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- [Narrator] We are the Paradoxical Ape.
Bipedal,
naked,
large brain.
Long the master of fire,
tools and language,
but still trying to understand ourselves.
Aware that death is inevitable,
yet filled with optimism.
We grow up slowly.
We hand down knowledge.
We empathize and deceive.
We shape the future
from our shared understanding of the past.
Carta brings together experts
from diverse disciplines
to exchange insights
on who we are,
and how we got here.
An exploration made possible
by the generosity of humans
like you.
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- It's my great pleasure to talk about
my study on chimpanzees.
Today I will talk about teaching.
Teaching of chimpanzees is called
education by master-apprenticeship.
Outline of my talk.
First I will talk about mother-infant relationship,
then let me proceed to the tool use in the wild,
and finally,
I will talk about laboratory simulation.
What is uniquely human?
Mother-infant relationship is very unique.
This is phylogeny of primates.
Human is a species of hominid,
that include chimpanzees,
mother and infant.
Bonobos,
mother and infant.
I will show you bonobo.
(crickets chirping)
(monkeys squealing)
I visited Wamba,
Congo Zaire,
to see the bonobos.
And gorillas,
again mother and infant
and father.
I will show you a gorilla father called silverback.
(crunching)
They live on grasses,
herbs.
And orangutan,
again mother and infant.
I also visited humans,
hunter-gatherers
in Cameroon.
The person next to me
has a big family,
and the right most,
her eldest daughter has already has a baby.
This means he's grandfather,
and his wife is grandmother.
Grandmother link is very unique to the humans.
So in short human society is unique,
because of multi-level society of family
and community.
And collaboration in among the members of the community,
sharing that makes us human.
Let me proceed to the tool use in the wild.
My field observation is done in Bossou, Guinea-Conakry,
since 1986.
This is a forest of chimpanzees in Bossou.
You can see our field station of Kyoto University.
That is a so so large village,
and surrounding forest,
that is the high mart,
the home place of wild chimpanzees of Bossou.
I have been focusing on the tool use.
Chimpanzee of Bossou use a pair of stones
to crack open nuts.
That is a unique cultural tradition.
(crickets chirping)
This is another female chimpanzee.
(crickets chirping)
Pick up a nut,
hard shelled nut.
Hit,
crack it open,
till you get to the kernel,
edible part.
Oh by the way she's left-handed.
Always using her left-hand for hammering.
It takes four, five years
to reach to this level,
where start cracking nuts.
So this is three years and a half,
a young chimpanzee,
she cannot do it.
How will she do?
(birds chirping)
She goes to sees the nearby adult,
and he carefully look at what's going on.
Interestingly, no active teaching at all,
nothing.
A young chimpanzee,
return to her home place
to try to do
nut cracking by herself.
(birds chirping)
This is the way of teaching.
This is the way of education in chimpanzees.
There is a very few cases in which it looks like a teaching.
So this is an grandmother,
is trying to crack open nut in front of grandson.
By the way,
grandmother link is very rare in chimpanzees.
I want to show you another example of tool use in the wild.
Scooping algae.
This was found in Bossou,
25 years ago.
Standing at the edge of the small pond,
each chimpanzee was holding a stalk or stick
in one hand,
and this is a digital holotype.
It's a first video recoding 25 years ago,
in 1995,
using stick to get algae floating on the pond.
You can see the manufacturing process.
Uproot a fern,
and cut into the right length side about 50 centimeter long,
and stripping the side leaves,
to leave the tiny hooks on the stem.
That's great for scooping algae.
This is what I have witnessed in the wild.
Chimpanzee tool use,
throughout Africa,
make a long long list,
of variety of tools.
But,
according to my level's theory of tool use,
almost all tool use by wild chimpanzees
is classified level 1 tool.
Level one
means one node connect two different objects,
target object and tool.
So ant and stick,
ant dipping,
and RG and stick
for RG scooping for termite,
and aah,
probing stick,
probes to termite fishing.
So almost all belong to a level one.
So nut cracking is a layer case of Level 2 tool.
Nut,
anvil, hammer,
is combined by
pressing
and hitting.
And level 3 tool is the most complex tool
so far in the wild,
use of wedge.
So this is a hammer and anvil,
and the third stone wedge,
is used for stabilizing
and keeps the anvil surface flat.
This is the most complex tool use in the wild.
The question is how to teach,
or how to aah,
transmit this knowledge and technique,
from one generation to the next.
And that process is named
education by master-apprenticeship,
that has three features,
mothers and other adults serve as models of the behavior.
Second,
the apprentice,
the offspring,
is strongly motivated to copy
the behavior,
intrinsic motivation,
no food reward.
And the third,
in return,
the mothers and adults
are highly tolerant of the apprentice,
so around the tool use site.
So this is education by master-apprenticeship.
Human way of education,
is eliminated through chimpanzees.
Three features,
active teaching,
verbal instruction,
coaching, molding, guidance,
suggestion, tutoring, scafording.
But there is a subtle way of education to uniquely human.
That is helping,
giving a hand,
social praise,
nodding,
smiling,
nothing to do except just monitoring,
just watching.
And finally,
collaborative education.
Not only mother,
father,
grandmother,
older members of the community,
is embodied to in the education.
Let me proceed to the final part
that is simulation in the laboratory.
Under my mentors is David Premack.
He is a pioneer of teaching plastic sign language
to a chimpanzee Sarah.
So chimpanzees
and bonobos,
Kanzi,
learned lexigrams and spoken language.
And gorillas,
Koko,
learned American Sign Languages.
So those ape language studies,
told us that,
if you teach they can learn.
So in my case laboratory study is called Ai project,
since 1977.
And up to that point,
classic way of studying apes is cross fostering.
Isolate a baby chimpanzee from the mother,
and I recognize,
it's not good because,
infant isolated from the mother
looks like depressive.
So when Ai chimpanzee gave the birth to her son
named Ayumu in 2000,
I strongly decided
not to separate the baby chimpanzee from the mother.
So what I called participant observation.
I participated in their daily life
of mother and infant,
who are living in a group of chimpanzees.
So this is my way of studying chimpanzees.
Multiple habitats are interconnected
for the simulation of fishing fusion
group-living chimpanzees,
in the Primate Research Institute.
So in a face-to-face situation,
I did the nesting cup,
the cognitive test.
Seven cups,
small to large.
Three to four,
four to five,
aah.
Six to seven,
three, four, five,
one.
And stacking blocks.
So mother stack blocks,
and,
it is spontaneously imitated
by the young chimpanzees.
So we taught mother chimpanzees
but we did not teach the youngsters.
Mother has learned to use the letters.
Color red go to the letter.
Color blue,
goes to the letter.
Color purple.
Gray is a reversed task,
now decoding the letter.
Yellow,
what is this letter?
Green.
And it is brown.
So,
right after the birth,
the baby chimpanzee was always with the mother
doing this kind of cognitive tests.
Solving the matching to sample task,
to get the coin,
and put it into the vending machine.
And that,
was learned by the baby chimpanzee.
A coin is delivered for each correct answer.
Then Ayumu brings a coin into the vending machine.
So,
the whole process in this case in the laboratories,
that is solving matching to sample,
and to get the coin,
to use a vending machine,
to get the food reward.
The entire process was imitated,
learned,
by education master apprenticeship.
Okay.
Ayumu Chimpanzees learns a sequence of a numeral,
just like mother chimpanzees.
So based on this knowledge,
we tested their working memory.
We have three young chimpanzees,
and they can do the task like this,
what we call masking task.
So first,
stimuli numeral is touched,
the others are masked.
(finger tapping)
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So I postulated the Cognitive Tradeoff Hypothesis.
The common ancestor may have the,
this kind of capability,
but we lost it,
in the course of human evolution.
In return,
we acquire the language.
Please go to YouTube
and put Matsuzawa and Tradeoff.
There are more than 15 medium Nexis,
and you can see the detail of the explanation.
So,
beyond teaching,
chimpanzee can show us their capability,
a unique capability,
that is somehow different from humans.
Thank you very much for my colleagues
and staffs in the laboratory work.
And thank you very much for the colleagues
in my fieldwork.
And thank you for your attention.
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