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