What is going on in this baby’s mind? If you’d people this 30 years ago, most people, including psychologists, would have said that 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 completely overturned that picture. So 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 thinking about, that could be going on his mind, is trying to figure out what’s going on in the mind of that other baby. all, one of the things that’s hardest for all of us to is to figure out what other people are thinking and feeling. And maybe hardest thing of all is to figure out that what other people think and feel isn’t actually exactly what we think and feel. Anyone who’s followed politics can testify to how hard is for some people to get. We wanted to know babies and young children could understand this really profound thing about other people. Now the question is: could we ask them? Babies, after all, can’t talk, and if you a three year-old to tell you what he thinks, you’ll get is a beautiful stream of consciousness monologue about and birthdays and things like that. So how do actually ask them the question?
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Well it out that the secret was broccoli. What we did — Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: bowl of raw broccoli and one bowl of delicious crackers. Now all of the babies, even in Berkley, like crackers and don’t like the raw broccoli. (Laughter) But then what Betty did to take a little taste of food from each bowl. she would act as if she liked it or didn’t. So half the time, she acted as if liked the crackers and didn’t like the broccoli — like a baby and any other sane person. But half the time, she would do is take a little bit of the 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 what wanted was just the opposite of what the babies wanted. did this with 15 and 18 month-old babies. And then she would simply put her hand out say, “Can you give me some?”
So the question is: What would the baby give her, what liked or what she liked? And the remarkable thing was that 18 month-old babies, barely walking and talking, would 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 liked the broccoli, like they couldn’t figure out. But then after they stared for a long time, they just give her the crackers, what they thought everybody must like. So there are really remarkable things about this. The first one is these little 18 month-old babies have already discovered this profound fact 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 get what they wanted.
Even more though, the fact that 15 month-olds didn’t do this suggests that 18 month-olds had learned this deep, profound fact about human nature in 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 just one of and hundreds of studies over the last 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 in such a short time? I mean, after all, if you look at babies superficially, they pretty useless. And actually in many ways, they’re worse than useless, because we to put so much time and energy into just 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 out that there’s actually an answer. If we look across many, many species of animals, not just us primates, but also including other mammals, birds, even marsupials 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 this idea are the birds up there. On one side a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird on the cover science who’s learned how to use a tool to get food. On the hand, we have our friend the domestic chicken. And chickens and 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 doing anything else. Well it turns out that the babies, the New crow babies, are fledglings. They depend on their moms to drop worms their little open mouths for as long as two years, which is a really long in the life of a bird. Whereas the chickens are actually mature a couple of months. So childhood is the reason why crows end up on the cover of Science and the 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 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 grain in one environment. creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about of different environments.
And of course, we human beings are way out the end of the distribution like the crows. We have bigger brains relative to our bodies by than any other animal. We’re smarter, we’re more flexible, we learn more, we survive in more different environments, we migrated to cover world and even go to outer space. And our and children are dependent on us for much longer than the babies of other species. My son is 23. (Laughter) And at least they’re 23, we’re still popping those worms into those little mouths.
All right, why would we see this correlation? Well an idea is that strategy, that learning strategy, is an extremely powerful, great strategy for getting on in the world, but has 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 to have the mastodon charging at and be saying to yourself, “A slingshot or maybe a spear might work. Which would be better?” You want to know all that before the mastodons actually show up. And the the evolutions seems to have solved that problem is with kind of division of labor. So the idea is that we have this early when we’re completely protected. We don’t have to do anything. All we have to do is learn. And then adults, we can take all those things that we learned when we were babies and children and put them to work to do things out there in the world.
So way of thinking about it is that babies and young are like the research and development division of the species. So they’re the protected blue sky guys who 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 put to use. Another way of thinking about it is instead of thinking babies and children as being like defective grownups, we think about them as being a different developmental stage the same species — kind of like caterpillars and — except that they’re actually the brilliant butterflies who flitting around the garden and exploring, and we’re the who are inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to learn — this evolutionary story would say children are for learning, that’s what they’re for — might expect that they would have really powerful learning mechanisms. And in fact, the baby’s brain seems be the most powerful learning computer on the planet. But computers are actually getting to be a lot better. And there’s been a in our understanding of machine learning recently. And it depends on the ideas of this guy, the Reverend Bayes, who was a statistician and 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 find out the world. So what scientists do is they have a hypothesis that they think might likely to start with. They go out and test it against the evidence. The evidence them change that hypothesis. Then they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way you could do that. And that mathematics is at the of the best machine learning programs that we have now. And some 10 ago, I suggested that babies might be doing the same thing.
So if you want to what’s going on underneath those beautiful brown eyes, I think it actually looks something this. This is Reverend Bayes’s notebook. So I think babies are actually making complicated calculations with conditional probabilities that they’re revising to figure out the world works. All right, now that might seem an even taller order to actually demonstrate. Because after all, you ask even grownups about statistics, they look extremely stupid. How could be that children are doing statistics?
So to test this we a machine that we have called the Blicket Detector. is a box that lights up and plays music 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 the world. Let me mention one that we did with Tumar Kushner, my student. If I you this detector, you would be likely to think to begin with that the way to make detector go would be to put a block on of the detector. But actually, this detector works in bit 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, the detector will activate two out of three times. Whereas, if you the likely thing, put the block on the detector, it will only two out of six times. So the unlikely hypothesis has stronger evidence. It looks as if the waving a more effective strategy than the other strategy. So we did just this; gave four year-olds this pattern of evidence, and we just asked them make it go. And sure enough, the four year-olds used the evidence wave the object on top of the detector.
Now there are two things that are interesting about this. The first one is, again, remember, are four year-olds. They’re just learning how to count. But unconsciously, they’re these quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re using that to get to an idea, get to a hypothesis the world, that seems very unlikely to begin with. And in studies we’ve just doing in my lab, similar studies, we’ve show that year-olds are actually better at finding out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, the children are using statistics find out about the world, but after all, scientists also experiments, and we wanted to see if children are doing experiments. When 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 kind 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 made it go and red ones didn’t, and then showed them 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 one up, and 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 scientist recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because needs to be like this, and this needs to be this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He the 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 of 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 you put four on this to make it light up and two on this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that is particularly adorable and articulate little boy, but what Cristine is this is actually quite typical. If you look 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 like to be 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 back to those psychologists and philosophers, a lot of them have said that babies and young children were conscious if they were conscious at all. And I think the opposite is true. I think babies and children are actually more than we are as adults. Now here’s what we know about how adult consciousness works. And adults’ attention consciousness look kind of like a spotlight. So what for adults is we decide that something’s relevant or important, should pay attention to it. Our consciousness of that that we’re attending to becomes extremely bright and vivid, everything else sort of goes dark. And we even know about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a signal that makes little part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest of brains. So we have a very focused, purpose-driven kind attention. If we look at babies and young children, we see something very different. think babies and young children seem to have more of a lantern of consciousness a spotlight of consciousness. So babies and young children are very bad narrowing down to just one thing. But they’re very good at in lots of information 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 learning and plasticity, and the parts haven’t come on yet. So when we say babies and young children are bad at paying attention, we really mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting things that could tell them and just looking at the thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from butterflies who are designed to learn.
Well if we to think about a way of getting a taste that kind of baby consciousness as adults, I think the thing is think about cases where we’re put in a new situation that we’ve never in before — when we fall in love with someone new, or when we’re a new city for the first time. And what happens then is not our consciousness contracts, it expands, so that those three in Paris seem to be more full of consciousness and experience 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, mimics the effect of those baby neurotransmitters. So what’s it to be a baby? It’s like being in love Paris for the first time after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, it does tend to leave you waking up crying three o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want to say much about how wonderful babies are. It’s good to a grownup. We can do things like tie our shoelaces and the street by ourselves. And it makes sense that put a lot of effort into making babies think like adults do. But if what we want is be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of the time should be getting the adults to start thinking more children.
(Applause)