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