What is going on 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 the of another person or understand cause and effect. In the last 20 years, developmental science completely overturned that picture. So in some ways, we that this baby’s thinking is like the thinking of most brilliant scientists.
Let me give you just one example of this. 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 that’s hardest for all of us to do is figure out what other people are thinking and feeling. maybe the hardest thing of all is to figure out what other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can testify how hard that is for some people to get. We wanted to know babies and young children could understand this really profound thing about people. Now the question is: How could we ask them? Babies, after all, can’t talk, and if you a three year-old to tell you what he thinks, what you’ll get is a beautiful stream of monologue about ponies and birthdays and things like that. So how do we actually them the question?
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Well it turns out the secret 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 and one bowl of delicious goldfish crackers. Now all of the babies, even in Berkley, 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 would act as if she liked it or she didn’t. So half time, she acted as if she liked the crackers and didn’t the broccoli — just like a baby and any other person. But half the time, what she would do is take a bit of the broccoli and go, “Mmmmm, broccoli. I tasted broccoli. Mmmmm.” And then she would take a little bit the crackers, and she’d go, “Eww, yuck, crackers. I tasted crackers. Eww, yuck.” So she’d act as if what she wanted was just opposite of what the babies wanted. We did this 15 and 18 month-old babies. And then she would simply put her 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 the thing was that 18 month-old babies, just barely walking and talking, 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 the broccoli, like they couldn’t this out. But then after they stared for a long time, they would just give her the crackers, they thought everybody must like. So there are two remarkable things about this. The first one is that these little 18 month-old have already discovered this really profound fact about human nature, that we don’t always want the thing. And what’s more, they felt that they should actually do things to help people get what they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t this suggests that these 18 month-olds had learned this deep, profound fact human nature in the three months from when they 15 months old. So children both know more and more than we ever would have thought. And this just one of hundreds and hundreds of studies over the last 20 that’s actually demonstrated it.
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The question you ask though is: Why do children learn so much? how is it possible for them to learn so much such a short time? I mean, after all, if look at babies superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, we have to put so much time and energy into just keeping alive. But if we turn to evolution for an answer to this puzzle of why spend so much time taking care of useless babies, it out that there’s actually an answer. If we look many, many different species of animals, not just us primates, also including other mammals, birds, even marsupials like kangaroos wombats, it turns out that there’s a relationship between how a childhood a species has and how big their brains are compared to their bodies how smart and flexible they are.
And sort of the posterbirds for this idea are the up there. On one side is a New Caledonian crow. And and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart as chimpanzees some respects. And this is a bird on the of science who’s learned how to use a tool to 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 not much at doing anything else. Well it turns out that the babies, the New Caledonian crow babies, 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 a bird. Whereas the chickens are actually within 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 that seems to be connected to knowledge and learning. Well what of explanation could we have for this? Well some animals, like the chicken, to be beautifully suited to doing just one thing well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t good at doing anything in particular, but they’re extremely good at learning laws of different environments.
And of course, we human beings are way out on end of the distribution like the crows. We have bigger brains relative to our bodies by far than 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 babies and are dependent on us for much longer than the babies any other species. My son is 23. (Laughter) And least until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, is 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 all 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 maybe a spear might work. Which would actually be better?” You want to know all that before mastodons actually show up. And the way the evolutions to have solved that problem is with a kind division of labor. So the idea is that we this early period when we’re completely protected. We don’t have do anything. All we have to do is learn. then as adults, we can take all those things that we learned when we babies and children and actually put them to work to do things there in the world.
So one way of thinking about it is that babies young children are like the research and development division of the species. So they’re the protected blue sky guys who just to go out and learn and have good ideas, 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 of thinking about it is instead of thinking of babies and children as like defective grownups, we should think about them as being a different developmental of the same species — kind of like caterpillars and — except that they’re actually the brilliant butterflies who are flitting around the garden and exploring, and we’re 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 be the most 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 it all on the ideas of this guy, the Reverend Thomas Bayes, who was a statistician and in the 18th century. And essentially what Bayes did was to provide a mathematical way using theory to characterize, describe, the way that scientists find out the world. So what scientists do is they have a hypothesis that they might be likely to start with. They go out test it against the evidence. The evidence makes them change that hypothesis. Then they that new hypothesis and so on and so forth. And what Bayes showed was a mathematical that you could do that. And that mathematics is at the core of the best learning programs that we have now. And some 10 ago, I suggested that babies might be doing the same thing.
So you want to know what’s going on underneath those beautiful brown eyes, I think it looks something like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional that they’re revising to figure out how the world works. All right, that might seem like an even taller order to demonstrate. Because after all, if you ask even grownups 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 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 you this detector, would be likely to think to begin with that the way to make the go would be to put a block on top the detector. But actually, this detector works in a bit of strange way. Because if you wave a block over the top of detector, something you wouldn’t ever think of to begin with, the will actually activate two out of three times. Whereas, if you the likely 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 if the waving is a more effective strategy than other 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, the year-olds used the evidence to wave the object on of the detector.
Now there are two things that are really interesting about this. first one is, again, remember, these are four year-olds. They’re just learning to count. But unconsciously, they’re doing these quite complicated that will give them a conditional probability measure. And the other interesting is that they’re using that evidence to get to an idea, get to a hypothesis about the world, seems very unlikely to begin with. And in studies we’ve just been doing in my lab, similar studies, we’ve that four year-olds are actually better at finding out unlikely hypothesis than adults are when we give them exactly the same task. in these circumstances, the children are using statistics to find out about the world, but after all, scientists do experiments, and we wanted to see if children doing experiments. When children do experiments we call it “getting into everything” else “playing.”
And there’s been a bunch of interesting recently that have shown this playing around is really 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 an anomaly. And what you’ll see is that this boy will go through five hypotheses in the space two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis just been falsified.
(Laughter)
Boy: This one lighted up, and one 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 be like this, and this needs to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now is his next idea. He told the experimenter to do this, to try putting out onto the other location. Not working either.
Boy: Oh, 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 lighting up. So you put four. So you put four on this one to make light up and two on this one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is a particularly and articulate 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 in two minutes? Well, if you go back to those psychologists and philosophers, a lot them have said that babies and young children were barely conscious if were conscious at all. And I think just the opposite is true. I think babies and are actually more conscious than we are as adults. Now here’s what know about how adult consciousness works. And adults’ attention consciousness 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 that that we’re attending to becomes extremely bright and vivid, everything else sort of goes dark. And we even know something about the way brain does this.
So what happens when we pay attention that the prefrontal cortex, the sort of executive part our brains, sends a signal that makes a little part of brain much more flexible, more plastic, better at learning, and shuts down activity in the rest of 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 a lantern of consciousness than a spotlight of consciousness. So babies young children are 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 look in their brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and the inhibitory parts haven’t come yet. So when we say that babies and young children are bad at paying attention, we really mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting things that could them something and just looking at the thing that’s important. That’s the kind of attention, the of consciousness, that we might expect from those butterflies are designed to learn.
Well if we want to about a way of getting a taste of that of baby consciousness as adults, I think the best thing is think about cases where we’re in a new situation that we’ve never been in before — when fall in love with someone new, or when we’re in a new city for the time. And what happens then is not that our consciousness contracts, expands, so that those three 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 you’ve been drinking downstairs, actually mimics the effect of baby neurotransmitters. So what’s it like to be a baby? It’s being in love in Paris for the first 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 good to be a grownup. I don’t want say too much about how wonderful babies are. It’s to be a grownup. We can do things like tie our shoelaces and cross the by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But if we want is to be like those butterflies, to have open-mindedness, learning, imagination, creativity, innovation, maybe at least some of the time we should getting the adults to start thinking more like children.
(Applause)