What is going in this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, have said that this baby was irrational, illogical, egocentric — that he couldn’t take the of another person or understand cause and effect. In the last 20 years, science has completely overturned that picture. So in some ways, we think that baby’s thinking is like the thinking of the most 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 hardest for of us to do is to figure out what people are thinking and feeling. And maybe the hardest thing all is to figure out that what other people think 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 other people. Now the question is: How 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 turns out that the secret was broccoli. What did — Betty Rapacholi, who was one of my students, and — was 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, the crackers and don’t like the raw broccoli. (Laughter) then what Betty did was to take a little taste of food from each bowl. And would act as if she liked 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 any other sane person. But half the time, what she would do is take a little bit of broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” then she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” she’d act as if what she wanted was just opposite of 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 the question is: What would the give her, what they liked or what she liked? And the remarkable thing was 18 month-old babies, just barely walking and talking, would give the crackers if she liked the crackers, but they would give her the if she liked the broccoli. On the other hand, 15 month-olds would stare at her for a long time if 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 these little 18 month-old babies have already discovered this really profound fact about human nature, that we don’t 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 though, the fact that 15 month-olds didn’t do this suggests these 18 month-olds had learned this deep, profound fact about human nature in the three months when they were 15 months old. So children both know more and learn more than we ever have thought. And this is just one of hundreds and hundreds of studies 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? how 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, we have to put so much time and energy into just them alive. But if we turn to evolution for an answer this puzzle of why we spend so much time taking care of babies, it turns out that there’s actually an answer. If we look many, many different species of animals, not just us primates, but also including mammals, birds, even marsupials like kangaroos and wombats, it turns out there’s a relationship between how long a childhood a species and how big their brains are compared to their bodies and how smart and flexible they are.
And of the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows and other corvidae, ravens, rooks and forth, are incredibly smart birds. They’re as smart as chimpanzees in respects. And this is a bird on the cover of science who’s learned how use a tool to get food. On the other hand, we have our friend domestic chicken. And chickens and ducks and geese and are basically as dumb as dumps. So they’re very, very at pecking for grain, and they’re not much good at doing anything else. Well turns out that the babies, the New Caledonian crow babies, are fledglings. They depend their moms to drop worms in their little open for as long as two years, which is a 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 up on the cover of Science and the chickens end in the soup pot.
There’s something about that long that seems to be connected to knowledge and learning. Well what kind of could we have for this? Well some animals, like 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 at doing anything in particular, but they’re good at learning about laws of different environments.
And 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 more, we survive in more different environments, we migrated to cover the world even go to outer space. And our babies and children are dependent on us much longer than the babies of any other species. My son 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? Well idea is that that strategy, that learning strategy, is an extremely powerful, 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 don’t want to have the mastodon charging at you and be saying to yourself, “A slingshot maybe a spear might work. Which would actually be better?” You want to all that before the mastodons actually show up. And way the evolutions seems to have solved that problem is with a kind of of labor. So the idea is that we have this period when we’re completely protected. We don’t have to do anything. All we to do is learn. And then as adults, we take all those things that we learned when we babies and children and actually put them to work to things out there in the world.
So one way of about it is that babies and young children are like research and development division of the human species. So they’re the protected blue sky who just have to go out and learn and have good ideas, and we’re production marketing. We have to take all those ideas that learned when we were children and actually put them 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 stage the same species — kind of like caterpillars and butterflies — 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 is true, if these babies designed to learn — and this evolutionary story would say children for learning, that’s what they’re for — we might expect they would have really powerful learning mechanisms. And in fact, the baby’s brain seems to be most powerful learning computer on the planet. But real computers actually getting to be a lot better. And there’s been revolution in our understanding of machine learning recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician and mathematician in the 18th century. And essentially what did was to provide a mathematical way using probability to 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 and test it the evidence. The evidence makes them change that hypothesis. Then they test new hypothesis and so on and so forth. And what showed was a mathematical way that you could do that. And mathematics is at the core of the best machine learning that we have now. And some 10 years ago, I suggested babies might be doing the same thing.
So if you want know what’s going on underneath those beautiful brown eyes, think it actually looks something like this. This is Bayes’s notebook. So I think those babies are actually making complicated with conditional probabilities that they’re revising to figure out how the works. All right, now that might seem like an even order to actually demonstrate. Because after all, if you ask even grownups statistics, they look extremely stupid. How could it be children are doing statistics?
So to test this we a machine that we have called the Blicket Detector. This is a box that lights up and music when you put some things on it and not others. And using this very simple machine, lab and others have done dozens of studies showing how good babies are at learning about the world. me mention just one that we did with Tumar Kushner, my student. If I showed you detector, you would be likely to think to begin with that the way to make the detector would be to put a block on top of the detector. But actually, this detector works a bit 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 will actually activate two out of three times. Whereas, if do the likely thing, put the block on the detector, it will only activate two of six times. So the unlikely hypothesis actually has evidence. It looks as if the waving is a effective strategy than the other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked them to make it go. And enough, the four year-olds used the evidence to wave object on top of the detector.
Now there are two things that are really interesting this. The first one 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 using that evidence to get to an idea, get a hypothesis about the world, that seems very unlikely to with. And in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better finding out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, the are using statistics to find out about the world, but after all, also do experiments, and we wanted to see if children doing experiments. When children do experiments we call it “getting 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. What Cristine did was use our Blicket Detectors. And she did was show children that yellow ones made it go red ones didn’t, and then she showed them an anomaly. what you’ll see is that this little boy will go through five 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: one lighted up, and this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this up. (Laughter) I don’t know.
AG: Every scientist will recognize that expression of despair.
(Laughter)
Boy: Oh, it’s this needs to be like this, and this needs to like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. told the experimenter to do this, to try putting out onto the other location. Not working either.
Boy: Oh, the light goes only to here, not here. Oh, bottom of this box has electricity in here, but doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So when you put four. you put four on this one to make it light up and two on one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is a adorable and articulate little boy, but what Cristine discovered this is actually quite typical. If you look at the way children play, when you ask to explain something, what 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 brilliant butterflies who can test five hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have said that babies and young were barely conscious if they were conscious at all. And I think just opposite is true. I think babies and children are more conscious than we are as adults. Now here’s we know about how adult consciousness works. And adults’ and consciousness look kind of like a spotlight. So what happens for adults is we decide that something’s or important, we should pay attention to it. Our consciousness of that thing that we’re to becomes extremely bright and vivid, and everything else sort of dark. And we even know something about the way the brain does this.
So happens when we pay attention is that the prefrontal cortex, the sort of executive part of our brains, a signal that makes a little part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest of our brains. So 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 more of lantern of consciousness than a spotlight of consciousness. So and young children are very bad at narrowing down to just thing. But they’re very good at taking in lots of information from lots different sources at once. And if you actually look in brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and inhibitory parts haven’t come on yet. So when we say that babies young children are bad at paying attention, what we mean is that they’re bad at not paying attention. So they’re bad at getting rid of all interesting things that could tell them something and just looking at the that’s important. That’s the kind of attention, the kind of consciousness, that might expect from those butterflies who are designed to learn.
Well if we want to about a way of getting a taste of that of baby consciousness as adults, I think the best thing think about cases where we’re put in a new situation that we’ve never been in before — we fall in love with someone new, or when we’re in a new city the first time. And what happens then is not our consciousness contracts, it expands, so that those three days in Paris to be more full of consciousness and experience than all the months of being walking, talking, faculty meeting-attending zombie back home. And by 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 double-espressos. (Laughter) That’s a fantastic way to be, but does tend to leave you waking up crying at o’clock in the morning.
(Laughter)
Now it’s good to be grownup. I don’t want to say too much about how wonderful babies are. It’s good to a grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that put a lot of effort into making babies think adults do. But if what we want is to 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)