What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would said that this baby was irrational, illogical, egocentric — he couldn’t take the perspective of another person or understand and effect. In the last 20 years, developmental science has completely overturned that picture. So in some ways, think that this baby’s thinking is like the thinking the most brilliant scientists.
Let me give you just one example of this. thing that this baby could be thinking about, that be going on in his mind, is trying to figure what’s going on in the mind of that other baby. After all, one of the things that’s for all of us to do is to figure what other people are thinking and feeling. And maybe the hardest thing all is to figure out that what other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can testify to how that is for some people to get. We wanted know if babies and young children could understand this really profound thing about other people. Now question is: How could we ask them? Babies, after all, can’t talk, and you ask a three year-old to tell you what he thinks, you’ll get is a beautiful stream of consciousness monologue about ponies and birthdays and things like that. how do we actually ask them the question?
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Well it turns that the secret was broccoli. What we did — Betty Rapacholi, who was one of my students, and — was actually to give the babies two bowls of food: one bowl of raw broccoli one bowl of delicious goldfish crackers. Now all of babies, even in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take a little taste food from each bowl. And she would act as if she liked it or she didn’t. So the time, she acted as if she liked the crackers and didn’t like the — just like a baby and any other sane person. But half the time, what would do is take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted broccoli. Mmmmm.” And then she would take a little bit of crackers, and she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d act if what she wanted was just the opposite of what the babies wanted. We this with 15 and 18 month-old babies. And then she would simply put her hand out say, “Can you give me some?”
So the question is: What would the baby give her, what they liked what she liked? And the remarkable thing was that 18 month-old babies, just barely walking talking, would give her the crackers if she liked the crackers, but they would give her the broccoli she liked the broccoli. On the other hand, 15 month-olds would stare at her for a long time if acted as if she liked the broccoli, like they couldn’t figure this out. But then after they for a long time, they would just give her crackers, what they thought everybody must like. So there are two really things about this. The first one is that these 18 month-old babies have already discovered this really profound fact about nature, that we don’t always want the same thing. what’s more, they felt that they should actually do things to help other people get they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t do this suggests that these 18 month-olds had learned deep, profound fact about human nature in the three months when they were 15 months old. So children both know and learn more than we ever would have thought. this is just one of hundreds and hundreds of studies over last 20 years that’s actually demonstrated it.
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The question you ask though is: Why do children learn so much? And how is it possible for to learn so much in such a short time? I mean, after all, if you at babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to put so much time and energy just keeping them alive. But if we turn to evolution for an to this puzzle of why we spend so much taking care of useless babies, it turns out that there’s actually an answer. we look across many, many different species of animals, just us primates, but also including other mammals, birds, marsupials like kangaroos and wombats, it turns out that there’s a relationship between how long a a species has and how big their brains are compared to their bodies and how and flexible they are.
And sort of the posterbirds for this are the birds up there. On one side is a Caledonian crow. And crows and other corvidae, ravens, rooks and so forth, are smart birds. They’re as smart as chimpanzees in some respects. this is a bird on the cover of science who’s how to use a tool to get food. On the hand, we have our friend the domestic chicken. And chickens ducks and geese and turkeys are basically as dumb as dumps. they’re very, very good at pecking for grain, and they’re not good at doing anything else. Well it turns out that the babies, the New crow babies, are fledglings. They depend on their moms to drop worms in their little open mouths for long as two years, which is a really long time in the of a bird. Whereas the chickens are actually mature within a couple of months. So is the reason why the crows end up on the of Science and the chickens end up in the soup pot.
There’s something about that childhood that seems to be connected to knowledge and learning. Well what kind of explanation we have for this? Well some animals, like the chicken, seem be beautifully suited to doing just one thing very well. they seem to be beautifully suited to pecking grain one environment. Other creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about laws of different environments.
And of course, we human are way out on the end of the distribution like the crows. We have bigger relative to our bodies by far than any other animal. We’re smarter, we’re more flexible, we learn more, we survive in more different environments, we migrated to cover the world and even to outer space. And our babies and children are dependent us for much longer than the babies of any other species. My is 23. (Laughter) And at least until they’re 23, we’re still popping those worms into those little mouths.
All right, why would we see this correlation? Well an idea is that that strategy, learning strategy, is an extremely powerful, great strategy for getting in the world, but it has one big disadvantage. that one big disadvantage is that, until you actually all that learning, you’re going to be helpless. So don’t want to have the mastodon charging at you and be saying to yourself, “A or maybe a spear might work. Which would actually be better?” want to know all that before the mastodons actually show up. And way the evolutions seems to have solved that problem is with a kind division of labor. So the idea is that we have this early period when we’re protected. We don’t have to do anything. All we have to do is learn. And then adults, we can take all those things that we learned when we were babies children and actually put them to work to do things out there the world.
So one way of thinking about it is that and young children are like the research and development of the human species. So they’re the protected blue sky guys who just to go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas that we learned when we were and actually put them to use. Another way of about it is instead of thinking of babies and children as being like defective grownups, we should think them as being a different developmental stage of the same species — kind of like and butterflies — except that they’re actually the brilliant who are flitting around the garden and exploring, and we’re caterpillars who are inching along our narrow, grownup, adult path.
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If this is true, if babies are designed to learn — and this evolutionary would say children are for learning, that’s what they’re for — might expect that they would have really powerful learning mechanisms. And fact, the baby’s brain seems to be the most learning computer on the planet. But real computers are actually getting be a lot better. And there’s been a revolution in our of machine learning recently. And it all depends on the of this guy, the Reverend Thomas Bayes, who was statistician and mathematician in the 18th century. And essentially Bayes did was to provide a mathematical way using probability theory to characterize, describe, the way that find out about the world. So what scientists do is have a hypothesis that they think might be likely to start with. They go and test it against the evidence. The evidence makes them change that hypothesis. Then test that new hypothesis and so on and so forth. And what Bayes showed was a way that you could do that. And that mathematics at the core of the best machine learning programs that have now. And some 10 years ago, I suggested that babies might be doing same thing.
So if you want to know what’s going on underneath those beautiful eyes, I think it actually looks something like this. This Reverend Bayes’s notebook. So I think those babies are actually making calculations with conditional probabilities that they’re revising to figure how the world works. All right, now that might seem like an even order to actually demonstrate. Because after all, if you ask even grownups about statistics, they extremely stupid. How could it be that children are doing statistics?
So to this we used a machine that we have called Blicket Detector. This is a box that lights up and plays music when you some things on it and not others. And using this simple machine, my lab and others have done dozens of showing just how good babies are at learning about the world. me mention just one that we did with Tumar Kushner, student. If I showed you this detector, you would be to think to begin with that the way to make detector go would be to put a block on of the detector. But actually, this detector works in a bit of a strange way. if you wave a block over the top of detector, something you wouldn’t ever think of to begin with, the will actually activate two out of three times. Whereas, if you the likely thing, put the block on the detector, it will only activate two of six times. So the unlikely hypothesis actually has stronger evidence. It looks if the waving is a more effective strategy than other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked them to it go. And sure enough, the four year-olds used the to wave the object on top of the detector.
Now are two things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning how to count. But unconsciously, they’re these quite complicated calculations that will give them a conditional probability measure. the other interesting thing is that they’re using that evidence to get an idea, get to a hypothesis about the world, that very unlikely to begin with. And in studies we’ve just been doing my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, children are using statistics to find out about the world, after all, scientists also do experiments, and we wanted to see if are doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of interesting studies recently that have shown this around is really a kind of experimental research program. Here’s from Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. what she did was show children that yellow ones made it go red ones didn’t, and then she showed them an anomaly. what you’ll see is that this little boy will go through hypotheses in the space of two minutes.
(Video) Boy: How this? Same as the other side.
Alison Gopnik: Okay, so first hypothesis has just been falsified.
(Laughter)
Boy: This lighted up, and this one nothing.
AG: Okay, he’s got his notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every scientist will recognize expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to be this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told experimenter to do this, to try putting it out onto the other location. Not working either.
Boy: Oh, the light goes only to here, not here. Oh, the bottom of this box has electricity here, but this doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s up. So when you put four. So you put four this one to make it light up and two on this one to make it up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, what Cristine discovered is this is actually quite typical. If you look at way children play, when you ask them to explain something, what really do is do a series of experiments. This actually pretty typical of four year-olds.
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Well, what’s it like be this kind of creature? What’s it like to one of these brilliant butterflies who can test five hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have said that and young children were barely conscious if they were conscious at all. And I think just the opposite true. I think babies and children are actually more conscious we are as adults. Now here’s what we know about how adult works. And adults’ attention and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant or important, we should pay attention to it. Our of that thing that we’re attending to becomes extremely bright and vivid, and everything else sort goes dark. And we even know something about the the brain does this.
So what happens when we pay is that the prefrontal cortex, the sort of executive part of our brains, sends a signal makes a little part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven of attention. If we look at babies and young children, we see something very different. I think babies and children seem to have more of a lantern of than a spotlight of consciousness. So babies and young children are very bad at narrowing down to one thing. But they’re very good at taking in of information from lots of different sources at once. And if actually look in their brains, you see that they’re with these neurotransmitters that are really good at inducing and plasticity, and the inhibitory parts haven’t come on yet. So when we say that and young children are bad at paying attention, what we really mean is that they’re bad at paying attention. So they’re bad at getting rid of all the interesting that could tell them something and just looking at the that’s important. That’s the kind of attention, the kind of consciousness, that we might expect from those butterflies are designed to learn.
Well if we want to about a way of getting a taste of that kind of baby consciousness as adults, think the best thing is think about cases where we’re put in a new situation that we’ve never been before — when we fall in love with someone new, or when we’re in new city for the first time. And what happens then is that our consciousness contracts, it expands, so that those three days Paris seem to be more full of consciousness and than all the months of being a walking, talking, meeting-attending zombie back home. And by the way, that coffee, that wonderful you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it like to be baby? It’s like being in love in Paris for the first after you’ve had three double-espressos. (Laughter) That’s a fantastic to be, but it does tend to leave you waking up crying at o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want to say too about how wonderful babies are. It’s good to be grownup. We can do things like tie our shoelaces and cross the by ourselves. And it makes sense that we put a of effort into making babies think like adults do. But if what we want is to be like butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe least some of the time we should be getting the adults to start more like children.
(Applause)