What is going in this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, would said that this baby was irrational, illogical, egocentric — that he couldn’t take 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 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 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 thinking 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 think and feel. Anyone who’s followed politics can testify to hard that is for some people to get. We wanted to know babies and young children could understand this really profound thing about other people. Now the question is: 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 about ponies and birthdays and things that. So 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 of my students, and I — was actually to the babies two bowls of food: one bowl of raw broccoli one bowl of delicious 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 it or she didn’t. So half the time, she as if she liked the crackers and didn’t like the — just like a baby and any other sane person. But half time, what she would do is take a little bit of the and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” then she 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 wanted was just the of what the babies wanted. We did this with 15 and 18 month-old babies. And then she simply put her hand out and say, “Can you give 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 crackers, but they would give her the broccoli if she liked broccoli. On the other hand, 15 month-olds would stare at her for a long time if she as if she liked the broccoli, like they couldn’t figure out. But then after they stared for a long time, they would just her the crackers, what they thought everybody must like. So are two really remarkable things about this. The first is that these little 18 month-old babies have already 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 to other people get what they wanted.
Even more remarkably though, fact that 15 month-olds didn’t do this suggests that these 18 month-olds learned this deep, profound fact about human nature in the three months from when were 15 months old. So children both know more and learn more than we ever would have thought. this is just one of hundreds and hundreds of studies over the 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 for them to learn so much in such a short time? mean, after all, if you look at babies superficially, they seem pretty useless. And actually many ways, they’re worse than useless, because we have put so much time and energy into just keeping them alive. if we turn to evolution for an answer to this puzzle of why we so much time taking care of useless babies, it turns out that there’s an answer. If we look across many, many different species of animals, not just us primates, but including other mammals, birds, even marsupials like kangaroos and wombats, it turns out there’s a relationship between how long a childhood a has and how big their brains are compared to bodies and how smart and flexible they are.
And sort of the 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 smart birds. They’re as smart as chimpanzees in some respects. And this a bird on the cover of science who’s learned how to use a tool get food. On the other hand, we have our friend the domestic chicken. And chickens and ducks geese and turkeys are basically as dumb as dumps. 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 depend on moms to drop worms in their little open mouths for as long as years, which is a really long time in the life of a bird. Whereas the 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 to be connected to knowledge and learning. Well what of explanation could we have for this? Well some animals, like the chicken, seem to beautifully suited to doing just one thing very well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t very good at doing anything particular, but they’re extremely good at learning about laws of environments.
And of course, we human beings are way out the end of the distribution like the crows. We have bigger brains relative to bodies by 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 and even to outer space. And our babies and children are on us for much longer than the babies of any species. My 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 this correlation? Well idea is that that strategy, that learning strategy, is extremely powerful, great strategy for getting on in the world, it has one big disadvantage. And that one big disadvantage is that, until you actually do all learning, you’re going to be helpless. So you don’t want to have the mastodon charging at you be saying to yourself, “A slingshot or maybe a might work. Which would actually be better?” You want to know all before the mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind of division of labor. the idea is that we have this early period when we’re protected. We don’t have to do anything. All we have do is learn. And then as adults, we can take all those things that we learned we were babies and children and actually put them to work do things out there in the world.
So one way of thinking it is that babies and young children are like the research and division of the human species. So they’re the protected blue sky who just have to go out and learn and have 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 thinking about it is instead of thinking of babies and children as being like grownups, we should think about them as being a different developmental of the same species — kind of like caterpillars butterflies — except that they’re actually the brilliant butterflies who are flitting around garden and exploring, and we’re the caterpillars who are inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to — and this evolutionary story would say children are learning, that’s what they’re for — we might expect that they would have really learning mechanisms. And in fact, the baby’s brain seems to the most powerful learning computer on the planet. But real are actually getting to be a lot 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 statistician and mathematician in the 18th century. And essentially what did was to provide a mathematical way using probability theory to characterize, describe, the that scientists find out about the world. So what do is they have a hypothesis that they think be likely to start with. They go out and test it against the evidence. The evidence makes change that hypothesis. Then they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way that you could do that. And that is at the core of the best machine learning programs that have now. And some 10 years ago, I suggested that babies might be doing the same thing.
So you want to know what’s going on underneath those beautiful eyes, I think it actually looks something like this. This is Reverend Bayes’s notebook. So think those babies are actually making complicated calculations with conditional 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, you ask even grownups about statistics, they look extremely stupid. could it be that children are doing statistics?
So to this we used a machine that we have called Blicket Detector. This is a box that lights up and plays music when you some things on it and not others. And using this very simple machine, 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 this detector, you would be likely to think to begin with that way to make the detector go would be to put a block on top the detector. But actually, this detector works in a of a strange way. Because if you wave a over the top of the 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 unlikely hypothesis actually has stronger evidence. It looks as if the waving is a more effective than the other strategy. So we did just this; gave four year-olds this pattern of evidence, and we asked them to make it go. And sure enough, four year-olds used the evidence to wave the object on top the detector.
Now there are two things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning how count. But unconsciously, they’re doing these quite complicated calculations that will them a conditional probability measure. And the other interesting thing that 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 out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, the children are statistics to find out about the world, but after all, also do experiments, and we wanted to see if children are experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of interesting studies recently that have this playing around is really a kind of experimental program. Here’s one from Cristine Legare’s lab. What Cristine did was our Blicket Detectors. And what she did was show children yellow ones made it go and red ones didn’t, then she showed them an anomaly. And what you’ll is that this little boy will go through five in the 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, and this one nothing.
AG: Okay, he’s got experimental notebook 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 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, because the goes only to here, not here. Oh, the bottom of box has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s a hypothesis.
Boy: It’s lighting up. So when you put four. So you put four on this one to it light up and two on this one to 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 at the way children play, when you ask them 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 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 philosophers, a lot of them have said that babies young children were barely conscious if they were conscious at all. And I think just the opposite true. I think babies and children are actually more than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens for is we decide that something’s relevant or important, we should pay attention to it. Our consciousness of thing that we’re attending to becomes extremely bright and vivid, and everything sort of goes dark. And we even know something about way the brain does this.
So what happens when we pay attention is that prefrontal cortex, the sort of executive part of our brains, a signal that makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in all the rest our 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 children are very bad at narrowing down to just one thing. But they’re very good at taking in of information from lots of different sources at once. And if you actually look in their brains, 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 that babies and children are bad at paying attention, what we really mean is that they’re bad not paying attention. So they’re bad at getting rid of the interesting things that could tell them something and just looking at the that’s important. That’s the kind of attention, the kind of consciousness, that might expect from those butterflies who are designed to learn.
Well if we to think about a way of getting a taste of that kind of baby consciousness as adults, think the best thing is think about cases where we’re 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 is not that consciousness contracts, it expands, so that those three days in Paris seem be more full of consciousness and experience than all the of being a walking, talking, faculty meeting-attending zombie back home. And by the way, that coffee, wonderful coffee you’ve been drinking downstairs, actually mimics the of those baby neurotransmitters. So what’s it like to a baby? It’s like being in love in Paris for first time after you’ve had three double-espressos. (Laughter) That’s fantastic way to be, but it does tend to leave you waking up crying at o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want to say too 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. 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 those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults start thinking more like children.
(Applause)