What is on in this baby’s mind? If you’d asked people 30 years ago, most people, including psychologists, would have said that this baby irrational, illogical, egocentric — that he couldn’t take the perspective of person or understand cause 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 brilliant scientists.
Let me give you just one example of this. thing that this baby could be thinking about, that be going on in his mind, is trying to figure out what’s going on in the mind that other baby. After all, one of the things that’s for all of us to do is to figure what other people are thinking and feeling. And maybe the hardest thing of is to figure out that what other people think and feel isn’t actually like what we think and feel. Anyone who’s followed politics can testify to hard that is for some people to get. We 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 a year-old to tell you what he thinks, what you’ll get a beautiful stream of consciousness monologue about ponies and birthdays and like that. So how do we actually ask them the question?
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Well turns out that the secret was broccoli. What we did — Betty Rapacholi, who was one of students, and I — was actually to give the babies two bowls of food: one bowl raw broccoli and one bowl of delicious goldfish crackers. Now all of the babies, even in Berkley, the crackers and don’t like the raw broccoli. (Laughter) But what Betty did was to take a little taste of food from each bowl. And she would as if she liked it or she didn’t. So half the time, she as if she liked the crackers and didn’t like the broccoli — just like a baby and other sane person. But half the time, what she would do is take a little 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 just the opposite of the babies wanted. We did this with 15 and 18 month-old babies. And then she would simply put 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? the remarkable thing was that 18 month-old babies, just walking and talking, would give her the crackers if she liked the crackers, they would give her the broccoli if she liked broccoli. On the other hand, 15 month-olds would stare at her for a long time she acted as if she liked the broccoli, like they couldn’t figure out. But then after they stared for a long time, they would just give her the crackers, they thought everybody must like. So there are two really remarkable things about this. first one is that these little 18 month-old babies already discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they felt that they should actually do things help other people get what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds had learned this deep, fact about human nature in the three months from when were 15 months old. So children both know more and learn more than ever would have thought. And this is just one of hundreds and hundreds of studies over 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 is possible for them to learn so much in such a short time? mean, after all, if you look at babies superficially, they seem useless. And actually in many ways, they’re worse than useless, because we have to put so time and energy into just keeping them alive. But if we turn to evolution for an to this puzzle of why we spend so much time care of useless babies, it turns out that there’s actually an answer. If look across many, many different species of animals, not just us primates, but also including mammals, birds, even marsupials like 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 and flexible they are.
And sort of the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as smart as chimpanzees in respects. And this is a bird on the cover science who’s learned how to use a tool to get food. On the other hand, we have friend the domestic chicken. And chickens and ducks and geese turkeys are basically as dumb as dumps. So they’re very, very good at pecking for grain, and they’re much good at doing anything else. Well it turns out that babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little mouths for as long as two years, which is really long time in the life of a bird. the chickens are actually mature within a couple of months. So childhood is the reason the crows end up on the cover of Science and the chickens end up in soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what kind of explanation could we have this? Well some animals, like the chicken, seem to be suited to doing just one thing very well. So they seem to be beautifully to pecking grain in one environment. Other creatures, like crows, aren’t very good at doing anything in particular, but they’re extremely good at about laws of different environments.
And of course, we beings are way out on the end of the distribution like the crows. We have bigger relative to our bodies by far than any other animal. We’re smarter, we’re more flexible, can 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 on us much longer than the babies of any other species. son is 23. (Laughter) And at least until they’re 23, we’re popping those worms into those little open mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, is extremely powerful, great strategy for getting on in the world, but it has one disadvantage. And that one big disadvantage is that, until you actually all that learning, you’re going to be helpless. So you don’t want to have the mastodon charging you and be saying to yourself, “A slingshot or maybe 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 kind of division of labor. So the idea is that we have this early period we’re completely protected. We don’t have to do anything. All we have to do is learn. And as adults, we can take all those things that we learned we were babies and children and actually put them to work to do things out in the world.
So one way of thinking about is that babies and young children are like the research and development division of the human species. they’re the protected blue sky guys who just have to go out and learn and have ideas, and we’re production and marketing. We have to take all ideas that we learned when we were children and actually put them to use. Another of thinking about it is instead of thinking of babies and children as being like defective grownups, should think about them as being a different developmental of the same species — kind of like caterpillars and — except that they’re actually the brilliant butterflies who are flitting around the and exploring, and we’re the caterpillars who are inching our narrow, grownup, adult path.
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If this true, if these babies are designed to learn — and this evolutionary story would say children are learning, that’s what they’re for — we might expect that they would have powerful learning mechanisms. And in fact, the baby’s brain seems to be the most powerful computer on the planet. But real computers are actually getting to be a lot better. And there’s a revolution in our understanding of machine learning recently. And it all on the ideas of this guy, the Reverend Thomas Bayes, was 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 the world. So scientists do is they have a hypothesis that they might be likely to start with. They go out test it against the evidence. The evidence makes them that hypothesis. Then they test that new hypothesis and so on and so forth. And what Bayes showed a mathematical way that you could do that. And that mathematics is the core of the best machine learning programs that have now. And some 10 years ago, I suggested that babies might be doing same thing.
So if you want to know what’s going underneath those beautiful brown eyes, I think it actually looks like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional that they’re revising to figure out how the world works. right, now that might seem like an even taller to actually demonstrate. Because after all, if you ask even about statistics, they look extremely stupid. How could it that children are doing statistics?
So to test this we used a machine that we have called the Detector. This is a box that lights up and plays music you put some things on it and not others. And using this very simple machine, my lab others have done dozens of studies showing just how babies are at learning about the world. Let me 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 of the detector. But actually, this detector works in a bit a strange way. Because if you wave a block over the top the detector, something you wouldn’t ever think of to begin with, the detector will actually two out of three times. Whereas, if you do the likely thing, put the block on detector, it will only activate two out of six times. So the unlikely hypothesis actually stronger evidence. It looks as if the waving is a more strategy than the other strategy. So we did just this; we gave four year-olds this pattern evidence, and we just asked them to make it go. sure enough, the four year-olds used the evidence to the object on top of the detector.
Now there are two that are really interesting about this. The first one is, again, remember, are four year-olds. They’re just learning how to count. unconsciously, they’re doing these quite complicated calculations that will give them 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 unlikely 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 are when give them exactly the same task. So in these circumstances, the are using statistics to find out about the world, but all, scientists also do experiments, and we wanted to see if children are experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of studies recently that have shown this playing around is a kind of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did 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 boy will go through five hypotheses in the space of two minutes.
(Video) Boy: How this? Same as the other side.
Alison Gopnik: Okay, his first hypothesis has just been falsified.
(Laughter)
Boy: This lighted up, and this one nothing.
AG: Okay, he’s got experimental notebook out.
Boy: What’s making this light up. (Laughter) don’t know.
AG: Every scientist will recognize that expression despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, and 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. 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 fourth hypothesis.
Boy: It’s lighting up. So when you 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 — 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, they 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 to be kind of creature? What’s it like to be one of these brilliant butterflies who can five hypotheses in two minutes? Well, if you go back to psychologists and philosophers, a lot of them have said that babies young children were barely conscious if they were conscious all. And I think just the opposite is true. I babies and children are actually more conscious than we as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant important, we should pay attention to it. Our consciousness that thing that we’re attending to becomes extremely bright and vivid, and everything else of goes dark. And we even know something about the the brain does this.
So what happens when we pay attention is the prefrontal cortex, the sort of executive part of our brains, a signal that makes a little part of our brain much flexible, more plastic, better at learning, and shuts down activity all the rest of our brains. So we have a focused, purpose-driven kind of attention. If we look at babies and young children, we see 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 just thing. But they’re very good at taking in lots 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. So when we say that babies young children are bad at paying attention, what we really mean that they’re bad at not paying attention. So they’re at 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 might expect from those who are designed to learn.
Well if we want to think about a of getting a taste of that kind of baby consciousness as adults, think the best thing is think about cases where we’re put a new situation that we’ve never been in before — when 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 more full of consciousness and than all the months of being a walking, talking, faculty meeting-attending zombie back home. And by way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics effect of those baby neurotransmitters. So what’s it like be a baby? It’s like being in love in Paris for first time after you’ve had three double-espressos. (Laughter) That’s fantastic way to be, but it does tend to you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say too much about wonderful babies are. It’s good to be a grownup. can do things like tie our shoelaces and cross street by ourselves. And it makes sense that we a lot of effort into making babies think like adults do. But if what want is to be like those butterflies, to have open-mindedness, learning, imagination, creativity, innovation, maybe at least some of the time we should be getting the to start thinking more like children.
(Applause)