What going on in this baby’s mind? If you’d asked 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 person or understand cause and effect. In the last 20 years, developmental science has overturned that picture. So in some ways, we think that this baby’s thinking is the thinking of the most brilliant scientists.
Let me you just one example of this. One thing that baby could be thinking about, that could be going on his mind, is trying to figure out what’s going 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 is to figure out that what other people think and feel isn’t actually exactly like what think and feel. Anyone who’s followed politics can testify to how that is for some people to get. We wanted to know if 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 you he thinks, what you’ll get is a beautiful stream of consciousness monologue about and birthdays and 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 one of my students, and I — was actually to give the babies two bowls of food: bowl of raw broccoli and one bowl of delicious goldfish crackers. Now all the babies, even in Berkley, like the crackers and don’t like raw broccoli. (Laughter) But then what Betty did was take a 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 as she liked the crackers and didn’t like the broccoli — just like a baby and any sane person. But half the time, what she would do is take a little bit the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a little bit of crackers, and she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d 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 put her hand out and say, “Can you give some?”
So the question is: What would the baby give her, they liked or what she liked? And the remarkable was that 18 month-old babies, just barely walking and talking, would give the crackers if she liked the crackers, but they would her the broccoli if she liked the broccoli. On the hand, 15 month-olds would stare at her for a long if 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, what they everybody must like. So there are two really remarkable things about this. The first one is that little 18 month-old babies have 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 do things to help other people get what they wanted.
Even 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 were 15 months old. So children both know more and more than we ever would have thought. And this is just one of hundreds and hundreds studies over the last 20 years that’s actually demonstrated it.
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The question you might ask is: Why do children learn so much? And how is it possible for to learn so much in such a short time? mean, after all, if you look at babies superficially, they seem pretty useless. And actually many ways, they’re worse than useless, because we have put so much time and energy into just keeping them alive. But we turn to evolution for an answer to this of why we spend so much time taking care of useless babies, it turns that there’s actually an answer. If we look across many, many different of animals, not just us primates, but also including mammals, birds, even marsupials like kangaroos and wombats, it out that there’s a relationship between how long a childhood a has and how big their brains are compared to their and how smart and flexible they are.
And sort of the posterbirds for this are the birds up there. On one side is a New crow. And crows and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird on the of science who’s learned how to use a tool to 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 anything else. Well it turns out that the babies, New Caledonian crow babies, are fledglings. They depend on moms to drop worms in their little open mouths for as long as two years, is a really long time in the life of a bird. Whereas 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 the pot.
There’s something about that long childhood that seems to be to knowledge and learning. Well what kind of explanation we have for this? Well some animals, like the chicken, seem be beautifully suited to doing just one thing very well. So they seem be beautifully suited to pecking grain in one environment. creatures, like the crows, aren’t very good at doing anything in particular, but they’re extremely good learning about laws of different environments.
And of course, we human beings are way out on the end 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 more different environments, we migrated to cover the world and even go to outer space. And babies and children are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that learning strategy, an extremely powerful, great strategy for getting on in the world, but it has one big disadvantage. And one big disadvantage is that, until you actually do all that learning, you’re to be helpless. So you don’t want to have the charging at you and be saying to yourself, “A slingshot or maybe a might work. Which would actually be better?” You want to know all that the mastodons actually show up. And the way the 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. then as adults, we can take all those things that we learned when we were babies and and actually put them to work to do things out there in the world.
So one way thinking about it is that babies and young children like the research and development division of the human species. So they’re the blue sky guys who just have to go out and learn and have good ideas, 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 thinking of babies and children as like defective grownups, we should think about them as being a different developmental of the same species — kind of like caterpillars and butterflies — except they’re actually the brilliant butterflies who are flitting around the garden exploring, and we’re the caterpillars who are inching along narrow, grownup, adult path.
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If this is true, if babies are designed to learn — and this evolutionary story would say are for learning, that’s what they’re for — we might that they would have really powerful learning mechanisms. And in fact, the baby’s brain seems to be the powerful learning computer on the planet. But real computers are actually getting to be a better. And there’s been a revolution in our understanding machine learning recently. And it all depends on the ideas this 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 that scientists find out about the world. So what scientists do is they have a hypothesis that they might be likely to start with. They go out and test it against the evidence. The makes them change that hypothesis. Then they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way that you could do that. that mathematics is at the core of the best machine learning programs that we have now. some 10 years ago, I suggested that babies might doing the same thing.
So if you want to know what’s going on 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 probabilities they’re revising to figure out how the world works. All right, now that might seem an even taller order to actually demonstrate. Because after all, if you even grownups about statistics, they look extremely stupid. How could it be that children are statistics?
So to test this we used a machine that we called the Blicket Detector. This is a box that lights and plays music when you put some things on it and not others. And this very simple 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, you be likely to think to begin with that the way to the detector go would be to put a block on 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 think of to begin with, detector will actually activate two out of three times. Whereas, you do the likely thing, put the block on detector, it will only activate two out of six times. So unlikely hypothesis actually has stronger evidence. It looks as the waving is a more effective strategy than the other strategy. So 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 two things that are really interesting about this. The first one is, again, remember, these four year-olds. They’re just learning how to count. But unconsciously, they’re doing these complicated 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 world, that seems very unlikely to begin with. And studies we’ve just been doing in my lab, similar studies, we’ve show that four year-olds are actually better at finding an unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using to find out about the world, but after all, also do experiments, and we wanted to see if children are doing experiments. When children experiments we call it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown this around is really a kind of experimental research program. Here’s from Cristine Legare’s lab. What Cristine did was use 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 see that this little boy will go through five hypotheses in space of two minutes.
(Video) Boy: How about this? Same as the 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 this light up. (Laughter) I don’t know.
AG: Every scientist will 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: this is his next idea. He told the experimenter to do this, to try putting out onto the other location. Not working either.
Boy: Oh, because the light goes only here, not here. Oh, the bottom of this box electricity in here, but this doesn’t have electricity.
AG: Okay, that’s fourth 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 particularly — that is a particularly adorable and articulate little boy, what Cristine discovered is this is actually quite typical. If you look at the way play, when you ask them to explain something, what they really do do a series of experiments. This is actually pretty typical four year-olds.
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Well, what’s it like to this kind of creature? What’s it like to be one of these butterflies who can test five hypotheses in two minutes? Well, if you go to those psychologists and philosophers, a lot of them have that babies and young children were barely conscious if they were conscious all. And I think just the opposite is true. I think babies children are actually more conscious than we are as adults. Now here’s what know about how adult consciousness works. And adults’ attention and consciousness look kind of like a spotlight. what happens for adults is we decide that something’s relevant or important, we should pay to it. Our consciousness of that thing that we’re to becomes extremely bright and vivid, and everything else sort goes dark. And we even know something about the the brain does this.
So what happens when we pay is that the prefrontal cortex, the sort of executive part our brains, sends a signal that makes a little part our brain much more flexible, more plastic, better at learning, and shuts down activity in all the of our brains. So we have a very focused, purpose-driven kind of attention. we look at babies and young children, we see something very different. I think babies young children seem to have more of a lantern of consciousness than spotlight of consciousness. So babies and young children are very at narrowing down to just one thing. But they’re very good at taking in of information from lots of different sources at once. And if you actually in their brains, you see that they’re flooded with these neurotransmitters that are really at inducing learning 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 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 kind of attention, the kind of consciousness, we might expect from those butterflies who are designed to learn.
Well if we want to about a way of getting a taste of that kind of consciousness as adults, I think the best thing is think about cases where we’re put in a situation that we’ve never been in before — when we fall in love with new, or when we’re in a new city for the first time. And what happens then is that our consciousness contracts, it expands, so that those days in Paris seem to be more full of consciousness and experience all the months of being a walking, talking, faculty meeting-attending back home. And by the way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually the effect of those baby neurotransmitters. So what’s it like to be a baby? It’s like being love in Paris for the 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 how wonderful babies are. It’s good to be a grownup. We can do like tie our shoelaces and cross the street by ourselves. And it makes sense that we a lot of effort into making babies think like do. But if what we want is to be those butterflies, to have 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)