What going on in this baby’s mind? If you’d asked people 30 years ago, most people, including psychologists, would have said that this baby irrational, illogical, egocentric — that he couldn’t take the perspective of another person or understand cause and effect. the last 20 years, developmental science has completely overturned that picture. So in some ways, think that this baby’s thinking is like the thinking of the most scientists.
Let me give you just one example of this. One thing that baby could be thinking about, that could be going on in mind, is trying to figure out what’s going on the mind of that other baby. After all, one of the things that’s hardest for of us to do is to figure out what other people are thinking and feeling. And the hardest thing of all is to figure out that what people think and feel isn’t actually exactly like what we think feel. Anyone who’s followed politics can testify to how hard that is for some people to get. wanted to know if babies and young children could understand this really profound 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 tell you what he thinks, what you’ll get is a 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 the secret was broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give the babies two bowls food: one bowl of raw broccoli 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) then what Betty did was to take a little taste of food from bowl. And she would act as if she liked it she didn’t. So half the time, she acted as if she liked crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what she would do is a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she take a little bit 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 wanted. We did this with 15 and 18 month-old babies. And she would simply put her hand out and say, “Can you give some?”
So the question is: What would the baby give her, what liked or what she liked? And the remarkable thing that 18 month-old babies, just barely walking and talking, give her the crackers if she liked the crackers, but they give her 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 if she liked broccoli, like they couldn’t figure this out. But then after they for a long time, they would just give her the crackers, they thought everybody must like. So there are two really remarkable about this. The first one is that these little 18 month-old babies already discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they felt that they should do things to help other people get what they wanted.
Even more though, the fact that 15 month-olds didn’t do this suggests these 18 month-olds had learned this deep, profound fact human nature in the three months from when they were 15 months old. 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 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 you look at babies superficially, seem pretty useless. And actually in many ways, they’re worse useless, because we have to put so much time and energy into just keeping them alive. if we turn to evolution for an answer to puzzle of 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 us primates, but also including other mammals, birds, even like kangaroos and wombats, it turns out that 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 of the posterbirds for this idea are the birds up there. On one is a New Caledonian crow. And crows and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re smart as chimpanzees in some respects. And this is bird on the cover of science who’s learned how to a tool to get food. On the other hand, we have friend the domestic chicken. And chickens and ducks and geese and turkeys are basically as as dumps. So they’re very, very good at pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, the New Caledonian crow babies, fledglings. They depend on their moms to drop worms in their open mouths for as long as two years, which is really long time in the life 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 long childhood that seems to be connected to knowledge learning. Well what kind of explanation could we have this? Well some animals, like the chicken, seem to beautifully suited to doing just one thing very well. So they seem to beautifully suited to pecking grain in one environment. Other creatures, like crows, aren’t very good at doing anything in particular, but they’re extremely at learning about laws of different environments.
And of course, we human are way out on the end of the distribution like the crows. We have brains relative to our bodies by far than any other animal. We’re smarter, we’re more flexible, we learn more, we survive in more different environments, we migrated to the world and even go to outer space. And our babies and are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at least until they’re 23, we’re still those worms into those little open mouths.
All right, why would we this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in the world, but it has one disadvantage. And that one big disadvantage is that, until you 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 maybe a spear might work. would actually be better?” You want to know all that before the mastodons show up. And the way the evolutions seems to have solved that problem is with a kind of of labor. So the idea is that we have this early period 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 that we learned when we were babies and children and actually put them to work to do out there in the world.
So one way of thinking about is that babies and young children are like the research and development division of the species. So they’re the protected blue sky guys who just have go out and learn and have good ideas, and we’re production and marketing. have to take all those ideas that we learned when were children and actually put them to use. Another way of thinking about it instead of thinking of babies and children as being like defective grownups, 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, we’re the caterpillars who are inching along our narrow, grownup, adult path.
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If this is true, these babies are designed to learn — and this evolutionary story would children are for learning, that’s what they’re for — we might expect that they would have really powerful mechanisms. And in fact, the baby’s brain seems to be most powerful learning computer on the planet. But real are actually getting to be a lot better. And there’s been a in our understanding of machine learning recently. And it depends on the ideas of this guy, the Reverend Thomas Bayes, who was a statistician mathematician in the 18th century. And essentially what Bayes did was to provide mathematical way using probability theory to characterize, describe, the way that scientists find about the world. So what scientists do is they a hypothesis that they think might be likely to with. They go out and test it against the evidence. The evidence makes them change that hypothesis. they test that new hypothesis and so on and so forth. And what showed was a mathematical way that you could do that. that mathematics is at the core of the best learning programs that we have now. And some 10 years ago, I that babies might be doing the same thing.
So if you to know what’s going on 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 conditional probabilities that they’re revising to figure out how world works. All right, now that might seem like an even taller to actually demonstrate. Because after all, if you ask even grownups about statistics, look extremely stupid. How could it be that children doing statistics?
So to test this we used a that we have called the Blicket Detector. This is box that lights up and plays music when you some things on it and not others. And using this very simple machine, my lab and others done dozens of studies showing just how good babies are at learning the world. Let me mention just one that we did with Tumar Kushner, my student. If showed you this detector, you would be likely to to begin with that the way to make the detector would be to put a block on top of the detector. actually, this detector works in a bit of a strange way. if you wave a block over the top of the detector, you wouldn’t ever think of to begin with, the will actually activate two out of three times. Whereas, you do the likely thing, put the block on the detector, it will activate two out of six times. So the unlikely hypothesis actually has stronger evidence. It as 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 it go. And sure enough, the four year-olds used the evidence to the object on top 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 learning how to count. But unconsciously, they’re doing these quite complicated calculations 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 hypothesis about the world, that seems very unlikely to begin with. And studies we’ve just been doing in my lab, similar studies, we’ve show that four year-olds are actually better finding out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, children are using statistics to find out about the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. children do experiments we call it “getting into everything” or else “playing.”
And there’s been a bunch interesting studies recently that have shown this playing around is really a of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did was our Blicket Detectors. And what she did was show children that yellow ones it go and red ones didn’t, and then she showed them anomaly. And what you’ll see is that this little boy will go through five hypotheses in the of two minutes.
(Video) Boy: How about this? Same as the other side.
Alison Gopnik: Okay, so first hypothesis has just been falsified.
(Laughter)
Boy: This one up, and this one nothing.
AG: Okay, he’s got his notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every will recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, and needs 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, to try putting it out the other location. Not working either.
Boy: Oh, because the light goes only to here, not here. Oh, bottom of this 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 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 a — that is a particularly adorable and articulate little boy, but what Cristine discovered is is actually quite typical. If you look at the way play, when you ask them to explain something, what really do is do a series of experiments. This actually pretty typical of four year-olds.
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Well, what’s it like to this kind of creature? What’s it like to be one of 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 were conscious at all. And 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 happens for adults is 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 else sort of goes dark. we even know something about the way the brain does this.
So what happens when we attention is that the prefrontal cortex, the sort of executive part of our brains, sends a that makes a little part of our brain much flexible, more plastic, better at learning, and shuts down activity in the rest of our brains. So we have a very focused, purpose-driven of attention. If we look at babies and young 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 young are very bad at narrowing down to just one thing. But they’re very good at in lots of information from lots of different sources at once. And if you actually look their brains, you see that they’re flooded with these neurotransmitters that are really good inducing learning and plasticity, and the inhibitory parts haven’t come on yet. So when we say that and young 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 looking at the thing that’s important. That’s the kind of attention, the kind consciousness, that we might expect from those butterflies who are designed learn.
Well if we want to think about a way of a taste of that kind of baby consciousness as adults, I think the thing is think about cases where we’re put in new situation that we’ve never been in before — we fall in love with someone new, or when we’re a new city for the first time. And what then is not that our consciousness contracts, it expands, that those three days in Paris seem to be full of consciousness and experience than all the months of being a walking, talking, 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 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 crying 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 wonderful babies are. It’s to be a grownup. We can do things like our shoelaces and cross the street by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But if what we want is to like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be getting adults to start thinking more like children.
(Applause)