Professor Paul Bloom:
So, most of what we do these
days – our methods,
our theories,
our ideas – are shaped,
to some extent,
by Piaget's influence.
And so, what I want to do is
begin this class that's going to
talk about cognitive development
by talking about his ideas.
His idea was that children are
active thinkers;
they're trying to figure out
the world.
He often described them as
little scientists.
And incidentally,
to know where he's coming from
on this, he had a very dramatic
and ambitious goal.
He didn't start off because he
was interested in children.
He started off because he was
interested in the emergence of
knowledge in general.
It was a discipline he
described as genetic
epistemology – the origins of
knowledge.
But he studied development of
the individual child because he
was convinced that this
development will tell him about
the development of knowledge
more generally.
There's a very snooty phrase
that--I don't know if you ever
heard it before.
It's a great phrase.
It's "Ontogeny recapitulates
phylogeny."
And the idea of this--What that
means is that development of an
individual mimics or repeats
development of the species.
Now, it's entirely not true,
but it's a beautiful phrase and
Piaget was committed to this.
He was very interested in
saying, "Look.
We'll figure how a kid develops
and that will tell us about the
development of knowledge more
generally."
So, Piaget viewed the child as
a scientist who developed this
understanding,
these schemas,
these little,
miniature theories of the
world.
And they did this through two
sorts of mechanisms:
assimilation and accommodation.
So, assimilation would be the
act of expanding the range of
things that you respond to.
Piaget's example would be a
baby who's used to sucking on a
breast might come to suck on a
bottle or on a rattle.
That's changing the scope of
things that you respond to.
Accommodation is changing how
you do it.
A baby will form his mouth
differently depending on what
he's sucking on.
And so, these processes where
you take in--I'm giving this in
a very physical way,
but in a more psychological
sense you have a way of looking
at the world.
You could expand it to
encompass new things,
assimilation.
But you could also change your
system of knowledge itself –
accommodation.
And Piaget argued that these
two mechanisms of learning drove
the child through different
stages.
And he had a stage theory,
which was quite different from
the Freudian stage theory that
we have been introduced to.
So his methods were to ask
children to solve problems and
to ask them questions.
And his discoveries that--they
did them in different ways at
different ages led to the
emergence of the Stage Theory.
So, for Piaget,
the first stage is the
sensorimotor stage or the
sensorimotor period.
For here the child is purely a
physical creature.
The child has no understanding
in any real way of the external
world.
There's no understanding of the
past, no understanding of the
future, no stability,
no differentiation.
The child just touches and
sees, but doesn't yet reason.
And it's through this stage
that a child gradually comes to
acquire object permanence.
Object permanence is the
understanding that things exist
when you no longer see them.
So those of you in front,
you're looking at me and I go.
It occurred to me it'd be a
great magic trick if I then
appeared in back.
But no, I'm just here.
That's object permanence.
If I went under here and then
the people said,
"Where the hell did he go?
Class is over," that would show
a lack of object permanence.
So, adults have object
permanence.
Piaget's very interesting claim
is that kids don't.
Before six-month-olds,
Piaget observed,
you take an object the kid
likes like a rattle,
you hide it,
you put it behind something,
it's like it's gone.
And he claimed the child really
thinks it's just gone.
Things don't continue to exist
when I'm not looking at them
anymore.
And so he noticed they--they're
surprised by peek-a-boo.
And Piaget's claim was one
reason why they're surprised at
peek-a-boo is you go--you look
at a kid,
the kid's smiling and go,
"Oh, peek-a-boo," and you
close--and you cover your face
and the kid says,
"He's gone."
"Peek-a-boo."
"Oh, there he is.
He's gone."
And you really--That's the
claim.
Piaget also discovered that
older children fail at a task
that's known as the A-not-B
task.
And Peter Gray in his
psychology textbook refers to it
as the "changing hiding places"
problem, which is probably a
better name for it.
And here's the idea.
You take a nine-month-old and
for Piaget a nine-month-old is
just starting to make sense of
objects and their permanence.
You take an object and you put
it here in a cup where the kid
can't see it,
but it's in the cup.
So the kid, if you were the
kid, will reach for it.
You do it again, reach for it.
You do it again, reach for it.
That's point A.
Then you take--you move it over
here.
Piaget observed kids would
still reach for this.
It's like they're not smart
enough to figure out that it's
not there anymore,
even if they see it move.
And this was more evidence that
they just don't understand
objects, and that this thing
takes a lot of time and learning
to develop.
The next stage is the
preoperational stage.
The child starts off grasping
the world only in a physical
way, in a sensorimotor way,
but when he gets to the
preoperational period the
capacity to represent the world,
to have the world inside your
head, comes into being.
But it's limited and it's
limited in a couple of striking
ways.
One way in which it's limited
is that children are egocentric.
Now, egocentrism has a meaning
in common English which means to
be selfish.
Piaget meant it in a more
technical way.
He claimed that children at
this age literally can't
understand that others can see
the world differently from them.
So, one of his demonstrations
was the three mountains task.
We have three mountains over
there.
You put a child on one side of
the mountains and you ask him to
draw it, and a four- or
five-year-old can do it easily,
but then you ask him to draw it
as it would appear from the
other side and children find
this extraordinarily difficult.
They find it very difficult to
grasp the world as another
person might see it.
Another significant finding
Piaget had about this phase of
development concerns what's
called "conservation."
The notion of conservation is
that there's ways to transform
things such that some aspects of
them change but others remain
the same.
So, for instance,
if you take a glass of water
and you pour it into another
glass that's shallow or tall,
it won't change the amount of
water you have.
If you take a bunch of pennies
and you spread them out,
you don't get more pennies.
But kids, according to Piaget,
don't know that and this is one
of the real cool demonstrations.
Any of you who have access to a
four- or five-year-old,
[laughter]
a sibling or something--Do not
take one without permission,
but if you have access to a
four- or five-year-old you can
do this yourself.
This is what it looks like.
The first one has no sound.
The second one is going to be
sound that's going to come on at
the end.
But there's two rows of
checkers.
She asks the kid which one has
more.
The kid says they're the same.
Then she says--Now she asks him
which one has more,
that or that.
So that's really stupid.
And it's an amazing finding
kids will do that and it's a
robust finding.
Here's another example.
So, they're the same.
So, it's a cool finding of that
stage, suggesting a limitation
in how you deal and make sense
of the world.
The next phase,
concrete operations,
from seven to twelve,
you can solve the conservation
problem,
but still you're limited to the
extent you're capable of
abstract reasoning.
So the mathematical notions of
infinity or logical notions like
logical entailment are beyond a
child of this age.
The child is able to do a lot,
but still it's to some extent
stuck in the concrete world.
And then finally,
at around age twelve,
you could get abstract and
scientific reasoning.
And this is the Piagetian
theory in very brief form.
Now, Piaget fared a lot better
than did Freud or Skinner for
several reasons.
One reason is these are
interesting and falsifiable
claims about child development.
So claims that--about the
failure of conservation in
children at different ages could
be easily tested and
systematically tested,
and in fact,
there's a lot of support for
them.
Piaget had a rich theoretical
framework, pulling together all
sorts of observations in
different ways,
wrote many, many books and
articles and articulated his
theory very richly.
And most of all,
I think, he had some really
striking findings.
Before Piaget,
nobody noticed these
conservation findings.
Before Piaget,
nobody noticed that babies had
this problem tracking and
understanding objects.
At the same time,
however, there are limitations
in Piaget's theory.
Some of these limitations are
theoretical.
It's an interesting question as
to whether he really explains
how a child goes from a concrete
thinker to an abstract thinker,
or how he goes from not having
object permanence to
understanding object permanence.
There's methodological
limitations.
Piaget was really big into
question and answer,
but one problem with this is
that children aren't very good
with language,
and this might lead you to
underestimate how much they
know.
And this is particularly a
problem the younger you get.
Methodology is going to loom
heavy in the discussion of any
science and that includes
psychology.
Often 90% of the game is
discovering a clever method
through which to test your
hypotheses.
We're going to talk a little
bit about that regarding babies.
I'll give you another example
from a very different domain.
There was a set of scientists
interested in studying tickling.
So, when you tickle somebody,
under what circumstances will
they laugh?
Where do you have to tickle
them?
Can you tickle yourself?
Does it have to be a surprise,
and so on?
It turns out very difficult to
study this in a lab.
You're not going to have your
experimental credit.
You come into the lab and say,
"Okay.
I'm the graduate student.
Ha, ha, ha."
And [laughter]
in fact, an example of a
methodological attempt was done
by Henry Gleitman at University
of Pennsylvania,
who built a tickle machine,
which was this box with these
two giant hands that went
"r-r-r-r."
This was a failure because
people could not go near the
tickle machine without
convulsing in laughter.
But we will discuss when we
have a lecture on laughter a bit
of the tickle sciences.
And finally there's factual.
What do infants and children
really know?
It's possible that due to the
methodological limitations of
Piaget, he systematically
underestimated what children and
babies know.
And in fact,
I'll present some evidence
suggesting that this is in
fact--that this is the case.
So, I want to introduce you to
the modern science of infant
cognition.
Infant cognition has been
something studied for a very
long time.
And there was a certain view
that has had behind it a
tremendous philosophical and
psychological consensus.
And it's summarized in this
Onion headline here.
And the idea is that babies are
stupid, that babies really don't
know much about the world.
Now, the work that this
Onion headline is
satirizing is the recent
studies,
which I'm going to talk about,
suggested that on the contrary,
babies might be smarter than
you think.
And to discover the
intelligence of babies we have
to ourselves be pretty smart in
developing different techniques.
To study what a baby knows,
you can't ask your questions.
Babies can't talk.
You could look at what it does
but babies are not very
coordinated or skilled so you
need to use clever methods.
One clever method is to look at
their brain waves [laughter].
This child on the right died
during testing.
It was a tragic--It was crushed
by the weights [laughter]
of the electrodes.
He's happy though.
You could study their brain
waves.
One of the few things babies
can do is they could suck on a
pacifier.
And you might think,
well, how could you learn
anything from that?
Well, for instance,
you could build machines that
when babies suck on a pacifier
they hear music or they hear
language,
and then you could look at how
much they suck on the pacifier
to determine what they like.
But undeniably we know most of
our--we got most of our
knowledge about babies from
studies of their looking times.
That's one thing babies can do.
They can look.
And I have up here--This is a
picture of Elizabeth Spelke,
who is a developmental
psychologist who's developed the
most research on looking at
babies' looking times and what
you could learn from them.
And I have here two ways you
could learn from looking.
One is preference.
So for instance,
suppose you want to know,
for whatever reason,
do babies like the looks of
dogs or cats?
Well, you could put a baby
down, have a picture of a dog
here, a picture of a cat here,
and see which one the baby
looks at.
Babies can move their eyes and
that could tell you something.
Do babies distinguish pretty
faces from ugly faces?
Well, put a pretty face here,
an ugly face here,
see if the baby prefers to look
at the pretty one.
You could also do habituation
and surprise.
And much of the studies I'm
going to talk about here involve
habituation and surprise.
Habituation is a fancy word for
boredom.
What you do is you show a baby
something over and over again.
Now, remember from behaviorism
the baby will learn this isn't
very interesting.
Then you show the baby
something different.
If the baby really sees it as
different, the baby will look
longer, and you could use that
as a measure of what babies find
different.
For instance,
suppose you want to know if the
baby can tell green from red.
Well, you could show the baby a
green patch, a green patch,
a green patch,
a green patch;
the baby'll get bored,
then a red patch.
If they all look the same to
the baby, the baby will just
continue to tune out,
but if the red looks different
the baby will perk up.
And this is,
in fact, one way they study
color vision in babies.
Surprise is related to this.
You could show babies something
that shouldn't happen.
If babies are like--If babies
also think it shouldn't happen,
they might look longer,
and essentially what happens is
scientists do magic tricks to
explore this very thing.
And to start with some real
examples, a lot of this infant
research has gone back to the
Piagetian question of object
permanence,
asking, "Is it really true
babies don't know that objects
remain even when they're out of
sight?"
So one very simple study by
Spelke and Baillargeon:
Have babies shown a block with
a bar going back and forth like
that.
So the bar just goes back and
forth.
Now, there's something you do
that's so obvious you probably
don't even know you're doing it.
When you see a display like
that, what you assume is there's
a bar there, and what that means
is there's something in the
middle that you've never seen
before.
But of course,
if you were a simple perceptual
creature, you would just see
that there'd be a bar on top and
a bar on the bottom.
You wouldn't expect anything in
the middle because you never saw
anything in the middle.
So, what you do then is you
show babies this and then you
show them either B or C and if
we do this with adults you
expect B, C is almost a joke.
And, in fact,
babies respond the same way.
Babies expect there to be an
entire, complete bar and are
surprised and look longer at the
broken bar.
Other studies,
some of them--Well,
here's another study by Rene
Baillargeon looking at the same
thing in a different way.
You show the baby,
say a six-month-old,
a stage with a block on it.
Then a screen rises and
obscures the block.
Now, if the babies expect the
block to still be there,
they should think the block
should stop the screen.
On the other hand,
if out of sight out of mind,
they should expect the screen
to keep going.
So, what you do is you set up a
couple of displays,
one where the block is stopped,
the other one where you take
this away with a trap door and
it keeps going.
And, as you see,
the baby screams when this
happens.
That doesn't really happen,
but they do look longer.
One final example of an object
permanence study.
Some of this work's been done
at Yale in Karen Wynn's lab,
where they look at babies'
understanding of addition and
subtraction.
And a lot of it is done with
real objects,
but there's also animated
versions so here is an animated
example.
Babies are surprised.
They expect 2 - 1 = 1 and when
2 - 1 = 2 or 3 or 0,
they look longer,
indicating surprise.
And even six-month-olds are
sensitive to these rudimentary
facts of arithmetic,
telling us something about
their mathematical knowledge,
but also telling us something
about that they expect things to
remain when they're out of
sight.
Now, this research suggests
that infants' understanding of
the physical world is there from
the very start,
but at the same time not
entirely.
We know there are certain
things babies don't know.
Here's an example.
Suppose you show babies this.
You have a block here and then
you have something above there
floating in mid air.
Babies find this surprising.
Even six-month-olds find this
surprising.
It violates gravity,
but six-month-olds aren't smart
enough to know that a block just
stuck over here is also
surprising.
Twelve-month-olds will think
that it should fall.
Six-month-olds don't,
and even 12-month-olds don't
find anything weird about this,
while adults are sophisticated
enough to understand that that's
an unstable configuration and
should fall over.
So, although some things are
built in, some things develop.
And this raises the question
of, "How do we explain
development?"
How do we explain when babies
come to know things that they
didn't originally know?
Well, one answer is neural
maturation, growth of the brain.
Most of the neurons you have
now in your head,
right now, you had when you
were in your mother's uterus.
What happens in development
isn't for the most part the
growth of new neurons.
It's for the most part pruning,
getting rid of neurons.
So, the neural structures
change radically as babies kind
of get rid of excess neurons
through development.
At the same time though,
connections between neurons
grow like crazy and they--and
this process of synaptic growth
where there are the connections
across different synapses peaks
at about two years.
Finally, remember myelination,
where you sort of get this
fatty sheath over your neuron to
make it more effective?
That also happens through
development, and in fact,
it goes through development and
even teenagers are not fully
myelinated.
In particular,
they're not fully myelinated in
their frontal lobes.
Recall that frontal lobes are
involved in things like
restraint and willpower.
And so, it could be the problem
is the baby's brain doesn't
develop yet.
Another possibility is there's
problems with inhibition.
This is related,
again, to the frontal lobes and
this comes out with the A,
not B error.
So, remember the baby reaches,
reaches, reaches.
It's moved, reach,
follow, keeps reaching the same
place.
And it could be that babies
don't know anything about
objects.
But another possibility is once
you do something it's kind of
hard to stop.
It takes a bit of control to
stop.
And there's all sorts of
independent evidence that babies
lack this control.
The part of their brain that
could control certain behaviors
is just not active yet.
There's a very nice
illustration of inhibitory
problems from a "Simpsons"
episode that actually sort of
covers anything you might want
to know about developmental
differences.
And that basically may sum up
much of developmental
psychology.
That the child essentially--he
does A, A, A.
It's moved.
You go, "doh!"
and he keeps going for it.
And there's some evidence
that's true.
Adele Diamond who studies this
finds that although kids reach
for A, they look for B,
as if they know it's there but
they can't stop themselves from
reaching.
And we'll continue this theme a
little bit later.
Finally, it might be kids don't
know things.
Some things you've got to learn.
And this is true in all sorts
of domains – in the social
world, in the economic world,
in the political world – and
it's true as well in the
physical world.
In fact, there's some things
even adults don't know.
So, here's a study by Michael
McCloskey with college students.
Here's the idea.
You have a tube,
a transparent--a tube--a hollow
tube, and at the top of the tube
you throw a ball through so it
whips through the tube and it
comes out.
The question is,
"What happens to it?"
Does it go in the path of A,
or does it go in the path of B?
Without looking around,
who votes for A?
Who votes for B?
Here's the weird thing.
Whenever I do this at Yale
everybody gets the damn thing
right [laughter].
At Johns Hopkins,
50/50, [laughter]
for A and B.
I got to get a better demo.
But anyway, college students
not here, show systematic biases
of incorrect physical
intuitions.
Here's a twist,
and if you found people who
were less wonderful than you
all, and asked them you'd get a
lot of people saying the curving
thing.
But here's a twist.
Ask somebody,
"What if you took a tube and
you squirted water through it?
Where would the water go?"
Nobody chooses B.
Everybody knows the water would
continue in a straight line,
suggesting that when you have
experience that helps you out,
but in absence of experience
you're kind of lost.
We've talked about the physical
world.
What about the social world?
What about the world of people?
Well, there's a lot of research
on this as well.
Babies start off with some
social preferences.
If you take newborn
babies--It's very hard to do
research with newborn babies
actually because of the consent
procedure and everything,
so most of this work is done in
France [laughter],
where they have no laws at all.
They just rush in to--Women
give birth and they rush in and
they say, "We are
psychologists,"
and then we do experiments on
the babies, and it's terrific.
And this is one of them where
they compare babies looking at
this versus this.
Babies like the one that looks
like a face.
These are newborns.
There are some preferences with
humans and with other primates
to favor faces.
Babies are also social animals
too, so they're natural mimics.
Andrew Meltzoff,
for instance,
has found that if you go to a
newborn baby,
and if you find a newborn baby,
this is the first thing you
should do.
Stick your face right up to the
newborn baby and go like this
and stick your tongue out.
And Meltzoff finds that babies
more often than not stick their
tongues out back,
suggesting some sort of social
connection from one person to
another, and then later on
babies are mimics.
Babies more often than not will
copy the face next to them.
Now, these--the nature of these
responses, this preferring
faces, this sort of mimicry,
is a matter of debate,
and there's a lot of research
going on asking how smart are
babies.
Can we see--use some of the
same methods that we've looked
at for the physical world to
look at the social world?
And to illustrate one of the
studies, I'll tell you about a
study that I did with Valerie
Kuhlmeier and Karen Wynn.
And so, what we tested was
nine-month-olds and
twelve-month-olds,
and we showed them movies.
So, they're sitting down and
they're seeing a movie where one
character's going to help a ball
achieve a goal,
and another character's going
to hinder the ball.
And then we're going to see
whether they expect the ball to
approach the one that helped it
versus the one that hindered it.
So, this is what a baby would
see.
This is literally the same
movie a baby would see in the
experiment.
The thing is for these sorts of
experiments there is a lot of
control, so something that's a
square in one movie will be a
triangle in another movie;
something that's on the top in
one movie will be on the bottom
in another movie.
So, this is an example movie
but this is what babies would
see.
And they'd see this over and
over again and the question is
would they expect babies--would
babies expect the one to
approach the one that helped it
or approach the one that
hindered it?
And what we find is,
statistically,
babies look longer when shown a
movie where it approaches the
one that hindered it versus
helped it.
And this we take as preliminary
evidence that they have a social
interpretation.
They see this movie as you see
this movie in terms of helping
and hindering,
and somebody going to somebody
that helped it versus hindered
it.
You could then ask--This makes
a prediction that babies should
themselves prefer the creature
who's the helper versus the
hinderer,
and to explore this,
a graduate student in this
department, Kiley Hamlin,
has started a series of studies
where they show babies
three-dimensional scenes and
then give them the characters
and see which one they reach
for.
So, here's video so you could
see how this experiment is done.
Now, the next trial is from a
different study.
A different thing we use,
and the baby is given a choice.
One thing to know
methodologically is the person
giving a choice is blind to the
study.
And blind here is a technical
term meaning she had no idea
what the baby saw,
and the point about this is to
avoid either intentional or
unintentional sort of trying to
get the answer you want.
She couldn't do that because
she didn't know what the right
answer is.
So, here's what the baby would
see.
So, this suggests that some
social understanding may be
there from the very start.
This evidence is tentative,
very controversial.
But now, I want to raise a huge
developmental puzzle and the
puzzle is there are some ways in
which babies are--not just
babies,
but young children are very
clueless when it comes to
people.
And so, I have a film clip here
of two very nice studies showing
babies' ignorant--sorry,
young children's ignorance of
other people.
I'll show you the studies and
then we'll briefly discuss what
they mean.
Professor Paul Bloom:
Before discussing that example
in a little bit more detail,
any questions?
What are your questions?
Yes, in back.
Student: [inaudible]
Professor Paul Bloom:
Typically--I don't know for
those particular children,
but typically on those tasks
three-year-olds and young
four-year-olds tend to fail,
and around the age of four or
five kids tend to succeed.
There's sort of a period around
the age of four,
four and a half,
where kids make the transition
from failure to success.
The question,
by the way, was when do
children--in that video when
were the--what were the ages of
the children who failed and who
passed?
Yes.
Student: [inaudible]
Professor Paul Bloom:
The question of whether
discriminant conditioning has
been used with babies to explore
what sort of concepts they have.
I don't know.
Does anybody--It has been--
Graduate Student:
--It's not as effective--
Professor Paul Bloom:
Koleen answered and said that
it's not as effective as other
methods.
Part of the problem with using
operant conditioning with babies
is it's difficult to get them to
behave in any systematic way.
So, the looking-time measures
tend to be more subtle.
Any other questions?
Oh.
Yes.
Student: [inaudible]
Professor Paul Bloom:
Oh.
The question of why they
chose--the baby--the kids chose
the rocket ship one as opposed
to the Rafael one.
It wasn't what they were
interested in in the experiment.
And my bet is when they chose
the stickers they had a pretty
good sense of why,
of which ones the boys would
prefer in those studies.
The question of why a boy might
prefer one sort of sticker,
and you might get a different
response with a girl,
is going to come up later when
we discuss different theories of
sex differences.
But that was something I think
they were just assuming in the
study to get it off the ground.
Okay.
There's a huge debate over
what's going on there.
And if you listened at the end
to the psychologist summarizing
the data, the psychologist had a
very good and very clear and
strong idea of what was going
on.
It was that children need to
know more about minds.
The children don't know about
that you can do something with
the intent to deceive.
They don't understand that
somebody could choose what you
chose in a malicious way.
This is possible.
This is one respectable theory,
but the alternative is they
have the right knowledge,
but they suffer from problems
with inhibition.
So, consider both studies.
The first study,
the one with the deceptive
dolls with the big shoes and
little shoes,
is actually fairly difficult.
And it's possible that children
kind of got overwhelmed with it,
and when asked what would the
mother think,
who the mother would think
stole the food,
responded with who really stole
the food.
And that there's some pull
towards the right answer that
makes this task difficult.
The second one--the second
study illustrates this issue
even more clearly.
Take the boy who kept failing.
He kept pointing to the rocket
ship and mean monkey kept taking
it away.
It's possible that he genuinely
didn't know what to do,
that he wasn't smart enough to
understand that he needed to
point to the other one.
But it's also possible that
it's a Homer Simpson-like
effect, where when asked to
point to what he wants,
he just couldn't help but point
to the one he wanted.
And that the extra work it
takes to lie was beyond him.
And, in support of the second
alternative, even adults find
these tasks involving lying and
deception more difficult.
They were slower at them.
We make more mistakes than
tasks that don't involve lying
and deception.
So, I'm raising this not to
solve the problem.
You'll read more about it in
the Peter Gray textbook and more
about it in The Norton
readings on development,
but just to raise this as an
interesting area of debate.
Another interesting area of
debate is, "What's the
relationship between different
sorts of development?"
So, I started off with Piaget,
and Piaget, like Freud,
believed in general,
across the board changes in how
children think.
An alternative,
though, is that there's
separate modules,
and this is a view developed,
again, by Noam Chomsky,
and also by the philosopher of
mind Jerry Fodor,
who claimed that the whole idea
of a child developing as a
single story is mistaken.
What you get instead is there
are separate pre-wired systems
for reasoning about the world.
These systems have some
built-in knowledge,
and they have to do some
learning,
but the learning pattern varies
from system to system and
there's a separateness to them.
Why should we take this view
seriously?
Well, one reason is that there
are developmental disorders that
seem to involve damage to one
system but not to another.
And the classic case of this is
a disorder known as autism.
And autism is something I've
always found a fascinating
disorder for many reasons.
It's actually why I entered
psychology.
I started off working with
children with autism.
And it could be taken as a
striking illustration of how the
social part of your brain is
distinct from other parts of
your brain.
So, what autism is is a
disorder that strikes about one
in a thousand people,
mostly boys.
And the dominant problems
concern--consist of a lack of
social connectedness,
problems with language,
problems dealing with people,
and more generally,
a problem of what the
psychologist,
Simon Baron-Cohen has described
as "mind blindness."
In that autistic people show no
impairments dealing with the
physical world,
they show no impairments
on--they don't necessarily show
any impairments on mathematical
skills or spatial skills,
but they have a lot of problems
with people.
Now, many autistic children
have no language;
they're totally shut off from
society.
But even some of them who'd
learned language and who managed
to get some sort of independent
life,
nevertheless will suffer from a
severe social impairment.
And this could be shown in all
sorts of ways.
A simple experiment developed
by Simon Baron-Cohen goes like
this.
You show this to three- and
four-year-olds.
There's four candies there,
and you say,
"This is Charlie in the middle.
Which chocolate will Charlie
take?"
For most children and most of
you, I hope, the answer's pretty
clear: This one.
Autistic children will often
just shrug, say,
"How could I know?"
because they don't
instinctively appreciate that
people's interests and desires
tend to be attuned to where
they're looking.
Another sort of task,
which is a task that's been
done hundreds,
perhaps thousands of times,
is known as "the false-belief
task" and here's the idea.
You show the child the
following situation.
There's a doll named Maxie and
Maxie puts the ball in the
cupboard.
Maxie leaves and a second doll
enters.
The second doll takes the ball
out of the cupboard and puts it
under the bed.
Maxie comes back and the
question is, "Where will Maxie
look for the ball?"
Now, this is a question about
your understanding about minds.
The question of where is the
ball really is a question about
the physical world.
Everyone can solve it,
but this question is hard.
The right answer is Max
will--Maxie will look in the
cupboard, even though it's not
really there because Maxie has a
false belief about the world.
Three-year-olds find this
difficult.
Two-year-olds find this
difficult.
Four-year-olds and
five-year-olds are able to pass
this task.
Normal adults are able to pass
this task.
Children with autism have
serious problems.
And often, people with autism
who are otherwise very high
functioning will fail this task.
They'll say,
"Oh, he must think it's
not--He'll--He's going to check
under the bed."
Any questions about autism?
Yes.
Student: [inaudible]
Professor Paul Bloom:
Good question.
It isn't.
They're both experiments
designed to tap an appreciation
of false belief.
The deception one with the
shoes and everything looked at
it in the course of deception.
Can you understand that the
mother might think it's that
person even though it's really
that person?
And our kid failed.
This is a sort of stripped-down
version without all the
fanciness but it tests exactly
the same thing.
Yes.
Student: [inaudible]
Professor Paul Bloom:
Nobody knows,
but there's a theory which
won't answer your question but
will put it into a broader
context.
Simon Baron-Cohen argues that
there are certain abilities that
tend to be more sequestered for
males,
and other abilities that are
more sequestered,
more focused on females.
Social abilities,
he argues, tend to be more
female than male.
So, the way Baron puts it,
provocatively,
is to be a man is to suffer
from a very mild form of autism
[laughter].
The idea is then that autistic
individuals suffer from what he
calls extreme male brains,
and as such,
it stands to reason that they'd
be more sampled from the male
population than the female
population.
That's such an interesting
issue, that again,
when we return to talk about
sex differences we'll look at
that in a little bit more detail
to see if it's supported by the
evidence.
Yes.
Student: [inaudible]
Professor Paul Bloom:
I'm sorry.
Tell me the--Is the severity of
autism… Student:
[inaudible]
Professor Paul Bloom:
It's an interesting question.
The question is,
"How do you think about the
severity of autism with regard
to developmental stages?"
And sort of surprisingly,
autism can't really be thought
of in that way.
So, it's not like an adult with
autism is like a three-year-old
or a two-year-old.
In some ways,
somebody with autism isn't like
any child at all,
any normally developing child
at all.
So, it's not really a
developmental delay in the way
that it might make sense to
think about certain forms of
retardation.
On the other hand,
when we think about how severe
autism is we do look at things
like how much language does the
person have,
and in that sense,
it is related to development.
Yes.
Student:
What are the chances that
someone who's autistic would be
able to overcome their
deficiencies?
Professor Paul Bloom:
The majority of people with
autism.
It's a good question.
The question is,
"What are the chances that
somebody with autism will be
able to overcome their
deficiencies?"
Autism is a funny disorder in
that there's a lot of media
publication and media
presentation.
Often the people who are
showcased in the media tend to
be very exceptional.
So, there's a woman,
Temple Grandin,
who's autistic and--Has anybody
here heard of Temple Grandin?
She wrote some wonderful books
about her experience as an
autistic person,
but she's very unusual.
So a lot depends,
to answer your question,
how one defines autism,
and whether one includes
Asperger syndrome,
which is a limited,
a more mild syndrome,
as a form of autism.
The answer is that the majority
of people with autism have
severe problems,
and will not,
and at this stage,
with this level of therapy,
will not lead a normal life.
Student:
More specifically,
what I meant was,
when you showed the example of
Rain Man, ere they exceptional
[inaudible]
Professor Paul Bloom:
Right.
The question is about so-called
autistic savants.
So, Rain Man,
the character played by Dustin
Hoffman, had extraordinary
mathematical abilities.
And some people with autism
have extraordinary artistic
abilities or mathematical
abilities or musical abilities
and these are amazing.
It's an amazing question why
they have it but this is a very
small minority.
This is a very--It's
fascinating that it happens at
all, that you have severe damage
but compensated with some
powerful skill.
Now, I know I'm answering your
question I think in a better
way, but it's actually very
rare.
Most people with autism do not
have any exceptional abilities
that go along with it.
Another question is if you
believe in modules--If there are
modules, what are they?
And so far when reviewing the
developmental data we've talked
about two of them:
physics and people.
An object module and a social
module.
But other people have argued
that there is a special module
in your brain for dealing with
artifacts,
that is, things like tables and
chairs and cars and forks.
Some people have argued there's
a module for sociology,
for dealing with human groups,
races and classes and so on.
Some have even argued that
there is an intuitive biology,
a common-sense biological
understanding of the world
that's separate from your
understanding of people and
physics.
And, in fact,
the most dominant proponent of
the view is our very own Frank
Keil,
Master of Morse College at
Yale, who has strongly defended
the notion of an intuitive
biological module.
Final question,
just to raise:
I've talked in terms of the
modular view but there might
also be profound general
differences between children and
adults,
not just specific to how you
think about objects or how you
think about people or how you
think about this or how you
think about that,
but rather more general.
And one claim,
which we're going to return to
briefly next class when we talk
about language,
is that there's a very,
very big difference between a
creature that doesn't have
language and a creature that
does.
And part of the claim is that
learning a language,
learning to speak,
reconfigures the human brain in
such a way that is really
exceptional.
And that has no parallel in any
other species.
And this is an interesting
claim and one we'll talk about.
Finally, I want to end with an
example from Stephen Jay Gould.
Suppose you hate development;
you hate developmental
psychology;
you hate babies;
you hate children;
they're not cute;
they're ugly;
you don't want to have them;
you don't want to study them;
you're annoyed that we have to
discuss them.
Fine.
But there are reasons to study
development even if you are not
interested in children because
sometimes developmental studies
and developmental data and
developmental science can inform
questions about adults.
And Stephen Jay Gould has a
very nice example of this.
He asked the question "Is a
zebra a black animal with white
stripes or a white animal with
black stripes?"
Now, you could look at adult
zebras all day long and you're
never going to figure this out.
But if you want to know the
answer, and I knew it,
but I forget what it is--It
doesn't matter.
But if you wanted to know it
you could.
You would look at development
and you'd watch the
embryological development of a
zebra and that's how you would
learn the answer to your
question.
In fact, I'll end with a nice
quote.
This is by the famous
biologist, D'Arcy Thompson,
who wrote the book On Growth
and Form,
and it's sort of the model
of many developmental
psychologists and many
evolutionary psychologists so
I'll end with this:
"Everything is the way it is
because it got that way."
Okay.
I'll see you next week.