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