What is going on this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, would have said 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 that this baby’s thinking is like the thinking of most brilliant scientists.
Let me give you just one example of this. One thing that this could be thinking about, that could be going on in his mind, is to figure out what’s going on in the mind of other baby. After all, one of the things that’s hardest all of us to do is to figure out what other people are and feeling. And maybe the hardest thing of all to figure out that what other people think and feel isn’t exactly like what we think and feel. Anyone who’s followed politics can testify to how hard that is 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 ask them? Babies, all, can’t talk, and if you ask a three year-old to you what he thinks, what you’ll get is a beautiful stream of monologue about ponies and birthdays and things like that. how do we actually ask them the question?
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Well turns out that the secret was broccoli. What we did — Betty Rapacholi, who one of my students, and I — was actually to give the babies two bowls of food: one of raw broccoli and one bowl of delicious goldfish crackers. Now 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 she didn’t. So half the time, she acted as if she liked crackers 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 the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a 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 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 baby her, what they liked or what she liked? And the remarkable thing was that 18 month-old babies, barely walking and talking, would give her the crackers if she liked the crackers, but they 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 the broccoli, like they couldn’t figure this out. But then after they stared for a time, they would just give her the crackers, what they thought everybody must like. So there two really remarkable things about this. The first one is that these little 18 month-old babies have 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 things to help other people get what they wanted.
Even more remarkably though, the that 15 month-olds didn’t do this suggests that these 18 month-olds had learned deep, profound fact about human nature in the three months from when they were 15 old. So children both know more and learn more than we would have thought. And this is just one of hundreds and hundreds of over the last 20 years that’s actually demonstrated it.
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The question you might ask though is: do children learn so much? And how is it possible for them to learn much in such a 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, because we have to put much time and energy into just keeping them alive. But if we to evolution for an answer to this puzzle of we spend so much time taking care of useless babies, it turns out there’s actually an answer. If we look across many, many different species of animals, not us primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, it out that there’s a relationship between how long a childhood species has and how big their brains are compared to their bodies and how smart and flexible are.
And sort of the posterbirds for this idea are the birds up there. On one side is New Caledonian crow. And crows and other corvidae, ravens, rooks so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird the cover of science who’s learned how to use tool to get food. On the other hand, we 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 good at doing anything else. Well it out 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 two years, which is really long time in the life of a bird. Whereas the are actually mature within a couple of months. So childhood is the why the crows end up on the cover of Science and chickens end up in the soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what kind of could we have for this? Well some animals, like the chicken, seem to beautifully suited to doing just one thing very well. So seem to be beautifully suited to pecking grain in environment. Other creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about laws different environments.
And of course, we human beings are way out on the end 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 more different environments, we migrated to cover the world and even go to space. And our babies and children are dependent on us for longer than the babies of any other species. My is 23. (Laughter) And at least until they’re 23, we’re popping those worms into those little open mouths.
All right, would we see this correlation? Well an idea is that that strategy, learning strategy, is 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 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 to know all that before the mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind of division of labor. So the idea is we have this early period when we’re completely protected. We don’t have to anything. All we have to do is learn. And then as adults, can take all those things that we learned when we were babies and children and actually them to work to do things out there in the world.
So one way thinking about it is that babies and young children are like research and development division of the human 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 we were children and actually put them to use. Another way of thinking about is instead of thinking of babies and children as being like defective grownups, we think about them as being a different developmental stage the same species — kind of like caterpillars and butterflies — that they’re actually the brilliant butterflies who are flitting the garden and exploring, and we’re the caterpillars who are along our narrow, grownup, adult path.
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If 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 would have really powerful learning mechanisms. And in fact, the baby’s brain seems to be most powerful learning computer on the planet. But real computers are actually getting to be lot better. And there’s been a revolution in our of machine learning recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician and mathematician the 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 world. So what scientists do is they have a hypothesis that they might be likely to start with. They go out and test against the evidence. The evidence makes them change that hypothesis. they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way you could do that. And that mathematics is at core of the best machine learning programs that we have now. And 10 years ago, I suggested that babies might be the same 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 calculations with conditional probabilities that they’re revising to figure out how the works. All right, now that might seem like an even order to actually demonstrate. Because after all, if you ask grownups about statistics, they look extremely stupid. How could be that children are doing statistics?
So to test we used a machine that we have called the Detector. This is a box that lights up and plays music when you put some things on it not others. And using this very simple machine, my and others have done dozens of studies showing just how good babies are at learning about world. Let me mention just one that we did with Tumar Kushner, my student. If I showed you detector, you would be likely to think to begin with that the way to make detector go would be to put a block on top the detector. But actually, this detector works in a bit of a strange way. Because you wave a block over the top of the detector, something you wouldn’t ever think to begin with, the detector will actually activate two out of 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 actually has stronger evidence. It looks as if the is a more effective strategy than the other strategy. So did just this; we gave four year-olds this pattern of evidence, and we just them to make it go. And sure enough, the year-olds used the evidence to wave the object on top of the detector.
Now there are things 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 quite complicated calculations that will give them a conditional probability measure. the other interesting thing is that they’re using that evidence get to an idea, get to a hypothesis about the world, that seems very unlikely begin with. And in studies we’ve just been doing in lab, similar studies, we’ve show that four year-olds are actually better at finding out an hypothesis than adults are when we give them exactly the task. So in these circumstances, the children are using statistics find out about the world, but after all, scientists 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 shown this 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 she did was show children that ones made it go and red ones didn’t, and then she them 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 has been falsified.
(Laughter)
Boy: This one lighted up, and one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s 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. He told the to do this, to try putting it out onto other location. Not working either.
Boy: Oh, because the light goes to here, not here. Oh, the bottom of this box has electricity in here, 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 make it light up and two on this one to make light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and articulate little boy, but Cristine discovered is this is actually quite typical. If you at the way children play, when you ask them to something, what they 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 be this kind creature? What’s it like to be one of these brilliant butterflies who can five hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have said that babies and young children were conscious if they were conscious at all. And I think just the opposite is true. think babies and children are actually more conscious than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and consciousness look kind of 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 thing we’re attending to becomes extremely bright and vivid, and everything else of goes dark. And we even know something about the way brain does this.
So what happens when we pay attention is that the cortex, the sort of executive part of our brains, a signal that makes a little part of our much more flexible, more plastic, better at learning, and down activity in all the rest of our brains. So have a very focused, purpose-driven kind of attention. If we look babies and young children, we see something very different. think babies and young children seem to have more of lantern of consciousness than a spotlight of consciousness. So and young children are very bad at narrowing down to just thing. But they’re very good at taking in lots information from lots of different sources at once. And you actually look in their brains, you see that they’re flooded with these neurotransmitters that are really at inducing learning and plasticity, and the inhibitory parts haven’t come on yet. when we say that babies 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 the things that could tell them something and just looking at 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 about a way of getting a taste of that kind of baby as adults, I think the best thing is think about where we’re put in a new situation that we’ve never in before — when we fall in love with new, or when we’re in a new city for the first time. what happens then is not that our consciousness contracts, it expands, so that those three days Paris seem to be more full of consciousness and experience than all months of being a walking, talking, faculty meeting-attending zombie back home. And by the way, that coffee, that coffee you’ve been drinking downstairs, actually mimics the effect those baby neurotransmitters. So what’s it like to be a baby? It’s being in love in Paris for the first time you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but does tend to leave you waking up crying at three o’clock in morning.
(Laughter)
Now it’s good to be a grownup. I don’t want say too much about how wonderful babies are. It’s good to be grownup. We can do things like tie our shoelaces and the street by ourselves. And it makes sense that we put a lot effort into making babies think like 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 of time we should be getting the adults to start more like children.
(Applause)