What going on in this baby’s mind? If you’d asked people this 30 ago, most people, including psychologists, would have said that baby was irrational, illogical, egocentric — that he couldn’t the perspective of another person or understand cause and effect. In the 20 years, developmental science has completely overturned that picture. So in some ways, think that this baby’s thinking is like the thinking of the most scientists.
Let me give you just one example of this. One thing that this baby be thinking about, that could be going on in his mind, is to figure out what’s going on in the mind of that other baby. After all, of the things that’s hardest for all of us do is to figure out what other people are thinking feeling. And maybe the hardest thing of all is to figure out that other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can to how hard that is for some people to get. wanted to know if babies and young children could understand this really profound thing about other people. the question is: How could we ask them? Babies, after all, can’t talk, if you ask a three year-old to tell you what he thinks, what you’ll get is a stream of consciousness monologue about ponies and birthdays and things like that. So do we actually ask them the question?
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Well turns out that the secret was broccoli. What we did — Betty Rapacholi, was one of my students, and I — was actually give the babies two bowls of food: one bowl of raw broccoli one bowl of delicious goldfish crackers. Now all of the babies, even Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But then what Betty did to take a little taste of food from each bowl. And she act as if she liked it or she didn’t. So half the time, acted as if she liked the crackers and didn’t like the broccoli — just like a and any other sane person. But half the time, what she would do take a little bit of the broccoli and go, “Mmmmm, broccoli. tasted the 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 wanted was just the opposite of what the babies wanted. did this with 15 and 18 month-old babies. And then she simply put her hand out 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 barely and talking, would give her the crackers if she liked the crackers, but would give her the broccoli if she liked the broccoli. On the hand, 15 month-olds would stare at her for a time if she acted as if she liked the broccoli, they couldn’t figure this out. But then after they for a long time, they would just give her the crackers, what they thought 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 profound fact about human nature, that we don’t always the same thing. And what’s more, they felt that they should actually do things to help people get what they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t do this suggests 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 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 though is: Why do children learn so much? And how it possible for them to learn so much in a short time? I mean, after all, if you 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 if we to evolution for an answer to this puzzle of why we so much time taking care of useless babies, it turns out that there’s an answer. If we look across many, many different species of animals, not just us primates, also including other mammals, birds, even marsupials like kangaroos wombats, it turns out that there’s a relationship between how long a childhood a has and how big 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 Caledonian crow. crows and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as as chimpanzees in some respects. And this is a on the cover of science who’s learned how to use a tool to get food. On other hand, we have our friend the domestic chicken. And chickens and ducks and geese turkeys are basically as dumb as dumps. So they’re very, very at pecking for grain, and they’re not much good at doing else. Well it turns out that the babies, the New Caledonian 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 within a couple of months. So is the reason why the crows end up on the cover of Science and the chickens end in the soup pot.
There’s something about that long childhood seems to be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, like the chicken, seem to be suited to doing just one thing very well. So they seem to be suited to pecking grain in one environment. Other creatures, like the crows, aren’t very good at doing anything particular, but they’re extremely good at learning about laws different environments.
And of course, we human beings are way out the end of the distribution like the crows. We bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can learn more, survive in more different environments, we migrated to cover the world and even go outer space. And our babies and children are dependent us for much longer than the babies of any other species. My son is 23. (Laughter) at least until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see this correlation? Well an idea that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it has one big disadvantage. that one big disadvantage is that, until you actually do that learning, you’re going to be helpless. So you don’t want to have the charging at you and be saying to yourself, “A slingshot maybe a spear 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 a 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 when we were babies and and actually put them to work to do things there in the world.
So one way of thinking about it that babies and young children are like the research and division of the human species. So they’re the protected sky guys who just have to go out and learn have good ideas, and we’re production and marketing. We have take all those ideas that we learned when we children and actually put them to use. Another way of thinking it is instead of thinking of babies and children as being defective grownups, we should think about them as being a different developmental stage of the same species — of like caterpillars and butterflies — except that they’re the brilliant butterflies who are flitting around the garden exploring, and we’re the caterpillars who are inching along 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 are for learning, that’s what they’re for — we might expect that they would have really learning mechanisms. And in fact, the baby’s brain seems be the most powerful learning computer on the planet. real computers are actually getting to be a lot better. And there’s been a revolution in our of machine learning recently. And it all depends on ideas of this guy, the Reverend Thomas Bayes, who 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 the world. So what scientists do is they have hypothesis that they think might be likely to start with. They out and test it against the evidence. The evidence makes them change that hypothesis. Then they that new hypothesis and so on and so forth. And Bayes showed was 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 the 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 think those babies actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, now might seem like an even taller order to actually demonstrate. after all, if you ask even grownups about statistics, they look extremely stupid. How could it be that are doing statistics?
So to test this we used a machine that we have called the Blicket Detector. is a box that lights up and plays music when you put some on it and not others. And using this very simple machine, my lab and others have done of studies showing just how good babies are at learning about the world. me mention just one that we did with Tumar Kushner, student. If I showed you this detector, you would be likely to think to with that the way to make the detector go would to put a block on top of the detector. But actually, this works in a bit of a strange way. Because if 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, you 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 more 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 go. And sure enough, the four year-olds used the evidence wave the object on top of the detector.
Now are two things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning how to count. unconsciously, they’re doing these quite complicated calculations that will give a conditional probability measure. And the other interesting thing is that they’re that evidence to get to an idea, get to hypothesis about the world, that seems very unlikely to with. And in studies we’ve just been doing in my lab, similar studies, we’ve show four year-olds are actually better at finding out an hypothesis than adults are when we give them exactly the same task. in these circumstances, the children are using statistics to out about the world, but after all, scientists also do experiments, and we wanted see if children are doing experiments. When children do experiments we call it “getting into everything” or “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 our Blicket Detectors. And what she did was show children yellow ones made it go and red ones didn’t, and then showed them an anomaly. And what you’ll see is that this little boy go through five hypotheses in the 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 up, and this one nothing.
AG: Okay, he’s got his 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 like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his idea. He told the experimenter to do this, to try putting out onto the other location. Not working either.
Boy: Oh, because light goes only to here, not here. Oh, the bottom of this box has electricity in here, but doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s up. So when you put four. So you put four on this one to make it light and two on this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that a particularly adorable and articulate little boy, but what discovered is this is actually quite 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 to be this kind of creature? What’s it like be one of these brilliant butterflies who can test hypotheses in two minutes? Well, if you go back to those and philosophers, a lot of them have said that babies and children were barely conscious if they were conscious at all. I think just the opposite is true. I think 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 like a spotlight. So what happens for adults is we decide something’s relevant or important, we should pay attention to it. Our consciousness of that thing that we’re attending to extremely bright and vivid, and everything else sort of goes dark. And we know something about the way the brain does this.
So what happens we pay attention is that the prefrontal cortex, the of executive part of our brains, sends a signal that makes little part of our brain much more flexible, more plastic, better at learning, shuts down activity in all the rest of our brains. So we have very focused, purpose-driven kind of attention. If we look babies and young children, we see something very different. think babies and young children seem to have more a lantern of consciousness than a spotlight of consciousness. babies and young children are very bad at narrowing down just one thing. But they’re very good at taking in lots information from lots of different sources at once. And if you actually look in their brains, you that 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 we really mean that they’re bad at not paying attention. So they’re bad at getting rid of the interesting things that could tell them something and looking at the thing that’s important. That’s the kind of attention, kind of consciousness, that we might expect from those butterflies who are designed to learn.
Well if we to think about a way of getting a taste of that of baby consciousness as adults, I think the best thing is think about cases where we’re 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 for the first time. what happens then is not that our consciousness contracts, it expands, so that three days in Paris seem to be more full consciousness and experience than all the months of being a walking, talking, faculty meeting-attending zombie back home. 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 baby? It’s like being in love in Paris for the first after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it does tend to leave 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 about how wonderful babies are. It’s good to be a grownup. We can things like tie our shoelaces and cross the street by ourselves. And makes sense that we put a lot of effort into making think like adults do. But if what we want to be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be getting the adults start thinking more like children.
(Applause)