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 this baby was irrational, illogical, — that he couldn’t take the perspective of another person or understand cause and effect. the last 20 years, developmental science has completely overturned picture. So in some ways, we think that this baby’s thinking is the thinking of the most brilliant scientists.
Let me give you just one example of this. One thing this baby could be thinking about, that could be on 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 out what other people are thinking and feeling. And the hardest thing of all is to figure out that what other think and feel isn’t actually exactly like what we think and feel. Anyone who’s followed politics can testify how hard that is for some people to get. We to know if babies and young children could understand really profound thing about other people. Now the question is: How could ask them? Babies, after all, can’t talk, and if you ask three year-old to tell you what he thinks, what you’ll get is a beautiful stream consciousness monologue about ponies and birthdays and things like that. how do we actually ask them the question?
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Well it turns out that the was broccoli. What we did — Betty Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take a little taste of food from each bowl. she would 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 — like a baby and any other sane person. But half the time, what she would do is a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d as if what she wanted was just the opposite of the babies wanted. We did this with 15 and 18 month-old babies. And then she would simply her hand out and say, “Can you give me some?”
So the question is: What would the baby her, what they liked or what she liked? And 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. the other hand, 15 month-olds would stare at her a long time if she acted as if she liked broccoli, like they couldn’t figure this out. But then after they stared for long time, they would just give her the crackers, what they thought everybody like. So there are two really remarkable things about this. first one is that these little 18 month-old babies already discovered this really profound fact about human nature, that we don’t always want the same thing. 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 that these 18 month-olds had learned deep, profound fact about human nature in the three months when they were 15 months old. So children both know and learn more than we ever would have thought. And this is just one of hundreds and of studies over the last 20 years that’s actually demonstrated it.
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The question might ask though is: Why do children learn so much? And is it possible for them to learn so much such a short time? I mean, after all, if you look at babies superficially, they seem useless. And actually in many ways, they’re worse than useless, because we have to so much time and energy into just keeping them alive. But if we turn to evolution an 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 species 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 a a species has and how big their brains are compared to their bodies and how smart and they are.
And sort of the posterbirds for this are the birds up there. On one side is a Caledonian 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 cover of science who’s learned to use a tool to get food. On the other hand, have our friend the domestic chicken. And chickens and ducks and geese turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much good doing anything else. Well it turns out that the babies, New Caledonian crow babies, are fledglings. They depend on their moms to drop worms their little open mouths for as long as two years, is a really long time in the life of 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 and the chickens end up in the soup pot.
There’s about that long childhood that seems to be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, like the chicken, seem be beautifully suited to doing just one thing very well. they seem to be beautifully suited to pecking grain 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 of course, we human beings are out on the end of the distribution like the crows. We have bigger brains relative to our bodies far than any other animal. We’re smarter, we’re more flexible, can learn 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 for longer than the babies of any other species. My is 23. (Laughter) And at least until they’re 23, we’re still popping those worms into those open mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, is an powerful, great strategy for getting on in the world, but it has one big disadvantage. And one big disadvantage is that, until you actually do all that learning, you’re going to helpless. So you don’t want to have the mastodon charging at you and be saying yourself, “A slingshot or maybe a spear might work. Which actually be better?” You want to know all that before the actually show up. And the way 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 have 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 do things out in the world.
So one way of thinking about is that babies and young children are like the research development division of the human species. So they’re the protected blue sky guys who have to go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas that we when we were children and actually put them to use. Another way of thinking about is instead of thinking of babies 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 — except that they’re actually the brilliant butterflies who are around the garden and exploring, and we’re the caterpillars who are inching along narrow, grownup, adult path.
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If this is true, these babies are designed to learn — and this evolutionary story say children are for learning, that’s what they’re for — we might expect that they would have powerful learning mechanisms. And in fact, the baby’s brain seems to be the most learning computer on the planet. But real computers are actually getting be a lot better. And there’s been a revolution in understanding of machine learning recently. And it all depends the ideas of this guy, the Reverend Thomas Bayes, was a statistician and mathematician in the 18th century. essentially what Bayes did was to provide a mathematical using probability theory to characterize, describe, the way that scientists find about the world. So what scientists do is they have a hypothesis that think might be likely to start with. They go and test it against the evidence. The evidence makes them that hypothesis. Then they test that new hypothesis and on and so forth. And what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of the best machine programs that we have now. And some 10 years ago, suggested that babies might be doing the same thing.
So if want to know what’s going on underneath those beautiful brown eyes, I think it actually looks like this. This is Reverend Bayes’s notebook. So I think those are actually making complicated calculations with conditional probabilities that they’re revising to figure out how the world works. right, now that might seem like an even taller to actually demonstrate. Because after all, if you ask even about statistics, they look extremely stupid. How could it be children are doing statistics?
So to test this we used a machine that we called the Blicket Detector. This is a box that lights and plays music when you put some things on it and not others. And this very simple machine, my lab and others have done dozens of studies showing just good babies are at learning about the world. Let me mention just one 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 detector go would be to put a block on of the detector. But actually, this detector works in a bit a strange way. Because if you wave a block over the of the detector, something you wouldn’t ever think of to begin with, the will actually activate two out of three times. Whereas, if you do the thing, put the block on the detector, it will only activate out of six times. So the unlikely hypothesis actually has stronger evidence. It looks as if the is a more effective strategy than the other strategy. So we just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And sure enough, the year-olds used the evidence to wave the object on top of the detector.
Now there are two things are really interesting about this. The first one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these complicated calculations that will give them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, to a hypothesis about the world, that seems very unlikely to with. And in studies we’ve just been doing in lab, similar studies, we’ve show that four year-olds are actually better at finding out an unlikely hypothesis adults are when we give them exactly the same task. in these circumstances, the children are using statistics to find out about world, but after all, scientists also do experiments, and we wanted see if children are doing experiments. When children do experiments call it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown this playing around is really a kind of research program. Here’s one from Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. And what did was show children that yellow ones made it go and red ones didn’t, and then she showed 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 about this? as the other 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 notebook out.
Boy: What’s making light up. (Laughter) I don’t know.
AG: Every scientist will recognize that expression despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, this needs to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this his next idea. He told the experimenter to do this, to try putting it out onto the other location. working either.
Boy: Oh, because the light goes only here, not here. Oh, the bottom of this box has electricity here, but this doesn’t have electricity.
AG: Okay, that’s fourth hypothesis.
Boy: It’s lighting up. So when you put four. So you four on this one to make it light up and two this 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 them to explain something, what they really do is do a series of experiments. is actually pretty typical of four year-olds.
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Well, what’s it like to this kind of creature? What’s it like to be of these brilliant butterflies who can test five hypotheses two minutes? Well, if you go back to those psychologists philosophers, a lot of them have said that babies and young children were barely if they were conscious at all. And I think just the is true. I think babies and children are actually conscious than we are as adults. Now here’s what we know about adult consciousness works. And adults’ attention and consciousness look kind of like a spotlight. 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 sort of dark. And we even know something about the way the does this.
So what happens when we pay attention is that the prefrontal cortex, the sort of executive of our brains, sends a signal that makes a part of our brain much more flexible, more plastic, at learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven kind of attention. 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 than a spotlight of consciousness. So babies and young children 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 in their brains, you see they’re flooded with these neurotransmitters that are really good at inducing and plasticity, and the inhibitory parts haven’t come on yet. So we say that babies and young children are bad at paying attention, what we really is that they’re bad at not paying attention. So they’re bad at getting rid of all the things that could tell them something and just looking the thing that’s important. That’s the kind of attention, kind of consciousness, that we might expect from those butterflies who designed to learn.
Well if we want to think about way of getting a taste of that kind of consciousness as adults, I think the best thing is think about cases where we’re put in a situation that we’ve never been in before — when we fall love with someone new, or when we’re in a new for the first time. And what happens then is that our consciousness contracts, it expands, so that those days in Paris seem to be more full of consciousness and experience than 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, actually mimics the 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 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 want to too much about how wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street by ourselves. And it sense that we put a lot of effort into making babies think like do. But if what we want is to be like those butterflies, 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)