What is going on in this baby’s mind? If you’d 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 another person or understand cause and effect. In the last 20 years, developmental science completely overturned that picture. So in some ways, we think that this baby’s thinking is the thinking of the most brilliant scientists.
Let me give you just one example this. One 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 things that’s hardest for of us to do is to figure out what other people are thinking and feeling. And maybe hardest thing of all is to figure out that what other people and feel isn’t actually exactly like what we think and feel. Anyone who’s followed can testify to how hard that is for some people to get. We wanted to know babies and young children could understand this really profound about other people. Now the question is: How could we ask them? Babies, 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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it turns out that the secret was broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give the babies two bowls of food: bowl of raw broccoli and one bowl of delicious goldfish crackers. Now all of babies, even in Berkley, like the crackers and don’t the raw broccoli. (Laughter) But then what Betty did was to take a taste of food from each bowl. And she would as if she liked it or she didn’t. So half the time, she acted as she liked the crackers and didn’t like the broccoli — like a baby and any other sane person. But the time, what she would do is take a little bit of the 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. I tasted the crackers. Eww, yuck.” So she’d as if what she wanted was just the opposite of what the babies wanted. We did this 15 and 18 month-old babies. And then she would simply her hand out and say, “Can you give me some?”
So the question is: What the baby give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just barely walking talking, would give her the crackers if she liked the crackers, but they give her the broccoli if she liked the broccoli. On other hand, 15 month-olds would stare at her for a time if she acted as if she liked the broccoli, like they couldn’t figure this out. But then after stared for a long time, they would just give her crackers, what they thought everybody must like. So there are two really things about this. The first one is that these 18 month-old babies have already discovered this really profound fact about human nature, that we don’t always want same thing. And what’s more, they felt that they should do things to help other 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 about human nature in the three months from when they were 15 old. So children both know more and learn more we ever would have thought. And this is just one of and hundreds of studies over the last 20 years that’s actually demonstrated it.
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The question you ask though is: Why do children learn so much? And how it possible for them to learn so much in a short time? I mean, after all, if you look at babies superficially, seem pretty useless. And actually in many ways, they’re than useless, because we have to put so much and energy into just keeping them alive. But if we to evolution for an answer to this puzzle of why we spend so time taking care of useless babies, it turns out that there’s actually an answer. If we across many, many different species of animals, not just us primates, but also including other mammals, birds, marsupials like kangaroos and wombats, it turns out that there’s a relationship between long a childhood a species has and how big brains are compared to their bodies and how smart and flexible they are.
And of the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as smart as chimpanzees in respects. And this is a bird on the cover of science who’s learned to use a tool to get food. On the other hand, we have our friend the 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 good at doing anything else. Well it turns out the babies, the New Caledonian crow babies, are fledglings. depend on their moms to drop worms in their open mouths for as long as two years, which 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 why the crows up on the cover of Science and the chickens up in the soup pot.
There’s something about that long childhood that seems to connected to knowledge and learning. Well what kind of explanation could we have for this? Well some animals, the chicken, seem to be 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 anything in particular, they’re extremely good at learning about laws of different environments.
And of course, we human beings way out on the end of the distribution like the crows. We have bigger brains relative to our by far than any other animal. We’re smarter, we’re more flexible, we can learn more, we survive in different environments, we migrated to cover the world and even to outer 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, why we see this correlation? Well an idea is that strategy, that learning strategy, is an extremely powerful, great strategy getting on in the world, but it has one big disadvantage. And that big disadvantage is that, until you actually do all that learning, you’re going to helpless. So you don’t want to have the mastodon charging at and be saying to yourself, “A slingshot or maybe spear might work. Which would actually be better?” You to know all that before the mastodons actually show up. And the the evolutions seems to have solved that problem is with kind of division of labor. So the idea is that we this early period when we’re completely protected. We don’t have to do anything. All have to do is learn. And then as adults, we can take those things that we learned when we were babies and children and actually put them to work to things out there in the world.
So one way of about it 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 to go out and learn and have good ideas, and we’re production marketing. We have to take all those ideas that learned when we were children and actually put them use. Another way of thinking about it is instead of thinking of babies and children as like defective grownups, we should think about them as being different developmental stage of the same species — kind of caterpillars and butterflies — except that they’re actually the butterflies who are flitting around the garden and exploring, and we’re the who are inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to learn — and evolutionary story would say children are for learning, that’s they’re for — we might expect that they would really powerful learning mechanisms. And in fact, the baby’s seems to be the most powerful learning computer on the planet. real computers are actually getting to be a lot better. there’s been a revolution in our understanding of machine learning recently. And it all depends on the of this guy, the Reverend Thomas Bayes, who was a statistician and in the 18th century. And essentially what Bayes did was to a mathematical way using probability theory to characterize, describe, way that scientists find out about the world. So what scientists is they have a hypothesis that they think might be likely to start with. They go out test it 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 the core the best machine 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 eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies are making complicated calculations with conditional probabilities that they’re revising to figure how the world works. All right, now 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 that are doing statistics?
So to test this we used a that we have called the Blicket Detector. This is a box that lights up and plays music when put some things on it and not others. And this very simple machine, my lab and others have dozens of studies showing just how good babies are at about the world. Let me mention just one that did with Tumar Kushner, my student. If I showed you this detector, you would be to think to begin with that the way to make detector go would be to put a block on of the detector. But actually, this detector works in a of a strange way. Because if you wave a block the top of the detector, something you wouldn’t ever think to begin with, the 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 of six times. So unlikely hypothesis actually has stronger evidence. It looks as if the waving is a more strategy than the other strategy. So we did just this; gave four year-olds this pattern of evidence, and we asked them to make it go. And sure enough, the four year-olds used evidence to wave the 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 quite complicated calculations that will give them conditional probability measure. And the other interesting thing is that they’re using that evidence get to an idea, get to a hypothesis about world, that seems very unlikely to begin with. And in studies we’ve been doing in my lab, similar studies, we’ve show that four year-olds are actually better at out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, the children are using to find out about the world, but after all, scientists also do experiments, and wanted to see if children are doing experiments. When children experiments we call it “getting into everything” or else “playing.”
And there’s been a bunch of interesting studies recently have shown this playing around is really a kind of research program. Here’s one from Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. what she did was show children that yellow ones made it go 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 two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and this nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making light up. (Laughter) I don’t know.
AG: Every scientist recognize 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 next idea. He told the experimenter to do this, try putting it out onto the other location. Not either.
Boy: Oh, because the light goes only to here, not here. Oh, the bottom this box has electricity in here, but this doesn’t electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s up. So when you put four. So you put four this one to make it light up and two on this to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and articulate little boy, but what discovered is this is actually quite typical. If you at the way children play, when you ask them explain something, what they 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 of these brilliant butterflies who can test five hypotheses two minutes? Well, if you go back to those 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 are actually more than we are as adults. Now here’s what we know how adult consciousness works. And adults’ attention and consciousness look kind of like a spotlight. what happens for adults is we decide that something’s relevant important, we should pay attention to it. Our consciousness of that thing that we’re attending to extremely bright and vivid, and everything else sort of dark. And we even know something about the way the does this.
So what happens when we pay attention is the prefrontal cortex, the sort of executive part of brains, sends a signal that makes a little part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest of our brains. So have a very focused, purpose-driven kind of attention. If we look at babies and young children, we something very different. I think babies and young children to have more of a lantern of consciousness than a of consciousness. So babies and young children are very bad at narrowing down to one thing. But they’re very good at taking in lots of from lots of different sources at once. And if you actually look in their brains, 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 at not attention. So they’re bad at getting rid of all the interesting things that could tell them something just looking at the thing that’s important. That’s the of attention, the kind of consciousness, that we might expect from butterflies who are designed to learn.
Well if we want to think about a way of getting taste of that kind of baby consciousness as adults, think the best thing is think about cases where we’re put in new situation that we’ve never been in before — when fall in love with someone new, or when we’re in a new city the first time. And what happens then is not our consciousness contracts, it expands, so that those three days in Paris seem to be more of consciousness and experience than all the months of 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 those baby neurotransmitters. what’s it like to be a baby? It’s like being in love in Paris for the first after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it does tend leave you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say too much how wonderful babies are. It’s good to be a grownup. We can things like tie our shoelaces and cross the street ourselves. And it makes sense that we put a 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 be getting the to start thinking more like children.
(Applause)