What going on in this baby’s mind? If you’d asked this 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 or understand cause and 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 you just one example of this. One thing that this baby could be thinking about, that could going on in 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 all of us to do is to figure out what people are thinking and feeling. And maybe the hardest thing of all to figure out that what other people think and isn’t actually exactly like what we think and feel. who’s followed politics can testify to how hard that is for some people to get. We wanted know if babies and young children could understand this really profound thing about people. Now the question is: How could we ask them? Babies, after all, can’t talk, and if ask a three year-old to tell you what he thinks, what you’ll get a beautiful stream of consciousness monologue about ponies and and things like that. So how do we actually ask them the question?
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Well it out that the secret was broccoli. What we did — Betty Rapacholi, who was one of my students, and — was actually to give the babies two bowls food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, like the crackers don’t like the raw broccoli. (Laughter) But then what Betty was to take a little taste of food from bowl. And she would act as if she liked 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 other person. But half the time, what she would do is take a little of the broccoli and go, “Mmmmm, broccoli. I tasted 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 she 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 is: What would the baby give her, what they liked or she liked? And the remarkable thing was that 18 month-old babies, barely walking and talking, would give her the crackers she liked the crackers, but they would give her the broccoli if she liked the broccoli. On other hand, 15 month-olds would stare at her for long time if she acted as if she liked broccoli, like they couldn’t figure this out. But then they stared for a long time, they would just give her the crackers, what they thought must like. So there are two really remarkable things this. The first one is that these little 18 month-old babies have discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, felt that they should actually do things to help other people get 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 about human nature the three months from when they were 15 months old. So children both know and learn more than we ever would have thought. this is just one of hundreds and hundreds of studies over last 20 years that’s actually demonstrated it.
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The question you might ask though is: Why children learn so much? And how is it possible for them to learn much in such a short time? I mean, after all, if you at babies superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, because 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 useless babies, it out that there’s actually an answer. If we look many, many different species of animals, not just us primates, also including other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s a relationship how long a childhood a species has and how big their brains are to their bodies and how smart and flexible they are.
And sort of the for this idea are the birds up there. On side is a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as smart as chimpanzees in some respects. this is a bird on the cover of science who’s learned 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 good 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. depend on their moms to drop worms in their open mouths for as long as two years, which a really long time in the life of a bird. Whereas the chickens are actually mature within couple of months. So childhood is the reason why the crows up on the cover of Science and the chickens end up in the soup pot.
There’s something about long childhood that seems to be connected to knowledge and learning. Well what kind of explanation could have for this? Well some animals, like the chicken, to be beautifully suited to doing just one thing very well. So seem to be beautifully suited to pecking grain in one environment. Other creatures, the crows, aren’t very good at doing anything in particular, but they’re extremely good at about laws of different environments.
And of course, we human beings are way out on the end of distribution like the crows. We have bigger brains relative to our bodies by far than any animal. We’re smarter, we’re more flexible, we can learn more, we survive in more different environments, we migrated cover the world and even go to outer space. And our babies and children are on us for much longer than the babies of any other species. My son 23. (Laughter) And at least until they’re 23, we’re still popping those worms into those little 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 one big disadvantage. And that one big disadvantage is that, until you do all that learning, you’re going to be helpless. So you don’t to have the mastodon charging at you and be saying to yourself, “A or maybe a spear might work. Which would actually better?” You want to know all that before the mastodons show up. And the way the evolutions seems to have that problem is with a kind of division of labor. So the idea that we have this 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 take all those things that we learned when we were babies and children and put them to work to do things out there in world.
So one way of thinking about it is that babies and young children are like research and development division of the human species. So they’re protected blue sky guys who just have to go 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 to use. Another of thinking about it is instead of thinking of and children as being like defective grownups, we should about them as being a different developmental stage of the species — kind of like caterpillars and butterflies — that they’re actually the brilliant butterflies who are flitting around garden and exploring, and we’re the caterpillars who are along our narrow, grownup, adult path.
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If is true, if these babies are designed to learn — and this evolutionary story would say children are learning, that’s what they’re for — we might expect that would have really powerful learning mechanisms. And in fact, the baby’s brain seems to be the most powerful computer on the planet. But real computers are actually getting to be lot better. And there’s been a revolution in our 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 did was to provide a mathematical way using probability theory to characterize, describe, the way scientists find out about the world. So what scientists is they have a hypothesis that they think might be likely to with. They go out and test it against the evidence. The evidence makes them change that hypothesis. Then test that new hypothesis and so on and so forth. what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of the best learning programs that we have now. And some 10 years ago, suggested that babies might be doing the same thing.
So if you want to know what’s going on underneath beautiful brown eyes, I think it actually looks something like this. This is Reverend Bayes’s notebook. I think those babies are actually making complicated calculations conditional probabilities that they’re revising to figure out how the world works. right, now that might seem like an even taller order to actually demonstrate. Because after all, you ask 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 up and plays when you put some things on it and not others. And using this very machine, my lab 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. If I showed you this detector, you be likely to think to begin with that the way to make the detector go be to put a block on top of the detector. But actually, this detector 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 detector actually activate two out of three times. Whereas, if you the likely thing, put the block on the detector, it will activate two out of six times. So the unlikely hypothesis has stronger evidence. It looks as if the waving is a more effective strategy than other strategy. So we did just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And enough, the four year-olds used the evidence to wave the object on top of the detector.
Now are two things that are really interesting about this. The one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these quite calculations that will give them a conditional probability measure. And the other interesting thing is that they’re that evidence to get to an idea, get to a about the world, that 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 at finding an unlikely hypothesis than adults are when we give exactly the same task. So in these circumstances, the children are using statistics to out about the world, but after all, scientists also do experiments, and wanted to see if children are doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of studies recently that have shown this playing around is a kind of experimental research program. Here’s one from Legare’s lab. What Cristine did was use our Blicket Detectors. And what did was show children that yellow ones made it and red ones didn’t, and then she showed them anomaly. And what you’ll see is that this little boy will go five hypotheses in the space of two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has just been falsified.
(Laughter)
Boy: This lighted up, and this one nothing.
AG: Okay, he’s got his experimental out.
Boy: What’s making 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 the experimenter to do this, to try putting it 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 here, but this 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 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 a particularly adorable and little boy, but what Cristine discovered is this is actually quite typical. If look at the way children play, when you ask to explain something, what they really do is do series of experiments. This is actually pretty typical of year-olds.
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Well, what’s it like to be this kind of creature? What’s it like to one of these brilliant butterflies who can test five in two minutes? Well, if you go back to those psychologists and philosophers, a lot them have said that babies and young children were conscious if they were conscious at all. And I just the opposite is true. I think babies and children are actually more conscious than we are adults. Now here’s what we know about how adult works. And adults’ attention and consciousness look kind of like spotlight. So what happens for adults is we decide that something’s relevant important, we should pay attention to it. Our consciousness of thing that we’re attending to becomes extremely bright and vivid, and everything else of goes dark. And we even know something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, the sort executive part of our brains, sends a signal 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 we at babies and young children, we see something very different. I think babies and young children seem to more of a lantern of consciousness than a spotlight of consciousness. So babies young children are very bad at narrowing down to just one thing. they’re very good at taking in lots of information from of different sources at once. And if you actually in their brains, you see that they’re flooded with these that are really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say that and young children are bad at paying attention, what really mean is that they’re bad at not paying attention. So they’re bad getting rid of all the interesting things that could tell them something just looking at the thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from those butterflies who are to learn.
Well if we want to think about a of getting a taste of that kind 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 in before — when we fall in love with someone new, or we’re in a new city for the first time. And what happens then is that our consciousness contracts, it expands, so that those three days in Paris seem be more full of consciousness and experience than all 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 the effect those baby neurotransmitters. So what’s it like to be a baby? It’s like being in love in for the first 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 be a grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that we put a lot of effort into babies think like adults do. But if what we want is to be like butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of time we should be getting the adults to start thinking more children.
(Applause)