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