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