What is going in this baby’s mind? If you’d asked people this 30 years ago, most people, psychologists, would have said that this baby was irrational, illogical, — that he couldn’t take the perspective of another or understand cause and effect. In the last 20 years, developmental has completely overturned that picture. So in some ways, we think that this baby’s is like the thinking of the most brilliant scientists.
Let me give you one example of this. One thing that this baby be thinking about, that could be going on in his mind, is trying to figure out what’s on in the mind of that other baby. After all, one the things that’s hardest for all of us to do is to figure out what other people are and feeling. And maybe the hardest thing of all is to figure out that other people think and feel isn’t actually exactly like what we think and feel. who’s followed politics can testify to how hard that is for some people get. We wanted to know if babies and young children could this really profound thing about other people. Now the question is: How could ask them? Babies, after all, can’t talk, and if you ask a three year-old to tell you he thinks, what you’ll get is a beautiful stream of consciousness monologue about ponies and and things like that. So how do we actually them the question?
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Well it turns out that the secret broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give babies two bowls of food: one bowl of raw broccoli and bowl of delicious goldfish crackers. Now all of the babies, in Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But then what did was to take a little taste of food each bowl. And she would act as if she liked or she didn’t. So half the time, she acted as if liked the crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what she would do take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would a little bit of the 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: What the baby 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 broccoli she liked 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, like they couldn’t figure this out. But then after 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. first one is that these little 18 month-old babies have already discovered really profound fact about human nature, that we don’t always want the same thing. And what’s more, felt that they should actually do things to 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 this deep, fact about human nature in the three months from when they were 15 months old. So both know more and 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 might ask is: Why do children learn so much? And how is it possible for them to learn so in such a short time? I mean, after all, if you look at babies superficially, they 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 to this puzzle why we spend so much time taking care of babies, it turns out that there’s actually an answer. If look across many, many different species of animals, not just primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, turns out that there’s a relationship between how long a childhood a species has and how 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 New Caledonian crow. crows and other corvidae, ravens, rooks and so forth, incredibly smart birds. They’re as smart as chimpanzees in some respects. And is a bird on the cover of science who’s learned how to a tool to get food. On the other hand, we have our friend the chicken. And chickens and ducks and geese and turkeys are as dumb as dumps. So they’re very, very good pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, the Caledonian crow babies, are fledglings. They depend on their to drop worms in their little open mouths for as long as two years, which a really long time in the life of a bird. the chickens are actually mature within a couple of months. So childhood is reason why the crows end up on the cover of Science and the chickens end up the soup pot.
There’s something about that long childhood that seems to be to knowledge and learning. Well what kind of explanation could have for this? Well some animals, like the 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 anything in particular, but they’re extremely good at learning laws of different environments.
And of course, we human are way out on the end of the distribution the crows. We have bigger brains relative to our bodies by far any other animal. We’re smarter, we’re more flexible, we can learn more, we survive in more environments, we migrated to cover the world and even go to outer space. And our and children are dependent on us for much longer than the babies of any other species. son is 23. (Laughter) And at least until they’re 23, we’re still popping worms into those little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in the world, but it one big disadvantage. And 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 or maybe a spear work. Which would actually be better?” You want to know that before the mastodons actually show up. And the way evolutions seems to have solved that problem is with a kind 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 we have to do learn. And then as adults, we can take all those that we learned when we were babies and children and put them to work to do things out there in the world.
So one of thinking about it is that babies and young are like the research and development division of the human species. they’re the protected blue sky guys who just have to go out learn and have good ideas, and we’re production and marketing. have to take all those ideas that we learned when we children and actually put them to use. Another way of thinking about it is instead of thinking 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 are flitting around the garden and exploring, and we’re caterpillars who are inching along our narrow, grownup, adult path.
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If this true, if these babies are designed to learn — this evolutionary story would say children are for learning, that’s what they’re for — we might expect that they have really powerful learning mechanisms. And in fact, the baby’s brain seems to be the most powerful learning computer the planet. But real computers are actually getting to be a better. And there’s been a revolution in our understanding of machine learning recently. it all depends on 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 find out about the world. So what scientists do they have a hypothesis that they think might be to start with. They go out and test it against the evidence. evidence makes them change that hypothesis. Then they test that new hypothesis and on and so forth. And what Bayes showed was a mathematical way you could do that. And that mathematics is at the core of the machine learning programs that we have now. And some 10 years ago, I suggested that babies might be the same thing.
So if you want to know what’s going underneath those beautiful brown eyes, I think it actually looks something this. This is Reverend Bayes’s notebook. So I think those babies are actually 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 order to actually demonstrate. Because after all, you ask even grownups about statistics, they look extremely stupid. How it be that children are doing statistics?
So to test this we used a machine we have called the Blicket Detector. This is a that lights up and plays music when you put things on it and not others. And using this simple machine, my lab and others have done dozens of studies showing how good babies are at learning about the world. Let me 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 to make the detector go would be to put a block top of the detector. But actually, this detector works a bit of a strange way. Because if you wave a block the top of the detector, something you wouldn’t ever think to begin with, the detector will actually activate two of three times. Whereas, if you do the likely thing, put the on the detector, it will only activate two out of six times. the unlikely hypothesis actually has stronger evidence. It looks as if the is a more effective strategy than the other strategy. So we did just this; gave four year-olds this pattern of evidence, and we just asked to make it go. And sure enough, the four year-olds the evidence to 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 how to count. But unconsciously, they’re doing these quite calculations that will give them a conditional probability measure. And the interesting thing is that they’re using that evidence to get to an idea, get to a about the world, that seems very unlikely to begin with. in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better at finding out an unlikely hypothesis than are when we give them exactly the same task. So in these circumstances, the children using statistics to find out about the world, but after all, also do experiments, and we wanted to see if are doing experiments. When children do experiments we call “getting into everything” or else “playing.”
And there’s been a of interesting studies recently that have shown this playing around is really a kind of experimental program. Here’s one from Cristine Legare’s lab. What Cristine did use our Blicket Detectors. And what she did was children that yellow ones made it go and red didn’t, and then she showed them an anomaly. And what you’ll see is that this little will go through five hypotheses in the space of two minutes.
(Video) Boy: How about this? Same the other side.
Alison Gopnik: Okay, so his first hypothesis has just falsified.
(Laughter)
Boy: This one lighted up, and this one nothing.
AG: Okay, he’s his experimental notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every scientist recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to be this, and this needs to be like this.
AG: Okay, 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, the light goes only to here, not here. Oh, the bottom of this box has electricity in here, this doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So when you four. So you put four on this one to make it light up two on this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — is a particularly adorable and articulate little boy, but what discovered is this is actually quite typical. If you look at way children play, when you ask them to explain something, what they really do do a series of experiments. This is actually pretty of four year-olds.
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Well, what’s it like to be this kind of creature? What’s it to be one of these brilliant butterflies who can five hypotheses in two minutes? Well, if you go back to those psychologists and philosophers, a lot of have said that babies and young children were barely conscious if they were conscious at all. And think just the opposite is true. I think babies children are actually more conscious than we are as adults. Now here’s what know about how adult 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. consciousness of that 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 that the prefrontal cortex, the sort of executive part of our brains, sends a signal that 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 we have very focused, purpose-driven kind of attention. If we look at babies and young children, we something very different. I think babies and young children seem to have more a lantern of consciousness than a spotlight of consciousness. So babies and children are very bad at narrowing down to just thing. But they’re very good at taking in lots of information from 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 learning and plasticity, the inhibitory parts haven’t come on yet. So when we say that babies and young children are bad paying attention, what we really mean is that they’re bad not paying attention. So they’re bad at getting rid all the interesting things that could tell them something and just looking at the thing that’s important. That’s kind of attention, the kind of consciousness, that we might expect those butterflies who are designed to learn.
Well if want to think about a way of getting a taste of that kind baby consciousness as adults, I think the best thing think about cases where we’re put in a new that we’ve never been 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, expands, so that those three days in Paris seem to more full of consciousness and experience than all the months of a walking, talking, faculty meeting-attending zombie back home. And the way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics effect of those baby neurotransmitters. So what’s it like be a baby? It’s like being in love in Paris for the time after you’ve had three double-espressos. (Laughter) That’s a way to be, but it does tend to leave you waking up at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say too much about how babies are. It’s good to be a grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that we put a of effort into making babies think like adults do. But if what we want is be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of the time we be getting the adults to start thinking more like children.
(Applause)