What is going on this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, would have that this baby was irrational, illogical, egocentric — that couldn’t take the perspective of another person or understand and effect. In the last 20 years, developmental science has overturned that picture. So in some ways, we think this baby’s thinking is like the thinking of the brilliant scientists.
Let me give you just one example this. One thing that this baby could be thinking about, that could be going in his mind, is trying to figure out what’s going on the mind of that other baby. After all, one of the that’s hardest for all of us to do is to figure what other people are thinking and feeling. And maybe the hardest thing of all is to figure out what other people think and feel isn’t actually exactly like what we and feel. Anyone who’s followed politics can testify to how hard is for some people to get. We wanted to know if babies and young children could understand really profound thing about other people. Now the question is: could we ask them? Babies, after all, can’t talk, and 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 that. So how do we actually ask them the question?
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Well it turns that the secret was broccoli. What we did — Betty Rapacholi, who was one of students, and I — was actually to give the two bowls of food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, 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 would act as if she liked or she didn’t. So half the time, she acted as if she liked crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what she would is take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then would take 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 she was just the opposite of what the babies wanted. We did with 15 and 18 month-old babies. And then she would simply put her hand and say, “Can you give me some?”
So the is: What would the baby give her, what they liked or what she liked? And the remarkable thing that 18 month-old babies, just barely walking and talking, would give her the crackers she liked the crackers, but they would give her the broccoli if she the broccoli. On the other 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 stared for a long time, they just give her the crackers, what they thought everybody must like. So there two really remarkable things about this. The first one is that little 18 month-old babies have already discovered this really profound fact human nature, that we don’t always want the same thing. what’s more, they felt that they should actually do things to help people get what they wanted.
Even more remarkably though, fact that 15 month-olds didn’t do this suggests that these 18 month-olds had this deep, profound fact about human nature in the three months from when were 15 months old. So children both know more learn more than we ever would have thought. And 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 ask though is: Why do children learn so much? And how is it possible for them to so much in such a short time? I mean, after all, if you look babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to put so time and energy into just keeping them alive. But if we turn to evolution for answer to this puzzle of why we spend so time taking care of useless babies, it turns out there’s actually an answer. If we look across many, many different of animals, not just us primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, turns out that there’s a relationship between how long childhood a species has and how big their brains are compared to bodies and how smart and flexible they are.
And sort of posterbirds for this idea 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 smart as 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 dumps. So they’re very, very good at pecking for grain, and they’re much good at doing anything else. Well it turns that the babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little mouths for as long as two years, which is a really long in the life of a bird. Whereas the chickens actually mature within a couple of months. So childhood is reason why the crows end up on the cover of Science and chickens end up in the soup pot.
There’s something that long childhood that seems to be connected to and learning. Well what kind of explanation could we for this? Well some animals, like the chicken, seem to be beautifully suited 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 particular, but they’re extremely good at learning about laws of different environments.
And course, we human beings are way out on the end of the like the crows. We have bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated cover the world and even go to outer space. And babies and children are dependent on us for much than the babies of any other species. My son 23. (Laughter) And at least until they’re 23, we’re still those worms into those little open mouths.
All right, why would we this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in world, but it has one big disadvantage. And that one big is that, until you actually do all that learning, you’re to be helpless. So you don’t want to have the mastodon charging you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” You want to know that before the mastodons actually show up. And the way the evolutions seems to have solved that problem with a kind of division of labor. So the idea is that have this early period when we’re completely protected. We don’t have to do anything. All we have to is learn. And then as adults, we can take all things that we learned when we were babies and children and actually put them to work to things out there in the world.
So one way of thinking about it is that babies young children are like the research and development division of human species. So they’re the protected blue sky guys who just have to go out learn and have good ideas, and we’re production and marketing. We have to take all ideas that we learned when we were children and actually put them to use. Another way of thinking it is instead of thinking of babies and children as being like defective grownups, should think about them as being a different developmental of the same species — kind 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 narrow, grownup, adult path.
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If this is true, if babies are designed to learn — and this evolutionary story say children are for 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 be the most powerful learning computer on the planet. But real computers are actually getting to a lot better. And there’s been a revolution in our understanding of machine learning recently. And all depends on the ideas of this guy, the Thomas 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 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 evidence them change that hypothesis. Then they test that new hypothesis and on and so forth. And what Bayes showed was a mathematical that you could do that. And that mathematics is at the of the best machine learning programs that we have now. And 10 years ago, I suggested that babies might be doing the same thing.
So if you to know what’s going on underneath those beautiful brown eyes, I think actually looks something like this. This is Reverend Bayes’s notebook. I think those babies are actually making complicated calculations with probabilities that they’re revising to figure out how the world works. All right, now that might like an even taller order to actually demonstrate. Because after all, if ask even grownups about statistics, they look extremely stupid. could it be that children are doing statistics?
So to test this we used a machine that have called the Blicket Detector. This is a box lights up and plays music when you put some things on it and not others. And using this simple machine, my lab and others have done dozens of studies just how good 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 would likely to think to begin with that the way to make the detector would be to put a block on top of detector. But actually, this detector works in a bit of strange way. Because if you wave a block over the of the detector, something you wouldn’t ever think of to begin with, detector will actually activate two out of three times. Whereas, if you do the likely thing, put the block the detector, it will only activate two out of six times. So the unlikely hypothesis actually stronger evidence. It looks as if the waving is a more effective strategy than the strategy. So we did just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And sure enough, the four year-olds used the evidence wave the object on top of the detector.
Now there two things that are really interesting about this. The one is, again, remember, these 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 probability measure. And the other interesting is that they’re using that evidence to get to idea, get to a hypothesis about the world, that seems unlikely to begin with. And in studies we’ve just doing in my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than are when we give them exactly the same task. So these circumstances, the children are using statistics to find out the world, but after all, scientists also do experiments, and we wanted see if children are doing experiments. When children do experiments we call “getting into everything” or else “playing.”
And there’s been bunch of interesting studies recently that have shown this playing around is really a of 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 and ones didn’t, and then she showed them an anomaly. And what you’ll see is this little boy will go through five hypotheses in the of two minutes.
(Video) Boy: How about this? Same as the other side.
Alison Gopnik: Okay, his first hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this light up. (Laughter) don’t know.
AG: Every scientist will 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: this is his next idea. He told the experimenter 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, 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 make it light up and two on this one to it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — that is particularly adorable and articulate little boy, but what Cristine discovered this is actually quite typical. If you look at the way play, when you ask them to explain something, what they really do is do a 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 to be one of brilliant butterflies who can test five hypotheses in two minutes? Well, if you back to those psychologists and philosophers, a lot of them have that babies and young children were barely conscious if they were conscious at all. And I think the opposite is true. I think babies and children actually more conscious than we are as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind of like a spotlight. So what happens for is we decide that something’s relevant or important, we should attention to it. Our consciousness of that thing that we’re attending to becomes bright and vivid, and everything else sort of goes dark. we even know something about the way the brain this.
So what happens when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a signal makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in all the rest of brains. So we have a very focused, purpose-driven kind of attention. If we look at babies and children, we see something very different. I think babies young children seem to have more of a lantern consciousness than a spotlight of consciousness. So babies and young are very bad at narrowing down to just one thing. they’re very good at taking in lots of information lots of different sources at once. And if you actually look their brains, you see that they’re flooded with these neurotransmitters that are really good at learning and plasticity, and the inhibitory parts haven’t come on yet. So when we say babies and young children are bad at paying attention, what really 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 thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from those who are designed to learn.
Well if we want think about a way of getting a taste of kind of baby consciousness as adults, I think the best thing is think cases where we’re put in a new situation that we’ve never in before — when we fall in love with new, or when we’re in a new city for first time. And what happens then is not 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 you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it to be a baby? It’s like being in love in Paris 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 good to be a grownup. I don’t to say too much about how wonderful babies are. It’s to be a grownup. We can do things like tie our shoelaces and cross street by ourselves. And it makes sense that we a lot of effort into making babies think like adults do. But if we want is to be like those butterflies, to 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)