What do babies think Alison Gopnik

what is going on in this baby’s mind if

you’d ask people this thirty years ago

most people including psychologists

would have said that this baby was

irrational illogical egocentric that he

couldn’t take the perspective of another

person or understand cause and effect in

the last 20 years developmental science

has completely overturned that picture

so in some ways we think that this

baby’s thinking is like the sinking of

the most brilliant scientists let me

give you just one example of this one

thing that this baby could be thinking

about that could be going on in his mind

is trying to figure out what’s going on

in the mind of that other baby after all

one of the things that’s hardest for all

of us to do is to figure out what other

people are thinking and feeling and

maybe the hardest thing of all is to

figure out that what other people think

and feel isn’t actually exactly like

what we think and feel anyone who’s

followed politics can testify to how

hard that is for some people to get we

wanted to know if babies and young

children could understand this really

profound thing about other people now

the question is how could we ask them

babies after all can’t talk and if you

ask a three-year-old to tell you what he

thinks what you’ll get is a beautiful

stream of consciousness monologue eBay

ponies and birthdays and things like

that so how could we actually ask them

the question well it turns out that the

secret was broccoli what we did

Betty Rebecca Lee was one of my students

and I was actually to give the babies

two bowls of food one bowl of raw

broccoli and one bowl of delicious

goldfish crackers now all of the babies

even in Berkeley like the crackers and

Jones like the raw broccoli

but then what they did was to take a

little taste of food from each Bowl and

she would act as if she liked it or she

didn’t so half the time she acted as if

she liked the crackers and didn’t like

the broccoli just like the baby and any

other same person but half a time what

you would do is take a little bit of the

broccoli and go mmm

broccoli I tasted the broccoli hmm and

then she would take a little bit of the

crackers and she’d go oh yeah crackers I

tasted the crackers oh yeah so she act

as if what she wanted was just the

opposite of what the babies want it we

did this with fifteen and eighteen month

old babies and then she would simply put

her hand out and say can you give me

some so the question is what would the

baby giver what they liked or what she

liked and the remarkable thing was that

eighteen month old babies just barely

walking and talking would give her the

crackers if she liked the crackers but

they would give her the broccoli if she

liked the broccoli on the other hand

fifteen month olds would stare at her

for a long time if she acted as if she

liked the broccoli like they couldn’t

figure this out

but then after they stared for a long

time they would just give her the crack

that’s what they thought everybody must

like so there are two really remarkable

things about this the first one is that

these little 18 month old babies have

already discovered this really profound

fact about human nature that we don’t

always want the same thing and once more

they felt that they should actually do

things to help other people get what

they wanted even more remarkably though

the fact that the 15 month olds didn’t

do this suggests that these 18 month

olds had learned this deep profound fact

about human nature in the three months

from the time they were 15 months old so

children both know more and learn more

than we ever would have thought and this

is just one of hundreds and hundreds of

studies over the last twenty years

that’s actually demonstrated this the

question you might ask though is why do

children learn so much and how is it

possible for them to learn so much in

such a short time I mean after all if

you look at babies superficially they

seem pretty useless and actually in many

ways they’re worse than you

because we have to put so much time and

energy into just keeping them alive but

if we turn to evolution for an answer to

this puzzle of why we spend so much time

taking care of useless babies it turns

out that there’s actually an answer if

we look across many many different

species of animals not just us primates

but also including other mammals birds

even marsupials like kangaroos and

wombats it turns out that there’s a

relationship between how long a

childhood and a species has and how big

their brains are compared to their

bodies and how smart and flexible they

are and sort of the poster birds for

this idea are the birds up there on one

side is a New Caledonian crow and crows

and other corvids Raven Brooks and so

forth are incredibly smart birds they’re

as smart as chimpanzees in some respects

and this is a bird on the cover of

science who’s learned how to use a tool

to get food on the other hand we have

our friend the domestic chin and

chickens and ducks and geese and turkeys

are basically as dumb as stumps so

they’re very very good at pecking for

grain and they’re not much good at doing

anything else well it turns out that the

babies that New Caledonian crow babies

are fledglings they depend on their moms

to drop worms in their little open

mouths for as long as two years which is

a really long time in the life of a bird

whereas the chickens are actually mature

within a couple of months so childhood

is the reason why the crows end up on

the cover of science and the chickens

end up in the soup pot there’s something

about that long childhood that seems to

be connected to knowledge and learning

well what kind of explanation could we

have for this well some animals like the

chicken seem to be beautifully suited to

doing just one thing very well so they

seem to be beautifully suited to packing

grain in one environment other creatures

like the crows aren’t very good at doing

anything in particular but they’re

extremely good at learning about lots of

different environments and of course we

human beings are way out on the end of

the distribution like the crows

we have bigger brains relative to our

bodies by far than any other animal

we’re smarter we’re more flexible we can

learn more we survive in more different

environments we’ve migrated to cover the

world and even go to outer space and our

babies and children are dependent on us

for much longer than the babies of any

other species

my son is 23 and at least until they’re

23 we’re still popping those worms into

those little open mouths all right why

would we see this correlation well an

idea is that that strategy that learning

strategy is an extremely powerful great

strategy for getting on in the world but

it has one big disadvantage and that one

big disadvantage is that until you

actually do all that learning you’re

going to be helpless so you don’t want

to have the mastodon charging at you and

be saying to yourself a slingshot or

maybe a spear might work which would

actually be better you want to know all

that before the mastodons actually show

up and the way that evolution seems to

have solved that problem is with a kind

of division of labor so the idea is that

we have this early period when we’re

completely protected we don’t have to do

anything all we have to do is learn and

then as adults we can take all those

things that we learned when we were

babies and children actually put them to

work to do things out there in the world

so one way of thinking about it is that

babies and young children are like the

research and development division of the

human species so they’re the protected

blue sky guys who just have to go out

and learn and have good ideas and we’re

production and marketing we have to take

all those ideas that we learned when we

were children and actually put them to

use another way of thinking about it is

instead of thinking about babies and

children as being like defective

grown-ups we should think about them as

being a different developmental stage of

the same species kind of like

caterpillars and butterflies except that

they’re actually the brilliant

butterflies who are flitting around the

garden and exploring and we’re that

caterpillars who are inching along our

narrow grown-up adult path if this is

true if these babies are designed to

learn and this evolutionary story would

say children are for learning that’s

what they’re for we might expect

that they would have really powerful

learning mechanisms and in fact the

baby’s brain seems to be the most

powerful learning computer on the planet

but real computers are actually getting

to be a lot better and there’s been a

revolution in our understanding of

machine learning recently and it all

depends on the ideas of this guy the

Reverend Thomas Bayes who was a

statistician and mathematician in the

18th century

and essentially what Bayes did was to

provide a mathematical way using

probability theory to characterize to

describe the way that scientists find

out about the world so what scientists

do is they have a hypothesis that they

think might be likely to start with they

go out and test it against the evidence

the evidence makes them change that

hypothesis then they test that new

hypothesis and so on and so forth and

what Bayes showed was a mathematical way

that you could do that and that

mathematics is at the core of the best

machine learning programs that we have

now and some 10 years ago I suggested

that babies might be doing the same

thing so if you want to know what’s

going on underneath those beautiful

brown eyes I think it actually looks

something like this this is Reverend

bayes’s notebook so I think those babies

are actually making complicated

calculations with conditional

probabilities that they’re revising to

figure out how the world works all right

now that might seem like an even taller

order to actually demonstrate because

after all if you ask even grown-ups

about statistics they look extremely

stupid how could it be that children are

doing statistics so to test this we used

a machine that we have called the

blicket detector this is a box that

lights up and plays music when you put

some things on it and not others and

using this very simple machine my lab

and others have done dozens of studies

showing just how good babies are at

learning about the world let me just

mention just one that we did with

tomorrow Kushner my student if I showed

you this detector you would be likely to

think to begin with that the way to make

the detector go would be to put a block

on top of the detector but actually this

detector works in a bit of a strange way

because if you wave a block over the top

of the detector something you wouldn’t

ever think of to begin with the detector

will actually activate 2 out of 3 times

whereas if you do the likely thing

the block all of the detector it will

only activate two out of six times so

the unlikely hypothesis actually has

stronger evidence it looks as if the

waving is a more effective strategy than

the other strategy so we did just this

we gave four-year-olds this pattern of

evidence and we just asked them to make

it go and sure enough the four-year-olds

use the evidence to wave the object on

top of the detector now there are two

things that are really interesting about

this the first one is again remember

these are four-year-olds they’re just

learning how to count but unconsciously

they’re doing these quite complicated

calculations that will give them a

conditional probability measure and the

other interesting thing is that they’re

using that evidence to get you an idea

yet to a hypothesis about the world that

seems very unlikely to begin with and in

studies we’ve just been doing in my lab

similar studies we’ve shown that

four-year-olds are actually better at

finding out an unlikely hypothesis than

adults are when we give them exactly the

same task so in these circumstances the

children are using statistics to find

out about the world but after all

scientists also do experiments and we

wanted to see if children are doing

experiments when children do experiments

we call it getting into everything or

else playing and there’s been a bunch of

interesting experiments of studies

recently that have shown that this

playing around is really a kind of

experimental research program

here’s one from Christine Lagarde’s lab

what Christine did was use our liggett

detectors and what she did was show

children that yellow ones made it go and

red ones didn’t and then she showed them

uh nanami and what you’ll see is that

this little boy will go through five

hypotheses in the space of two minutes

okay so he just his first hypothesis has

just been falsified

this one played out in this wooden oh

okay he’s got his experimental notebook

out every scientist will recognize that

expression of despair right oh this

would be like their okay hypothesis -

now this is his next idea

he totally experiments Judas to try

putting it out over on to the other

location not working on them you know

Oh

because blight goes only to here not few

oh the bottom of this box has

electricity in here but this doesn’t

have electricity

okay that’s a fourth hypothesis yeah I

mean you don’t need what for on this one

to make it light up and do on this one

okay there’s a fifth hypothesis now that

is particularly that is a particularly

adorable and articulate little boy but

what Christine discovered is this is

actually quite typical if you look at

the way children play when you ask them

to explain something what they really do

is do a series of experiments this is

actually pretty typical of

four-year-olds well what’s it like to be

this kind of creature what’s it like to

be one of these brilliant butterflies

who can test five hypotheses in two

minutes well if you go back to their

psychologists and philosophers a lot of

them had said that babies and young

children were barely conscious if they

were conscious at all

and I think just the opposite is true I

think babies and children are actually

more conscious than we are as adults now

here’s what we know about how adult

consciousness works and adults attention

and consciousness look kind of like a

spotlight so what happens for adults is

we decide that something’s relevant or

important we should pay attention to it

our consciousness of that thing that

we’re attending to becomes extremely

bright and vivid and everything else

sort of goes dark and we even know

something about the brain the way the

brain does this so what happens when we

pay attention is that the prefrontal

cortex the sort of executive part of our

brain sends a signal that makes a little

part of our brain much more flexible

more plastic better at learning and

shuts down activity in all the rest of

our brains so we have a very focused

purpose driven kind of attention if we

look at babies and young children we see

something very different

I think babies and young children seem

to have more of a lantern of

consciousness than a spotlight of

consciousness so babies and young

children are very bad at narrowing down

to just one thing but they’re very good

at taking in lots of information from

lots of different sources at once and if

you actually look in their brains you

see that they’re flooded with these

neurotransmitters that are really good

inducing learning and plasticity and the

inhibitory parts haven’t come on right

yet so when we say that babies and young

children are bad at paying attention

what we really mean is that they’re bad

at not paying attention so they’re bad

at getting rid of all the interesting

things that could tell them something

and just looking at the thing that’s

important that’s the kind

attention the kind of consciousness that

we might expect from those butterflies

who are designed to learn well if we

want to think about a way of getting a

taste of that kind of baby consciousness

as adults I think the best thing is

think about cases where we’re put in a

new situation that we’ve never been in

before when we fall in love with someone

new or when we’re in a new city for the

first time and what happens then is not

that our consciousness contracts it

expands so that those three days and

power-ups seem to be more full of

consciousness and experience than all

the months of being a walking talking

faculty meeting attending zombie back

home and by the way that coffee that

wonderful coffee you’ve been drinking

downstairs actually mimics the effect of

those baby neurotransmitters so what’s

it like to be a baby it’s like being in

love in Paris for the first time after

you’ve had three double espresso which

is that’s a fantastic way to be but it

does tend to leave you waking up crying

at 3 o’clock in the morning now it’s

good to be a grown-up I don’t want to

take too much about how wonderful babies

are it’s good to be a grown-up we can do

things like tie our shoelaces and cross

the street by ourselves and it makes

sense that we put a lot of effort into

actually making babies think like adults

do but if what we want is to be like

those butterflies to have open

mindedness open learning imagination

creativity innovation maybe at least

some of the time we should be getting

the adults to start thinking more like

children

you