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