What is on in this baby’s mind? If you’d asked people 30 years ago, most people, including psychologists, would have said this baby was irrational, illogical, egocentric — that he couldn’t take the perspective of another person or understand cause effect. In the last 20 years, developmental science has 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. One thing this baby could be thinking about, that could be going on his mind, is trying to figure out what’s going on in the mind of that baby. After all, one of the things that’s hardest for all of us to do is to figure what other people are thinking and feeling. And maybe the hardest of all is to figure out that what other people and feel isn’t actually exactly like what we think and feel. who’s followed politics can testify to how hard that is for people to get. We wanted to know if babies young children could understand this really profound thing about people. Now the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old to you what he thinks, what you’ll get is a beautiful stream of consciousness monologue about ponies and birthdays things like that. So how do we actually ask them the question?
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it 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. all of the babies, even in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take little taste of food from each bowl. And she would act as if she it or she didn’t. So half the time, she acted 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 little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would a little bit of the crackers, and she’d go, “Eww, yuck, crackers. tasted the crackers. Eww, yuck.” So she’d act as if she wanted was just the opposite of what the babies wanted. We did this 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: would the baby give her, what they liked or she liked? And the remarkable thing was that 18 month-old babies, just walking and talking, would give her the crackers if liked the crackers, but they would give her the broccoli she liked the broccoli. On the other hand, 15 month-olds would stare at her a long time if she acted as if she liked broccoli, like they couldn’t figure this out. But then after they for a long time, they would just give her the crackers, what thought everybody must like. So there are two really remarkable things about this. The first one that these little 18 month-old babies have already discovered this really fact about human nature, that we don’t always want same thing. And what’s more, they felt 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 this suggests that these 18 month-olds had learned this deep, profound fact 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 hundreds and hundreds of studies over the last 20 years that’s actually demonstrated it.
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question you might ask though is: Why do children learn so much? And is it possible for them to learn so much in such 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 put so much time and energy into just keeping them alive. if we turn to evolution for an answer to this puzzle of why we spend much time taking care of useless babies, it turns out that there’s actually answer. If we look across many, many different species of animals, just us primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, it turns out there’s a relationship between how long a childhood a species has and how their brains are compared to their bodies and how smart and flexible are.
And sort of the posterbirds for this idea the birds up there. On one side is a New crow. And crows and other corvidae, ravens, rooks and so forth, incredibly smart birds. They’re as smart as chimpanzees in some respects. And this a 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 chicken. And chickens and ducks and geese and turkeys basically as dumb as dumps. So they’re very, very good at for grain, and they’re not much good at doing else. Well it turns out that the babies, the Caledonian crow babies, are fledglings. They depend on their moms to drop worms in their open 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 why the crows up on the cover of Science and the chickens up in the soup pot.
There’s something about that childhood that seems 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 beautifully suited to doing just one very well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t very good doing anything in particular, but they’re extremely good at about laws of different environments.
And of course, we human beings are out on the end of the distribution like the crows. We have bigger brains to our bodies 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 go outer space. And our babies and children are dependent on us for much than the babies of any other species. My son 23. (Laughter) And at least until they’re 23, we’re still popping worms into those little open mouths.
All right, why we see this correlation? Well an idea is that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it one big 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 a spear work. Which would actually be better?” You want to know all that 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 have 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 all those things that we learned when we were babies and children and actually put them work to do things out there in the world.
So one way of thinking about it is that babies young children are like the research and development division of human species. So they’re the protected blue sky guys who just have to 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 way of thinking about it is of thinking of babies and children as being like defective grownups, we should think about them being a different developmental stage of the same species — of like caterpillars and butterflies — except that they’re actually the brilliant butterflies who are around the garden and exploring, and we’re the caterpillars who inching along our narrow, grownup, adult path.
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If this is true, these babies are designed to learn — and this story would say children are for learning, that’s what they’re for — might expect that they would have really powerful learning mechanisms. And fact, the baby’s brain seems to be the most powerful learning computer the planet. But real computers are actually getting to be a lot better. And there’s been a revolution our understanding of machine learning recently. And it all depends on the ideas this guy, the Reverend Thomas Bayes, who was a and mathematician in the 18th century. And essentially what Bayes did was to provide a mathematical way using theory to characterize, describe, the way that scientists find out about world. So what scientists do is they have a hypothesis they think might be likely to start with. They go out and test against the evidence. The evidence makes them change that hypothesis. Then they test new hypothesis and so on and so forth. And what Bayes was a mathematical way that you could do that. And that mathematics is at the of the best machine learning programs that we have now. And some 10 years ago, I suggested that might be doing the same thing.
So if you want know what’s going on underneath those beautiful brown eyes, I think it actually something like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, now that might like an 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 test this we used machine that we have called the Blicket Detector. This a box that lights up and plays music when you put things on it and not others. And using this very simple machine, my and others have done dozens of studies showing just how babies are at learning about the world. Let me mention one that we did with Tumar Kushner, my student. I showed you this detector, you would be likely to think to begin that 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 block over the top of the detector, you wouldn’t ever think of to begin with, the detector will actually activate two of three times. Whereas, if you do the likely thing, put the on the detector, it will only activate two out of six times. So unlikely hypothesis actually has stronger evidence. It looks as if waving is a more effective strategy than the other strategy. So we did just this; we four year-olds this 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 the detector.
Now there are two 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 will give them a conditional measure. And the other interesting thing is that they’re that evidence to get to an idea, get to a hypothesis about the world, seems very unlikely to begin with. And in studies we’ve just been doing my lab, similar studies, we’ve show that four year-olds are actually better finding out an unlikely hypothesis than adults are when we give exactly the same task. So in these circumstances, the children 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 into everything” or “playing.”
And there’s been a bunch of interesting studies that have shown this playing around is really a of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did was use Blicket Detectors. And what she did was show children that yellow made it 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 space of two minutes.
(Video) Boy: How about this? as the other side.
Alison Gopnik: Okay, so his hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s this light up. (Laughter) I don’t know.
AG: Every will recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, and this to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told 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 this box has electricity in 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 and two on one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is a — that is a particularly adorable and articulate little boy, but what Cristine discovered is this is actually typical. If you look at the way children play, you ask them to explain something, what they really do is do series of experiments. This is actually 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 be of these brilliant butterflies who can test five hypotheses in two minutes? Well, if you go to those psychologists and philosophers, a lot of them have said that babies and young children barely conscious if they were conscious at all. And I just the opposite is true. I think babies and children are actually conscious than we are as adults. Now here’s what know about how adult consciousness works. And adults’ attention consciousness look kind of like a spotlight. So what happens for is we decide that something’s relevant or important, we should pay attention it. Our consciousness of that thing that we’re attending to becomes bright and vivid, and everything else sort of goes dark. And we even know about the way the brain does this.
So what happens when pay attention is that the prefrontal cortex, the sort of executive part of our brains, sends a that makes a little part of our brain much flexible, more plastic, better at learning, and shuts down activity in the rest of our brains. So we have a very focused, purpose-driven kind of attention. If look at babies and young children, we see something different. I think babies and young children seem to have of a lantern of consciousness than a spotlight of consciousness. So babies young children are very bad at narrowing down to one thing. But they’re very good at taking in of information from lots of different sources at once. if you actually look in their brains, you see they’re flooded with these neurotransmitters that are really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say babies and young children are bad at paying attention, what really mean is that they’re bad at not paying attention. So they’re bad at getting rid all the interesting things that could tell them something just looking at the thing that’s important. That’s the of attention, the kind of consciousness, that we might expect from those butterflies are designed to learn.
Well if we want to think about a way of getting 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 fall in with someone new, or when we’re in a new city for the first time. And what happens is not that our consciousness contracts, it expands, so that those three in Paris seem to be more full of consciousness experience than all the months of being a walking, talking, faculty meeting-attending zombie home. And by the way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics effect of those baby neurotransmitters. So what’s it like to be baby? It’s like being in love in Paris for the time after you’ve had three double-espressos. (Laughter) That’s a 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 a grownup. We can do things like tie our shoelaces and cross street by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But what we want is to be like those butterflies, to have open-mindedness, learning, imagination, creativity, innovation, maybe at least some of the time we should getting the adults to start thinking more like children.
(Applause)