship, contrast sharply with the much trickier dealings with members of their own species.

One thing bothered me as a student. In the 1960s, human behavior was totally off limits for the biologist. There was animal behavior, then there was a long time nothing, after which came human behavior as a totally separate category best left to a different group of scientists.

Closeness to animals creates the desire to understand them, and not just a little piece of them, but the whole animal. It makes us wonder what goes on in their heads even though we fully realize that the answer can only be approximated.

Scientists are supposed to study animals in a totally objective fashion, similar to the way we inspect a rock or measure the circumference of a tree trunk. Emotions are not to interfere with the assessment. The animal-rights movement capitalizes on this perception, depicting scientists as devoid of compassion.

The fact that the apes exist and that we can study them is extremely important and makes us reflect on ourselves and our human nature. In that sense alone, you need to protect the apes.

If there is any form of contagion that is adaptive, it is the immediate response to the fear of others. If others are fearful, there may be good reason for you to be fearful too.

If you look at national economies today, for example, the American economy, the European economy, the Indians, the Chinese, we're all tied together. If one of them sinks, the rest are going to sink with them and if one floats, the rest are lifted up. I find that very interesting.

After World War II it was decided that, in order to prevent the Germans and the French from having another war, it would be better to tie them together into one economic pact so they would invest in each other and have mutual stakes. Until now, that has worked to prevent warfare between the two.

I think the sense of fairness in humans is very strongly developed, and that's why we react so strongly to all the bonuses received by Wall Street executives. We want to know why they deserve these benefits.

You should know as much as you can about the human species if you have a hand in designing human society.

Personally, I think it is possible to build a society that is moral on a nonreligious basis, but the jury is still out on that.

I'm personally a nonbeliever, so I'm struggling with if we really need religion.

Religion may have become a codification of morality, and it may fortify it, but it's not the origin of it.

Very long ago our ancestors had moral systems. Our current institutions are only a couple of thousand years old, which is really not old in the eyes of a biologist.

Chimps don't have language. Humans actively instruct others about how things should be done. Chimpanzees probably pick up cultural traditions by observation.

Chimps cannot tell us anything about peaceful relations, because chimps have only different degrees of hostility between communities. Whereas bonobos do tell us something; they tell us about the possibility of having peaceful relationships.