What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would have that this baby was irrational, illogical, egocentric — that he couldn’t take the perspective of another person or cause and effect. In the last 20 years, developmental science has completely that picture. So in some ways, we think that this baby’s thinking is like the of the most brilliant scientists.
Let me give you just example of this. One thing that this baby could thinking about, that could be going on in his mind, is trying to out what’s going on in the mind of that other baby. After all, one of the that’s hardest for all of us to do 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 exactly like what we think and feel. Anyone who’s politics can testify to how hard that is for some people to get. We 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 to tell what he thinks, what you’ll get is a beautiful stream of consciousness about ponies and birthdays and things like that. So do we actually ask them the question?
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it turns out that 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 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 did to take a little taste of food from each bowl. And she would act as if she liked or she didn’t. So half the time, she acted as she liked the crackers and didn’t like the broccoli — just like a baby any other sane person. But half the time, what she would do is take little 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 the crackers. Eww, yuck.” So she’d act as if she wanted was just the opposite of what the babies wanted. did this with 15 and 18 month-old babies. And then she would simply put her hand and say, “Can you give me some?”
So the is: What would the baby give her, what they liked what she liked? And the remarkable thing was that 18 month-old babies, just walking and talking, would 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 would stare at for a long time if she acted as if she the broccoli, like they couldn’t figure this out. But then after they stared 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 have already discovered this really profound about human nature, that we don’t always want the same thing. And what’s more, they felt 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 about human nature in the three months from when they 15 months old. So children both know more and learn more we ever would have thought. And this is just of hundreds and hundreds of studies over the last 20 years that’s actually demonstrated it.
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The you might ask though is: Why do children learn so much? how is it possible for them to learn so much in such a 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 to put so much time and energy into just them alive. But if we turn to evolution for answer to this puzzle of why we spend so much time taking care useless babies, it turns out that there’s actually an answer. If we look across many, different species of animals, not just us primates, but also other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s a relationship how long a childhood a species has and how big their are compared to their bodies and how smart and flexible they are.
And sort the posterbirds for this idea are the birds 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 smart as chimpanzees in some respects. And this is bird on the cover of science who’s learned how to use tool to get food. On the other hand, we have our the domestic chicken. And chickens and ducks and geese and turkeys basically as dumb as dumps. So they’re very, very good pecking for grain, and they’re not much good at doing else. Well it turns out that the babies, the 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 actually mature within a couple of months. So childhood is the reason why crows end up on the cover of Science and the chickens end up in the soup pot.
There’s about that long childhood that seems to be connected to knowledge and learning. Well what kind of explanation we have for this? Well some animals, like the chicken, seem to be beautifully suited to just one thing very well. So they seem to be suited to pecking grain in one environment. Other creatures, like the crows, aren’t very good doing anything in particular, but they’re extremely good at learning about laws of environments.
And of course, we human beings are way out on the end of the 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 to outer space. And our babies and children are on us for much longer than the babies of other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into those little mouths.
All right, why would we see this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in world, but it has one 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 to yourself, “A slingshot or maybe a spear might work. Which actually be better?” You want to know all that the mastodons actually show up. And the way the evolutions to have solved that problem is with a kind of division labor. So the idea is that we have 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 we learned when we were babies and children and actually put to work to do things out there in the world.
So one way of thinking about is that babies and young children are like the and development division of the human species. So they’re protected blue sky guys who just have to go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas we learned when we were children and actually put them to use. way of thinking about it is instead of thinking of and children as being like defective grownups, we should think about them as a different developmental stage of the same species — of like caterpillars and butterflies — except that they’re the brilliant butterflies who are flitting around the garden exploring, and we’re the 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 for learning, that’s what they’re for — might expect that they would have really powerful learning mechanisms. in fact, the baby’s brain seems to be the most powerful learning computer on planet. But real computers are actually getting to be lot better. And there’s been a revolution in our understanding machine learning recently. And it all depends on the ideas of this guy, the Reverend Thomas Bayes, who a statistician and mathematician in the 18th century. And essentially what Bayes did to provide a mathematical way using probability theory to characterize, describe, the way that scientists find out about world. So what scientists do is they have a hypothesis that they think be likely to start with. They go out and test it against the evidence. evidence makes them change that hypothesis. Then they test that new and so on and so forth. And what Bayes showed a mathematical way that you could do that. And that mathematics is at the 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 on underneath those beautiful brown eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies are actually making complicated with conditional probabilities that they’re revising to figure out how world works. All right, now that might seem like an even taller order to actually demonstrate. Because all, if you ask even grownups about statistics, they extremely stupid. How could it be that children are statistics?
So to test this we used a machine that have called the Blicket Detector. This is a box that up and plays music when you put some things on it and others. And using this very simple machine, my lab and others done dozens of studies showing just how good babies 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 with that the way to make the detector go be to put a block on top of the detector. But actually, this detector works in a bit of strange way. Because if you wave a block over the of the detector, something you wouldn’t ever think of to begin with, detector will actually activate two out of three times. Whereas, if you do likely thing, put the block on the detector, it will only activate two out six times. So the unlikely hypothesis actually has stronger evidence. looks as if the waving is a more effective strategy than the other strategy. So we did this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And enough, the four year-olds used the evidence to wave the object on top of detector.
Now there are two things that are really about this. The first one is, again, remember, these are four year-olds. They’re just learning how count. But unconsciously, they’re doing these quite complicated calculations that will give them a conditional probability measure. And other 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. And studies we’ve just been doing in my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than adults are when give them exactly the same task. So in these circumstances, the children are using statistics to out about the world, but after all, scientists also experiments, and we wanted to see if children are doing experiments. When children do experiments 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 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 it go and red ones didn’t, and then she showed them an anomaly. And what you’ll see that this little boy will go through five hypotheses in the space of minutes.
(Video) Boy: How about this? Same as the other side.
Alison Gopnik: Okay, so his hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this light up. (Laughter) don’t know.
AG: Every scientist will recognize that expression despair.
(Laughter)
Boy: Oh, it’s because this needs to like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his idea. He told the experimenter to do this, to putting it out onto the other location. Not working either.
Boy: Oh, because 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 to make it light up and two on this to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — is a particularly adorable and articulate little boy, but what Cristine discovered is this actually 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 typical of four year-olds.
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Well, what’s like to be this kind of creature? What’s it like to be one of brilliant butterflies who can test five hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have said that babies young children were barely conscious if they were conscious 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 what we know about how consciousness works. And adults’ attention and consciousness look kind of 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 bright and vivid, everything else sort of goes dark. And we even know something about the way the brain this.
So what happens when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a signal that makes a little part of our brain more flexible, more plastic, better at learning, and shuts activity in all the rest of our brains. So we a very focused, purpose-driven kind of attention. If we look at and young children, we see something very different. I think babies and young seem to have more of a lantern of consciousness a 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 lots of information lots of different sources at once. And if you actually look in brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and inhibitory parts haven’t come on yet. So when we that babies and young children are bad at paying attention, what really mean is that they’re bad at not paying attention. So they’re at getting rid of all the interesting things that could tell them something and just looking at thing that’s important. That’s the kind of attention, the kind consciousness, that we might expect from those butterflies who are designed to learn.
Well we want to think about a way of getting a taste of that kind of baby consciousness adults, I think the best thing is think about cases where we’re in a new situation that we’ve never been in — when we fall in love with someone new, or when we’re in a new city the first time. And what happens then is not that our contracts, it expands, so that those three days in Paris to be more full of consciousness and experience than all the months of a walking, talking, faculty meeting-attending zombie back home. And the way, that coffee, that wonderful coffee you’ve been downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it like to be baby? It’s like being in love in Paris for first time after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it tend to leave you waking up crying at three o’clock the morning.
(Laughter)
Now it’s good to be a grownup. don’t want to say too much about how wonderful are. It’s good to be a grownup. We can things like tie our shoelaces and cross the street by ourselves. And it sense that we put a lot of effort into babies think like adults do. But if what we want is to like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some the time we should be getting the adults to thinking more like children.
(Applause)