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.

And what is interesting about him in relation to morality

is that he lived at a time where religion's influence was waning,

and he was sort of wondering, I think,

what would happen with society

if there was no religion or if there was less religion.

And so he painted this famous painting, "The Garden of Earthly Delights,"

which some have interpreted

as being humanity before the Fall,

or being humanity without any Fall at all.

And so it makes you wonder,

what would happen if we hadn't tasted the fruit of knowledge, so to speak,

and what kind of morality would we have?

Much later, as a student,

I went to a very different garden,

a zoological garden in Arnhem

where we keep chimpanzees.

This is me at an early age with a baby chimpanzee.

(Laughter)

And I discovered there

that the chimpanzees are very power hungry and wrote a book about it.

And at that time the focus in a lot of animal research

was on aggression and competition.

I painted a whole picture of the animal kingdom,

and humanity included,

was that deep down we are competitors,

we are aggressive,

we're all out for our own profit basically.

This is the launch of my book.

I'm not sure how well the chimpanzees read it,

but they surely seemed interested in the book.

Now in the process

of doing all this work on power and dominance

and aggression and so on,

I discovered that chimpanzees reconcile after fights.

And so what you see here is two males who have had a fight.

They ended up in a tree, and one of them holds out a hand to the other.

And about a second after I took the picture, they came together in the fork of the tree

and they kissed and embraced each other.

Now this is very interesting

because at the time everything was about competition and aggression,

and so it wouldn't make any sense.

The only thing that matters is that you win or that you lose.

But why would you reconcile after a fight?

That doesn't make any sense.

This is the way bonobos do it. Bonobos do everything with sex.

And so they also reconcile with sex.

But the principle is exactly the same.

The principle is that you have

a valuable relationship

that is damaged by conflict,

so you need to do something about it.

So my whole picture of the animal kingdom,

and including humans also,

started to change at that time.

So we have this image

in political science, economics, the humanities,

philosophy for that matter,

that man is a wolf to man.

And so deep down our nature's actually nasty.

I think it's a very unfair image for the wolf.

The wolf is, after all,

a very cooperative animal.

And that's why many of you have a dog at home,

which has all these characteristics also.

And it's really unfair to humanity,

because humanity is actually much more cooperative and empathic

than given credit for.

So I started getting interested in those issues

and studying that in other animals.

So these are the pillars of morality.

If you ask anyone, "What is morality based on?"

these are the two factors that always come out.

One is reciprocity,

and associated with it is a sense of justice and a sense of fairness.

And the other one is empathy and compassion.

And human morality is more than this,

but if you would remove these two pillars,

there would be not much remaining I think.

And so they're absolutely essential.

So let me give you a few examples here.

This is a very old video from the Yerkes Primate Center

where they train chimpanzees to cooperate.

So this is already about a hundred years ago

that we were doing experiments on cooperation.

What you have here is two young chimpanzees who have a box,

and the box is too heavy for one chimp to pull in.

And of course, there's food on the box.

Otherwise they wouldn't be pulling so hard.

And so they're bringing in the box.

And you can see that they're synchronized.

You can see that they work together, they pull at the same moment.

It's already a big advance over many other animals

who wouldn't be able to do that.

And now you're going to get a more interesting picture,

because now one of the two chimps has been fed.

So one of the two is not really interested

in the task anymore.

(Laughter)

(Laughter)

(Laughter)

Now look at what happens at the very end of this.

(Laughter)

He takes basically everything.

(Laughter)

So there are two interesting parts about this.

One is that the chimp on the right

has a full understanding he needs the partner --

so a full understanding of the need for cooperation.

The second one is that the partner is willing to work

even though he's not interested in the food.

Why would that be? Well that probably has to do with reciprocity.

There's actually a lot of evidence in primates and other animals

that they return favors.

So he will get a return favor

at some point in the future.

And so that's how this all operates.

We do the same task with elephants.

Now with elephants, it's very dangerous to work with elephants.

Another problem with elephants

is that you cannot make an apparatus

that is too heavy for a single elephant.

Now you can probably make it,

but it's going to be a pretty flimsy apparatus I think.

And so what we did in that case --

we do these studies in Thailand for Josh Plotnik --

is we have an apparatus around which there is a rope, a single rope.

And if you pull on this side of the rope,

the rope disappears on the other side.

So two elephants need to pick it up at exactly the same time and pull.

Otherwise nothing is going to happen

and the rope disappears.

And the first tape you're going to see

is two elephants who are released together

arrive at the apparatus.

The apparatus is on the left with food on it.

And so they come together, they arrive together,

they pick it up together and they pull together.

So it's actually fairly simple for them.

There they are.

And so that's how they bring it in.

But now we're going to make it more difficult.

Because the whole purpose of this experiment

is to see how well they understand cooperation.

Do they understand that as well as the chimps, for example?

And so what we do in the next step

is we release one elephant before the other,

and that elephant needs to be smart enough

to stay there and wait and not pull at the rope --

because if he pulls at the rope, it disappears and the whole test is over.

Now this elephant does something illegal

that we did not teach it.

But it shows the understanding that he has,

because he puts his big foot on the rope,

stands on the rope and waits there for the other,

and then the other is going to do all the work for him.

So it's what we call freeloading.

(Laughter)

But it shows the intelligence that the elephants have.

They develop several of these alternative techniques

that we did not approve of necessarily.

So the other elephant is now coming

and is going to pull it in.

Now look at the other. The other doesn't forget to eat, of course.

(Laughter)

This was the cooperation, reciprocity part.

Now something on empathy.

Empathy is my main topic at the moment of research.

And empathy has sort of two qualities.

One is the understanding part of it. This is just a regular definition:

the ability to understand and share the feelings of another.

And the emotional part.

And so empathy has basically two channels.

One is the body channel.

If you talk with a sad person,

you're going to adopt a sad expression and a sad posture,

and before you know it you feel sad.

And that's sort of the body channel of emotional empathy,

which many animals have.

Your average dog has that also.

That's actually why people keep mammals in the home

and not turtles or snakes or something like that

who don't have that kind of empathy.

And then there's a cognitive channel,

which is more that you can take the perspective of somebody else.

And that's more limited.

There's few animals -- I think elephants and apes can do that kind of thing --

but there are very few animals who can do that.

So synchronization,

which is part of that whole empathy mechanism

is a very old one in the animal kingdom.

And in humans, of course, we can study that

with yawn contagion.

Humans yawn when others yawn.

And it's related to empathy.

It activates the same areas in the brain.

Also, we know that people who have a lot of yawn contagion

are highly empathic.

People who have problems with empathy, such as autistic children,

they don't have yawn contagion.

So it is connected.

And we study that in our chimpanzees by presenting them with an animated head.

So that's what you see on the upper-left,

an animated head that yawns.

And there's a chimpanzee watching,

an actual real chimpanzee watching a computer screen

on which we play these animations.

(Laughter)

So yawn contagion

that you're probably all familiar with --

and maybe you're going to start yawning soon now --

is something that we share with other animals.

And that's related to that whole body channel of synchronization

that underlies empathy

and that is universal in the mammals basically.

Now we also study more complex expressions. This is consolation.

This is a male chimpanzee who has lost a fight and he's screaming,

and a juvenile comes over and puts an arm around him

and calms him down.

That's consolation. It's very similar to human consolation.

And consolation behavior,

it's empathy driven.

Actually the way to study empathy in human children

is to instruct a family member to act distressed,

and then they see what young children do.

And so it is related to empathy,

and that's the kind of expressions we look at.

We also recently published an experiment you may have heard about.

It's on altruism and chimpanzees

where the question is, do chimpanzees care

about the welfare of somebody else?

And for decades it had been assumed

that only humans can do that,

that only humans worry about the welfare of somebody else.

Now we did a very simple experiment.

We do that on chimpanzees that live in Lawrenceville,

in the field station of Yerkes.

And so that's how they live.

And we call them into a room and do experiments with them.

In this case, we put two chimpanzees side-by-side.

and one has a bucket full of tokens, and the tokens have different meanings.