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