What going on in this baby’s mind? If you’d asked this 30 years ago, most people, including psychologists, would have that this baby was irrational, illogical, egocentric — that he couldn’t take the of another person or understand cause and effect. In the 20 years, developmental science has completely overturned that picture. So in some ways, 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 baby could thinking about, that could be going on in his mind, trying to figure out what’s going on in the of that other baby. After all, one of the things that’s hardest for all of us do is to figure out what other people are thinking and feeling. And maybe the thing of all is to figure out that what people think and feel isn’t actually exactly like what we think and feel. 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 thing about other people. Now the question is: How we ask them? Babies, after all, can’t talk, and if you ask three year-old to tell you what he thinks, what you’ll get is a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how do we actually ask them question?
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Well it turns out that the secret was broccoli. What did — Betty Rapacholi, who was one of my students, and — was actually to give the babies two bowls of food: one bowl of broccoli and one bowl of delicious goldfish crackers. Now all of the babies, even in Berkley, like crackers and don’t like the raw broccoli. (Laughter) But then what did was to take a little taste of food from each bowl. she would act as if she liked it or she didn’t. So the 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 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. I tasted the crackers. Eww, yuck.” So she’d as if what she wanted was just the opposite of 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 me some?”
So the question is: would the baby give her, what they liked or she liked? And the remarkable thing was that 18 month-old babies, barely walking and talking, would give her the crackers she liked the crackers, but they would give her the broccoli if she the broccoli. On the other hand, 15 month-olds would stare her for a long time if she acted as if she liked the broccoli, like couldn’t figure this out. But then after they stared for a time, they would just give her the crackers, what thought everybody must like. So there are two really remarkable things about this. The first is that these little 18 month-old babies have already discovered this really profound fact about nature, that we don’t always want the same thing. And what’s more, felt that they should actually do things to help other people get what they wanted.
Even more though, the fact that 15 month-olds didn’t do this that these 18 month-olds had learned this deep, profound fact about human nature in the months from when they were 15 months old. So children both know and learn more than we ever would have thought. And this just one of hundreds and hundreds of studies over the last 20 years that’s demonstrated it.
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The question you might ask though is: Why do children 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 put so much time and energy into just keeping alive. But if we turn to evolution for an answer to this puzzle why we spend so much time taking care of useless babies, it turns out that there’s an answer. If we look across many, many different of 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 how smart and flexible they are.
And sort of 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 birds. They’re as smart as chimpanzees in some respects. And this is a on the cover of science who’s learned how to a tool to get food. On the other hand, we our friend the domestic chicken. And chickens and ducks and geese and are basically as dumb as dumps. So they’re very, very good at for grain, and they’re not much good at doing anything else. Well it turns out that babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little open mouths for as as two years, which is a really long time in the of a bird. Whereas the chickens are actually mature a couple of months. So childhood is the reason why the crows end up on the cover of and the chickens end up in the soup pot.
There’s something about that long that seems to be connected to knowledge and learning. what kind of explanation could we have for this? Well some animals, like the chicken, seem to beautifully suited to doing just one thing very well. they seem to be beautifully suited to pecking grain in one environment. Other creatures, the crows, aren’t very good at doing anything in particular, but they’re extremely good at learning about laws different environments.
And of course, we human beings are way out on the of the distribution like the crows. We have bigger relative to our bodies by far than any other animal. We’re smarter, we’re flexible, we can learn more, we survive in more different environments, we to cover the world and even go to outer space. And our babies and children dependent on us for much longer than the babies of any other species. My son 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 strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it has big disadvantage. And that one big disadvantage is that, until you do all that learning, you’re going to be helpless. So don’t want to have the mastodon charging at you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” want to know all that before the mastodons actually show up. And the way the evolutions seems have solved that problem is with a kind of division of labor. the idea is that we have this early period we’re completely protected. We don’t have to do anything. All we have to is learn. And then as adults, we can take all those things that learned when we were babies and children and actually them to work to do things out there in world.
So one way of thinking about it is that and young children are like the research and development division of the species. So they’re the protected blue sky guys who have to go out and learn and have good ideas, and we’re production and marketing. We have to take those ideas that we learned when we were children and actually put them to use. Another way of about it is instead of thinking of babies and children being like defective grownups, we should think about them as being a different stage of the same species — kind of like caterpillars and — except that they’re actually the brilliant butterflies who are flitting around 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 — and this evolutionary story say children are for learning, that’s what they’re for — we might expect that they have really powerful learning mechanisms. And in fact, the baby’s brain seems be the most powerful learning computer on the planet. But real computers are actually to be a lot better. And there’s been a revolution in our understanding of learning recently. And it all depends on the ideas this guy, the Reverend Thomas Bayes, who was a statistician and mathematician the 18th century. And essentially what Bayes did was to provide a way using probability theory to characterize, describe, the way that scientists find out the world. So what scientists do is they have a hypothesis that they think be likely to start with. They go out and test against the evidence. The evidence makes them change that hypothesis. Then they test that new hypothesis and so on so forth. And what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of the machine learning programs that we have now. And some 10 years ago, I suggested babies might be doing the same thing.
So if want to know what’s going on underneath those beautiful brown eyes, think it actually looks something like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional probabilities that they’re revising to figure how the world works. All right, now that might seem an even taller order to actually demonstrate. Because after all, if ask even 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 Blicket Detector. This is a box lights up and plays music when you put some things on it not others. And using this very simple machine, my lab and others have done dozens 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 you this detector, you would be likely to think to begin with that the way make the detector go would be to put a block on top of the detector. But actually, this works in a bit of a strange way. Because if you wave a block over the of the detector, something you wouldn’t ever think of to begin with, the detector will actually two out of three times. Whereas, if you do the likely thing, put block on the detector, it will only activate two out six times. So the unlikely hypothesis actually has stronger evidence. It looks as if the waving is more effective strategy than the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just asked them to make it go. And enough, the four year-olds used the evidence to wave object on top of the detector.
Now there are two things that are really interesting this. The first one is, again, remember, these are 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 other interesting thing is that they’re using that evidence get to an idea, get to a hypothesis about the world, that seems very to begin with. And in studies we’ve just been in my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than are when we give them exactly the same task. So in these circumstances, the children using statistics to find out about the world, but after all, scientists also experiments, and we wanted to see if children are doing experiments. When do experiments we call it “getting into everything” or “playing.”
And there’s been a bunch of interesting studies recently that have shown this playing around really a kind of experimental research program. Here’s one from Cristine Legare’s lab. Cristine did was use our Blicket Detectors. And what she did was show children that yellow ones made go and red ones didn’t, and then she showed them an anomaly. what you’ll see is that this little boy will go five 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 one nothing.
AG: Okay, he’s his experimental notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: scientist 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 out onto the other location. Not working either.
Boy: Oh, because the light only to here, not here. Oh, the bottom of this box has electricity in here, but 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 it light up two on this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that is particularly adorable and articulate little boy, but what Cristine discovered this is actually quite typical. If you look at way children play, when you ask them to explain something, what really do is do a series of experiments. This is pretty typical of four year-olds.
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Well, what’s it like be this kind of creature? What’s it like to be one of these brilliant who can test five hypotheses in two minutes? Well, you go back to those psychologists and philosophers, a of them have said that babies and young children barely conscious if they were conscious at all. And I think just the is true. I think babies and children are actually more conscious than we are as adults. here’s what we know about how adult consciousness works. And adults’ and consciousness look kind of like a spotlight. So what happens for adults is we that something’s relevant or important, we should pay attention to it. Our of that thing that we’re attending to becomes extremely and vivid, and everything else sort of goes dark. we even know something about the way the brain does this.
So what happens when pay attention is that the prefrontal cortex, the sort of executive part of our brains, sends signal that makes a little part of our brain more flexible, more plastic, better at learning, and shuts down activity all the rest of our brains. So we have a very focused, purpose-driven kind of attention. If look at babies and young children, we see something different. I think babies and young children seem to have of a lantern of consciousness than a spotlight of consciousness. babies and 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 actually look their brains, you see that they’re flooded with these that are really good at inducing learning and plasticity, the inhibitory parts haven’t come on yet. So when we say that babies and young children are bad paying attention, what we really mean is that they’re at 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 of consciousness, that we expect from those butterflies who are designed to learn.
Well if want 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 put in a new that we’ve never been in before — when we fall in with someone new, or when we’re in a new city for the first time. And what then is not that our consciousness contracts, it expands, so that those three in Paris seem to be more full of consciousness experience than all the months of being a walking, talking, faculty meeting-attending zombie back home. And by the way, coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics the effect of baby neurotransmitters. So what’s it like to be a baby? It’s like being in love in Paris for first time after you’ve had three double-espressos. (Laughter) That’s a fantastic to be, but it does tend to leave you waking up at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say much about how wonderful babies are. It’s good to a grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that we put a of effort into making babies think like adults do. But if what we is to be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be getting the to start thinking more like children.
(Applause)