What is on in this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, have said that 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 overturned that picture. So in some ways, we think this baby’s thinking is like the thinking of the most brilliant scientists.
Let me give you just one of 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 in the of that other baby. After all, one of the things that’s hardest for of us to do is to figure out what other 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 people to get. We wanted to know if babies and young children could understand this really thing about other people. Now 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, you’ll get is a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how do we ask them the question?
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Well it turns out that the secret was broccoli. we did — Betty Rapacholi, who was one of my students, and I — was actually to give babies two bowls of food: one bowl of raw and one bowl of delicious goldfish crackers. Now all the babies, even in Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But what Betty did was to take a little taste of from each bowl. And she would act as if she liked it or she didn’t. half the time, she acted as if she liked the and didn’t like the broccoli — just like a baby and any other sane person. But the time, what she would do is take a little bit of 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. tasted the crackers. Eww, yuck.” So she’d act as if what she wanted was the opposite of what the babies wanted. We did this 15 and 18 month-old babies. And then she would simply put her hand out and say, “Can you me some?”
So the question is: What would the give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just barely walking talking, would give her the crackers if she liked crackers, but they would give her the broccoli if liked the broccoli. On the other hand, 15 month-olds would at her for a long time if she acted as if liked the broccoli, like they couldn’t figure this out. But then they stared for a long time, they would just give her the crackers, they thought everybody must like. So there are two really things about this. The first one is that these 18 month-old babies have already discovered this really profound about human nature, that we don’t always want the same thing. And what’s more, they felt that should actually do things to help other people get they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t do suggests that these 18 month-olds had learned this deep, profound fact about nature in the three months from when they were 15 months old. So children both know more and learn than we ever would have thought. And this is just one of and hundreds of studies over the last 20 years that’s actually demonstrated it.
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question you might ask though is: Why do children learn so much? And how it possible for them to learn so much in such a short time? mean, after all, if you look at babies superficially, seem pretty useless. And actually in many ways, they’re than useless, because we have to put so much time and energy into just them alive. But if we turn to evolution for an answer to this of why we spend so much time taking care of useless babies, it turns that there’s actually an answer. If we look across many, different species of animals, not just us primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a relationship between how long a childhood a species and how big their brains are compared to their bodies and how smart flexible 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, are 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 domestic chicken. And and ducks and geese and turkeys are basically as dumb dumps. So they’re very, very good at pecking for grain, they’re not much good at doing anything else. Well it out that the babies, the New Caledonian crow babies, fledglings. They depend on their moms to drop worms in their little open mouths for long as two years, which is a really long time in the of a bird. Whereas the chickens are actually mature a couple of months. So childhood is the reason the crows end up on the cover of Science and chickens end up in the soup pot.
There’s something about that long childhood seems to be connected to knowledge and learning. Well what kind of could we have for this? Well some animals, like the chicken, to 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 doing anything in particular, but they’re extremely good at about laws of different environments.
And of course, we human beings are way out the end of the distribution like the crows. We have bigger brains relative our bodies by far than any other animal. We’re smarter, we’re flexible, we can learn more, we survive in more environments, we migrated to cover the world and even go outer space. And our babies and children are dependent on us for much longer the babies of any other species. My son is 23. (Laughter) And at 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, an extremely powerful, great strategy for getting on in the world, but has 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 mastodon charging at you and be saying to yourself, “A slingshot or maybe spear might work. Which would actually be better?” You to know all that before the mastodons actually show up. the way the evolutions seems to have solved that problem is with a kind of division labor. So the idea is that we have this 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 those things that we when we were babies and children and actually put them to work to things out there in the world.
So one way thinking about it is that babies and young children are like the research development division of the human species. So they’re the blue sky guys who just have to go out and and have good ideas, and we’re production and marketing. have to take all those ideas that we learned we were children and actually put them to use. way of thinking about it is instead of thinking of babies and as being like defective grownups, we should think about them as a different developmental stage of the same species — of like caterpillars and butterflies — except that they’re actually the butterflies who are flitting around the garden and exploring, and we’re the who are inching along our narrow, grownup, adult path.
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If this is true, if these babies are 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, baby’s brain seems to be the most powerful learning on the planet. But real computers are actually getting to be a better. And there’s been a revolution in our understanding machine learning recently. And it all depends on the of this guy, the Reverend Thomas Bayes, who was a statistician and mathematician in 18th century. And essentially what Bayes did was to provide a mathematical way using probability theory characterize, describe, the way that scientists find out about the world. So what do is they have a hypothesis that they think might likely to start with. They go out and test it 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 machine learning programs that we have now. And some 10 years ago, I suggested babies might be doing the same thing.
So if you want to know what’s on underneath those beautiful brown eyes, I think it actually looks something this. This is Reverend Bayes’s notebook. So I think babies are actually making complicated calculations with conditional probabilities that they’re revising to figure out how the works. All right, now that might seem like an even taller to actually demonstrate. Because after all, if you ask even grownups about statistics, they look extremely stupid. How it be that children are doing statistics?
So to test this we a machine that we have called the Blicket Detector. This a box that lights up and plays music when put some things on it and not others. And using this very machine, my lab and others have done dozens of 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 to begin with that the way to make the detector go would be to put block on top of the detector. But actually, this detector works in bit of a strange way. Because if you wave a block over the top of detector, something you wouldn’t ever think of to begin with, the detector will activate two out of three times. Whereas, if you do the likely thing, put the on the detector, it will only activate two out of six times. So the unlikely hypothesis actually has evidence. It looks as if the waving is a effective strategy than the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just asked to make it go. And sure enough, the four year-olds used evidence to wave the object on top of the detector.
Now there are two things that really interesting about this. The first one is, again, remember, are four year-olds. They’re just learning how to count. unconsciously, they’re doing these quite complicated calculations that will them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, get a hypothesis about the world, that seems very unlikely begin with. And in studies we’ve just been doing my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than adults when we give them exactly the same task. So these circumstances, the children are using statistics to find out about world, but after all, scientists also do experiments, and we wanted to see if children doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch interesting studies recently that have shown this playing around really a kind of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did was use Blicket Detectors. And what she did was show children that yellow ones made go and red ones didn’t, and then she showed them an anomaly. And what you’ll see that this little boy will go through five hypotheses in space of two minutes.
(Video) Boy: How about this? Same the other side.
Alison Gopnik: Okay, so his first has just been falsified.
(Laughter)
Boy: This one lighted up, 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 scientist will 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. told the experimenter to do this, to try putting it out 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 on this one to make it light up and two on this one to it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is 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 a series of experiments. This is pretty typical of four year-olds.
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Well, what’s it like to be this kind creature? What’s it like to be one of these brilliant butterflies can test five hypotheses in 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 know about how adult consciousness works. And adults’ attention and consciousness look kind like a spotlight. So what happens for adults is we decide that something’s relevant or important, should pay attention to it. Our consciousness of that that we’re attending to becomes extremely bright and vivid, everything else sort of goes dark. And we even something about the way the brain does this.
So happens when we pay attention is that the prefrontal cortex, the sort executive part of our brains, sends a signal that makes little part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven kind attention. If we look at babies and young children, we see something different. I think babies and young children seem to have more of a lantern of than a spotlight of consciousness. So babies and young children are very bad narrowing down to just one thing. But they’re very at taking in lots of information from lots of sources at once. And if you actually look in their brains, you see that they’re flooded with neurotransmitters that are really good at inducing learning and plasticity, the inhibitory parts haven’t come on yet. So when we say that 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 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 expect from those butterflies who are designed to learn.
Well if want to think about a way of getting a taste of that kind of baby as adults, I think the best thing is think about cases we’re put in a new situation that we’ve never been in before — when we fall love with someone new, or when we’re in a city for the first time. And what happens then not that our consciousness contracts, it expands, so that those three days in Paris to be more full of consciousness and experience than all the months of being walking, talking, faculty meeting-attending zombie back home. And by 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 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 to be a grownup. I don’t want to say much about how wonderful babies are. It’s good to be a grownup. We can do things like tie shoelaces and cross the street by ourselves. And it makes sense that put a lot of effort into making babies think adults do. But if what we want is to be like butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults to thinking more like children.
(Applause)