Nova (1974–…): Season 35, Episode 5 - Ape Genius - full transcript

Are you wondering how healthy the food you are eating is? Check it -
Something strange is happening
in the forests of Africa.

Chimpanzees are doing things no
one has seen them do before:

they're in a partying mood.

But that's not all.

At a site called Fongoli,
in Senegal,

they have also invented a remarkable
way of catching a meal.

They are making spears and hunting,
just like our ancestors.

Are these apes developing human-like
skills in their own environment?

After all, the great apes-
chimpanzees, orangutans,

gorillas, and bonobos-
seem so much like us,

it's hard not to feel
a deep connection.

We have come to see that we're much more
similar to them than we ever imagined.

But for every revelation about
the power of their minds,

another shows up a
stunning difference.

If you think that human genetics and ape
genetics are 99 percent the same,

what we've managed to achieve
in our current position on Earth

is so strikingly different
from that of apes.

We're trying to figure out,
"What is it that makes us human?

What's the little difference that
makes the big difference?"

How big is the gap
between them and us?

What's holding them back?

In a remote part of Africa, there's
something new under the sun.

Our closest living relatives
are getting bold.

Chimps are supposed
to be afraid of water,

but this young male is
climbing down for a dip.

He keeps a hand on a natural safety
line as he overcomes his fear.

Has a boy or girl ever had so much
fun in a swimming hole?

Wild chimps have never before
been seen playing like this.

At Fongoli, Senegal, anthropologist Jill
Pruetz and psychologist Andrew Whiten

are getting an extraordinary
glimpse of chimp emotions.

The personality of a chimpanzee
is extremely excitable.

I've hardly ever seen a
facial expression like that.

I mean, that was extreme excitement to
the stage of kind of losing control.

It's not merely just to cool off.
The juveniles have fun.

I mean, they play in the water.
They play a lot in the water.

This is only one of a rush of discoveries

that is painting a surprising
picture of ape minds.

They are more like us than most
researchers ever imagined.

One by one, the skills and emotions we
once thought were uniquely human

are being found in apes.

Still, specific mental gaps-

the little differences that
make the big difference-

will ultimately explain why we study
them and not the other way around.

While the swimming hole is revealing
chimps' emotions in the field,

a new laboratory study is showing off
their amazing rational powers.

At the Max Planck Institute for Evolutionary
Anthropology in Leipzig, Germany,

psychologist Josep Call places
a peanut inside a clear tube.

How can the chimpanzee get the snack?

She has never seen this puzzle before.

For 10 minutes, there is
no solution in sight.

And all of a sudden, boom,
they solve it.

They have to understand that they
can use the water as a tool.

This is interesting, because the water
itself, it doesn't have any shape.

Using water as a tool seems like something
we would do... on a good day.

Another tool is being put to remarkable use
by wild chimps in their quest for a meal.

Back in Senegal, Jill Pruetz has been keeping
a close eye on chimps' eating habits.

Throughout Africa, chimps
eat almost anything,

and they have a
particular taste for meat.

Here, their favorite prey is the bush
baby, a small nocturnal primate.

But these chimps aren't catching
bush babies barehanded.

Pruetz has seen chimps making
spears and using them to hunt.

Andrew Whiten hopes to
join the ranks of the few

who have witnessed this
extraordinary behavior.

To make a spear, a chimp starts by breaking
off a branch, then sharpening the tip.

All on the quest to capture
a bush baby

in its day time sleeping hollow.

So the next step would be that
the chimp would approach the cavity

and sometimes look in,

take the tool,

jab forcefully into the
cavity, multiple times.

It may not be ice-pick-sharp,

but when driven by an arm up to five
times as strong as a human's,

it's a potentially lethal weapon.

They always either sniff it or lick it
when they withdraw the tool.

What they may do is actually break
open the entire cavity,

and if they're lucky,
find a bush baby inside.

Break, strip, sharpen, stab:

these chimps take a series of distinct
steps in a carefully premeditated hunt.

Pruetz and Whiten are
closing in on the answers.

Most of the 20 spear hunts
observed by Pruetz

have taken place during
the rainy season.

Over time she has seen
every stage of the kill.

A chimp is inspecting a hollow,
looking for a bush baby.

She breaks off a branch
and makes a spear.

The first time I saw a chimp make a tool,
I think I said something like,

"Where is she going, and what is
she going to do with that tool?"

She nibbles the tip to sharpen it.

Then, with the aid of her foot,
she aims the point into a hollow.

Pruetz has made a landmark discovery.

Never before has any
non-human species

been known to routinely make
and use deadly weapons.

So what does spear-hunting reveal
about how chimpanzees think?

Pruetz and her team have seen about half
the chimps here brandishing weapons,

which means spear hunting has
spread through much of the group.

That seems natural to us.

But generating ideas and
sharing technologies

is one scientific
definition of culture.

For Whiten, culture includes the human
arts from beer to Beethoven,

but it also covers the rudimentary
traditions of ape societies.

Whiten is trying to discover what kind
of mind can lead an ape to culture.

Young watch their parents,
sometimes very intently.

And over the following months and years,
they acquire that behavior.

So you have to be able to copy.

To prove that one ape can copy another,

a student of Andrew Whiten's
devised an experiment.

At the University of Texas,

Antoine Spiteri has built a kind
of slot machine for apes.

He loads it with a grape.

To get the fruit,

a chimp must first turn a disk to allow
the grape to drop through a hole.

Next, a chimp must move a door that
opens a handle to release the fruit pay-out.

Spiteri now trains a chimp named
Judy how to work the device.

On her own, she'd never work it out,
but thanks to a sweet liquid reward,

she learns the sequence is
two steps:


then push.

Next, Judy's group mates enter.

Spiteri wants to know if,
just by watching,

the spectators
will learn the technique.

Can these apes ape to win
this food-finding game?

One chimp seems to think she's got
it and shoves Judy aside.

A minute ago, Judy was the only
one with the knowledge.

Now another has it, and, quickly, the trick
spreads throughout the group.

But for Spiteri, the most important
question remains.

Have the next door neighbours
also learned the solution?

They have no social ties
to the original group.

In fact, they are hostile towards them.

Would they set that aside to keep
up with the Joneses next door?

In no time at all, they're working
the slot machine like old pros.

then pushing the handle.

Learning by imitation is an
essential skill for culture.

And culture, along with the complex
thoughts and emotions behind it,

was long believed
to be uniquely human.

The history of Western thought has
always been premised on the idea

that there are beasts
and there are humans;

and humans are touched by the spark
of God, and beasts are just beasts.

Something of a revolution came in 1960,
when a young researcher,

with support from the National Geographic
Society, set up camp in Tanzania.

Jane Goodall observed that chimps'
emotions seemed much like our own,

especially the tenacious bond
between mother and baby.

At a site in Western Africa,

Japanese researchers reported the
story of an ill two-year-old chimp.

Her mother touches her forehead
as if to check for a fever.

As the baby's strength ebbs
her mother remains devoted.

When I see the scene of the
mother looking at the baby,

I really recognize the emotional life of
chimpanzees are so similar to us.

For weeks after the baby's death,
the mother carries her baby's body.

Is the mother grieving?

Can an ape be in denial?

It's impossible to say exactly
what the mother is thinking,

but hard to dismiss her feelings.

Putting ape emotions on the map was just
one of Goodall's accomplishments.

She also found powerful
evidence of their intelligence.

Goodall was the first to report
chimps making and using tools-

in this case to "fish" for termites.

When she found termite-fishing,
people were so surprised,

and thought we should change
the definition of humans,

or we should include
chimpanzee as humans.

What Goodall couldn't have known was
that at a place called Goualougo,

other chimps had an even more
sophisticated way to catch termites.

First they use a big stick like a
shovel to open the ground,

then they switch to a slender
probe to pull up the insects.

Perhaps Goodall's most astonishing
discovery was that chimps are hunters.

She watched a troop catching
colobus monkeys by hand.

Although no one has established that
they coordinate their efforts,

the chimps appear to be cooperating.

And cooperation is, after all, one of the
key drivers of human culture.

Could apes speed up their culture
by working together?

Imagine a group of chimps, armed and
dangerous, hunting as a band.

So why isn't the Earth
the Planet of the Apes?

Do apes even have the
capacity to cooperate?

A series of new studies reveals the
rudiments of teamwork in the great apes.

But they still come up short.

In an experiment at the Great Ape
Research Institute in Japan,

a chimp knows that food is
hidden under a stone.

Researchers replace it
with a heavier stone.

If two chimps each know about the food,
can they work together?

In repeated trials, no pair of chimps has
ever cooperated to synchronize their pulling.

If one chimp is replaced with a person
the other animal still doesn't collaborate,

at first.

But, eventually, it figures out the
sweet rewards of cooperation.

Ultimately, the chimp learns
to ask for a helping hand.

A needy chimp may well recruit
help from a human,

but will it ever offer assistance?

One of the most surprising findings of all
of my years of studying apes

has been that they will
actually help humans.

If you're reaching for an
out-of-reach object,

if they understand what your goal is,
then they will help you.

Of course if you've dropped your banana,

you can forget it,
you won't be getting it back.

Chimps can understand
what someone else wants.

One study shows that they can even
interpret another's actions as good or bad.

In Leipzig, Germany, a chimpanzee
is about to receive a tray of food.

At the same time he's given
a rope under the platform,

he can pull at anytime to collapse
the platform and end the experiment.

Another chimp now enters the cage.

This chimp is free to pull a second
rope on top of the tray.

The first chimp is ticked off.

He pulls the hidden rope,
and the game is over.

Was he just generally outraged?

Or taking specific
revenge on the thief?

To find out, it is the researcher
that now moves the food.

Once again the first chimp has
lost his meal to the second.

All that has changed is
who is responsible.

In trials where the researcher
moves the food,

the first chimp is much less likely
to crash the platform.

That would punish an innocent chimp.

So chimps have a sense of justice,
and they can cooperate with people.

Can they collaborate
spontaneously with each other?

Researchers placed fruit on a board
just out of a chimpanzee's reach.

The chimps are behind bars
to keep them from the food,

and because they can be impulsive,
strong and dangerous.

When a solo chimp can reach both ends of a
rope, it hauls them in and gets all the food.

But on some trials the
ends are too far apart.

If the chimp pulls just one end,
the rope unthreads.

The chimp has another option.

He can unlock a door to bring in
a helper who's been watching.

The two chimps now work together.

But a series of trials shows that this
teamwork doesn't come easily.

The helper must be a friend, and the
food divided into separate dishes.

Can a more loving ape cooperate better?

At Lola Ya Bonobo
Sanctuary in the Congo,

victims of the pet trade are
raised by human mothers.

When these bonobos grow up,

they will spend their days outdoors,
becoming savvy about life in the forest.

Bonobos are the most social
of the great apes.

And in their groups, all friends
are "friends with benefits,"

a simple way to diffuse tension.

Calmer than chimps, how do bonobos
fare on the cooperation test?

Food is placed in
a central shared well.

Ok, are you ready?
One, two, three!

All the food is in the same dish,
so it's very easy for one individual

to bump the other individual out
of the way and steal it all.

It takes the bonobos a
while to get on task.

But soon they get the hang of it.

Yay, bonobos! Yay!

With their more congenial temperaments,
bonobos are more cooperative than chimps are.

In fact, bonobos may take
cooperation even further.

When a young male died at Lola Ya Bonobo,
workers were trying to remove his body.

The staff decided to use sticks and try
to move the bonobo towards a door.

They mounted an incredible
defense of this body

that surprised everybody
and was extremely moving.

That's a fascinating reaction
on the part of the bonobos.

They were not related
to that individual,

and yet, they took extreme
risks to protect his body.

As they fend off the humans,
it seems as if they're cooperating.

But what does it take to work together?

Are they comparing the number
of staff to their own troops?

Can they calculate at all?

At Kyoto University,
Tetsuro Matsuzawa's experiments

are revealing that chimps can in fact
develop an astonishing facility for numbers.

He first trained a
chimpanzee named Ai

to touch the numeral that
matched the number of dots.

Once Ai knew zero through nine,

Matsuzawa displayed the numbers
helter-skeltered on a screen.

Ai quickly learned to touch
them in ascending order.

In the final test, as soon as Ai
touches the numeral one,

white squares cover up
the remaining numbers.

Can the chimp possibly remember all the
numbers and their locations

and touch them in order?

The performance was really amazing.

Much, much better than
we had expected.

But for Ai, learning numbers
was a struggle.

Almost the same amount of training
was necessary to teach three,

teach four or teach five.

Or, even worse, it takes more time
to teach five and then six.

Ai never got the feeling
that children get

when they realize you just add
one to get to the next number.

In the United States, another ape shows
a surprising gift for language.

Going to go help get some sticks?


A bonobo named Kanzi, now at
the Great Ape Trust in Iowa,

picked up English without
being directly taught.

Put the keys in the refrigerator.

Wearing a mask to avoid cueing Kanzi,

researcher Sue Savage-Rumbaugh
tests his comprehension.

Good job!

Go get the ball that's outdoors.

Very nice. Thank you, Kanzi.

Savage-Rumbaugh measures Kanzi's
vocabulary at 3,000 spoken English words.

While apes can master
words and numbers,

other research shows that something else
is limiting their cooperation:

apes have emotional issues
-rivalry, violence-

and most of all, they're impulsive.

In a celebrated study that
investigated impulse control,

Sally Boysen of Ohio State University asked
chimps to choose between two dishes of sweets.

Now, you watch real carefully.

We're going to put one, two,
three, four down here.

Are you watching, Miss Priss?


And we're going to put two in here.

Give those to Sarah. Okay.

Well, I have to give these to Sarah,
and Sheeba gets two.

So Sarah gets four and
Sheeba only gets two.

Aw, too bad.

The twist was that the chimp got
the sweets that she didn't point to.

Could she learn to resist her
impulse to reach for the bigger pile?

You want Sarah to have these?

It's okay, it's okay.
You get to have that one.

Yeah, Sarah gets five,
and Sheba gets one.

Oh, that is such a shame.

Amazingly, in the study chimps never
overcame their greedy urges.

They always reached for more and,
so, ended up with less.

Impulse studies have also
been run on humans.

In a classic experiment
of the 1970s,

a researcher gives a
four-year-old a simple choice.

So, if you wait for me to get back,

I'll give you this bowl with all of
these gummy bears, okay?

But if you can't wait, you can
push that button, like this,

and then I'll come back and you can have this
bowl with just this one gummy bear, ok?

Okay, I'll be right back.

According to an inconclusive
but intriguing study,

the longer children
resisted temptation,

the higher their school test
results would be years later.

In any case, the differences
between people are small

compared to the gap
separating humans and apes.

Maybe one of the first things that
happened during our species evolution

is we became much less
emotionally reactive.

And maybe that's one of
the big differences

that may explain why we solve
problems so differently.

We sort of got control of our emotions.

Can apes be given skills to help
them master their emotions?

Now you watch real carefully.

Sally Boysen trained a chimp
to understand numerals.

She then repeated the experiment
with the sweets,

but offered different pairs of
numerals rather than treats.

You want to give two to Sarah? Ok.

Two goes to Sarah, and you get six.

Remarkably, chimps were now able to
learn what they couldn't before:

point in to the smaller number
to get the bigger prize.

Symbols can make you free.

They can help distance an
ape from its impulses.

But outside of the lab,
apes don't seem to use symbols.

Still, ape minds seem to share many of the
amazing features of the human mind.

They have sophisticated
social emotions.

They can cooperate.

They have culture.






Their mental rocket is
on the launch pad.

Why isn't it taking off?

On an average day, human beings
file thousands of patents,

post tens of thousands
messages over the Internet,

and think millions of thoughts that have
never been thought before.

Our closest relatives are different.

On a good day, an ape is lucky
to use a tool to crack a nut.

What prevents ape culture from
igniting like the human version?

Recent studies that compare the human and
ape mind are revealing something surprising.

Bonobos like Kanzi show
their own kind of genius.

Kanzi, could you take off Sue's shoe?

Could you take my shoe off, please?

You might need to untie it.

Even skeptics agree that Kanzi

understands more words than
any other non-human animal.

He also uses an array of visual
symbols to communicate.

But on closer inspection, Kanzi, like all
great apes, lacks the full mental package.

Take Kanzi's use of language.

Most of the time, he will use these
symbols to request things,

to say "Take me there,"
or "Give me that."

- M'nMs.
- You like M'nMs? Ok.

Now, Kanzi will not use those symbols
to talk about the weather

or to just make small talk,
which is a very human thing.

When human infants
communicate with others,

they engage in a real conversation
where each conversational turn

is responsive to the turn
that came before.

And they even ask for
clarification if they need.

So you say "Huh?" or you say "Yeah,"

and you let the other one know
how the communication is going.

To engage in a real conversation,

each speaker needs a sense of
what the other is thinking.

Call this skill mind-reading.

Young children have not
fully developed it.

Hey, so Zoe, guess what
we're going to do today?

We're going to play a game
with my Princess Sally here.

See, this is Princess Sally.
And she's got a ball that she really likes.

This is her ball.

But she needs to go
away for a little bit,

so Princess Sally is going to hide her
ball right over here in the bag.

See Princess Sally hiding her ball right
over there in the purple bag? Yeah?

So here she goes. She's going to
go away for just a little bit.

Now while Princess Sally is away, we're
going to play a little trick on her, okay?

We're going to move her ball from the
purple bag over here to the green bag.

See how we moved the ball over there?

Okay, so guess what?
Princess Sally is coming back.

Here she is. She came back.

Can you tell me, where is Princess Sally
going to first look for her ball?

Over here in the green bag?

Can you tell me,
why is Princess Sally...

Three-year-olds make consistent
mistakes about what others know.

The thing that's amazing
about three-year-olds

is how convinced they are
about their wrong answer.

They're so sure that she's going to
look for her ball where it really is

because she wants it
and that's where it is.

But by the age of four, most children are
accomplished mind-readers.

Where is Sally first going
to look for her ball?

She's going to look in the purple bag,
so she can find her ball.

She's going to look in the purple bag
so she can find her ball.

As recently as 2001,
studies seemed to show

that apes don't know what
others are thinking.

But then new experiments began
to reveal unexpected skills.

In one study, as a chimp approaches a treat,
Brian Hare moved it out of reach,

establishing himself as a competitor.

Next Hare blocks his own view of one
treats but leaves another within his sight.

It looks like they're generating a
plan and saying to themselves,

"Ok, I want that food, and the one I'm most
likely to get is the one he's not looking at,

or the one that, if I sneak
around, he won't see me,

and therefore I can have
my yummy banana treat."

This chimp seems to know
what's on Hare's mind,

what he can see and what he can't.

So chimps seem to share some of
our skills of mind-reading.

Do we have any mental skills
which are uniquely our own?

A key clue comes from a new experiment.

Back at the University of Texas,

Victoria Horner shows a chimp how to
operate a puzzle box to get a treat.

First, she taps.

Then she slots.

Next she pokes.

The chimp copies fairly
well and gets the sweet.

This game we're going to play is about
this special box I brought, alright?

There's a gummy bear. It's your turn.

Children copy the actions,
much as the chimps did.

Look, you got him. Alright!

There's the gummy bear. Good job.

The second box that I show
the chimpanzees is this one,

and it's identical to the opaque box

except that it's made out of
material which is see-through.

Only now is it obvious that the
tapping and poking don't achieve a thing:

the box has a false ceiling.

The chimps cut to the chase.

They skip the needless steps.

For the apes it's all about the treat.

What this study shows is that
apes don't just mindlessly ape.

They also understand something
more about cause and effect.

We found something quite surprising.

The children were pre-disposed to copy,

even when it meant that they were doing
something that was really rather silly.

So this seems a little like the chimps are
outsmarting the kids in this particular study.

There he is. You got him out.

Why do children imitate slavishly?

At the root of the children's behavior is
the fact that they viewed me as a grownup,

possibly as a teacher.

That children expect to be
taught is a vital difference.

While apes can copy, most researchers
believe they don't teach each other.

Learning from someone else is the
fastest way to get a new idea:

faster than learning by imitation,

faster than inventing a new
technology in the first place.

In children, a penchant for teaching appears
-even before language kicks in-

in the form of a deceptively
simple gesture: pointing.

A toddler knows that the cup being
pointed to is the one that hides a treat.

Parents love it when their
kids start pointing

because it's evidence that the kid's
trying to communicate with them.

Parents definitely notice
the difference between

babies who just point to ask for things
and babies who point to show them things.

Apes don't seem to get
that kind of pointing.

It doesn't matter whether
Brian Hare points

or stares or orients his body,

this young bonobo is unaware that
he is trying to communicate.

They were clueless at
using the information.

Even after lots and lots of trials, they
didn't use the information I provided them.

And it was a big surprise to everybody.

Pointing relies on a
particular mental skill,

a little difference that
makes a big difference.

Whenever I point, I'm actually directing
your attention towards a third object.

And you have to understand that
my attention is on that object,

and that I'm asking you, now,
to attend to the same object.

So there's sort of a triangle
between us and the object.

This mental skill, this "triangle,"
turbocharges teamwork.

What you'll see with the
human mother and baby

is that the mother is constantly
trying to show the baby what to do,

and the baby is trying to tune
into what the mother wants.

And so you have a full triangle
of mother and baby

and the thing in the environment
that they are trying to work on.

It's a special cognitive achievement.

For some reason kids do this naturally,
almost immediately.

And curiously, apes can't get into that.

At the moment we have no evidence

that apes have shared goals based
on shared commitments.

They do things together, they coordinate
their actions together,

but they don't have a shared
commitment to a shared goal.

The triangle is the core skill that
makes teaching possible.

Humans have it; apes seem to lack it.

But apes are also
missing one more thing.

It's a key emotional driver:

the passion to cheer each other on.

"Good," "good job," "well done."

This kind of facilitation, giving a hand,
encouragement, is the base of teaching.

It seems like it's not just a cognitive
capacity that's necessary for teaching.

There's this other thing,
which is wanting to teach,

that seems to be really pervasive in humans
and maybe mysteriously missing in apes.

The pieces are now coming together.

Apes have a culture, a rare achievement
in the animal world.

They can learn from each
other through imitation.

But this process is passive, often slow
and can easily backslide.

Probably there's a lot of slippage.

There's a lot of loss of
cultural innovations

between generations when you're
talking about a chimpanzee.

If an ape invents something new and
important and interesting,

maybe some others will learn it,
maybe they won't.

Unique among animals,

humans have both the passion and
mental skill to teach each other.

When you're a student rather than a
spectator, learning happens rapidly.

That's because teaching
locks in progress.

Human culture traditions
have a cumulative quality

that each generation builds on the
things of the previous generation.

So if you looked at the history of any
interesting technology,

it started out simple, and the children of
that generation learned the simple version.

But then some genius made
an improvement to it,

and everyone follows right away, and we
get this ratcheting up in complexity.

An ape may stand on
another's shoulders,

but only humans can stand on the
intellectual shoulders of giants.

It's such a great privilege to be able to
work with these animals and try to understand

what's going on in their head when they
look at you so gingerly and softly.

Is it they're thinking,
"Oh, he's such a nice guy,

and boy, I wish I knew what was
going on in his head?"

Or is she thinking,
"Gosh, what's that spot?

Is it dirt? Could I eat that?"

In spite of their limitations,

when we look into the eyes of a fellow ape,
we don't feel a gap but a deep connection.

We can't resist a chimp
reaching out for help,

or a group of unrelated bonobos rallying
to the defense of another,

or a mother refusing to let
go of her dead baby.

But as the most social of apes,

we can't help reading thoughts and feelings
into the mind behind any familiar face.

And perhaps that says more
about us than them.