What going on in this baby’s mind? If you’d asked 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 person or cause and effect. In the last 20 years, developmental science has overturned that picture. So in some ways, we think this baby’s thinking is like the thinking of the 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 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 and feeling. And maybe the hardest thing of all is to figure that what other people think and feel isn’t actually exactly like what think and feel. Anyone who’s followed politics can testify how hard that is for some people to get. We wanted know if babies and young children could understand this really profound thing about people. Now the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old to tell you what thinks, what you’ll get is a beautiful stream of monologue about ponies and birthdays and things like that. So how we actually ask them the question?
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Well it turns out that the secret was broccoli. we did — Betty Rapacholi, who was one of my students, I — was actually to give the babies two bowls of food: bowl of raw broccoli and one bowl of delicious crackers. Now all of the babies, even in Berkley, like the crackers and don’t like raw broccoli. (Laughter) But then what Betty did was to take a little taste food from each bowl. And she would act as if she liked it or didn’t. So half the time, she acted as if she liked the crackers and didn’t like the — just like a baby and any other sane person. But half the time, what would do is take a little bit of the broccoli and go, “Mmmmm, broccoli. I the broccoli. Mmmmm.” And then she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d act as what she wanted was just the opposite of what the babies wanted. We did with 15 and 18 month-old babies. And then she would simply put her out 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, barely walking and talking, would give her the crackers she liked the crackers, but they would give her the broccoli if she liked the broccoli. On other hand, 15 month-olds would stare at her for a long time if she acted as if liked the broccoli, like they couldn’t figure this out. then after they stared for a long time, they just give her the crackers, what they thought everybody like. So there are two really remarkable things about this. The first one is that these little 18 month-old have already discovered this really profound fact about human nature, we don’t always want the same thing. And what’s more, they felt that should actually do things to help other people get what wanted.
Even more remarkably though, the fact that 15 month-olds didn’t this suggests that these 18 month-olds had learned this deep, fact about human nature in the three months from when they 15 months old. So children both know more and more than we ever would have thought. And this is one of hundreds and hundreds of studies over the last 20 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 in such a time? I mean, after all, if you look at babies superficially, they seem pretty useless. And in many ways, they’re worse than useless, because we have to so much time and energy into just keeping them alive. But we turn to evolution for an answer to this puzzle of why we spend much 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 primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a relationship between how long a childhood species has and how big their brains are compared to their bodies how smart and flexible they are.
And sort of the posterbirds this idea are the birds up there. On one side is a New Caledonian crow. And crows and corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird on the cover science who’s learned how to use a tool to get food. On other hand, we have our friend the domestic chicken. And and ducks and geese and turkeys are basically as as dumps. So they’re very, very good at pecking grain, and they’re not much good at doing anything else. it turns out that the babies, the New Caledonian babies, are fledglings. They depend on their moms to drop in their little open mouths for as long as two years, which is a really long time the life of a bird. Whereas the chickens are actually mature within a couple of months. So childhood the reason why the crows end up on the cover of Science and the chickens end up the soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what kind of explanation could have for this? Well some animals, like the chicken, seem 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 anything in particular, but they’re extremely good at learning about of different environments.
And of course, we human beings are way out 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 flexible, we can learn more, we survive in more different environments, we migrated to cover world and even go to outer space. And our babies and children are dependent on us for much than the babies of any other species. My son 23. (Laughter) And at least until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see this correlation? Well idea is that that strategy, that learning strategy, is an extremely powerful, great strategy for on in the world, but it has one big disadvantage. And one 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 way the seems to have solved that problem is with a kind 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 we have to do learn. And then as adults, we can take all those things that we learned when we babies and children and actually put them to work do things out there in the world.
So one way of thinking about it is that and young children are like the research and development division of the human species. So they’re the blue sky guys who just have to go out learn and have good ideas, and we’re production and marketing. We have to take all those that we learned when we were children and actually put them to use. Another way of thinking about 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 like caterpillars and butterflies — except that they’re actually brilliant butterflies who are flitting around the garden and exploring, we’re the caterpillars who are inching along our narrow, grownup, path.
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If this is true, if these babies are designed learn — and this evolutionary story would say children are learning, that’s what they’re for — we might expect that they would really powerful learning mechanisms. And in fact, the baby’s brain to be the most powerful learning computer on the planet. But real computers are actually getting be a lot better. And there’s been a revolution in our understanding of machine recently. And it all depends on the ideas of this guy, the Reverend Thomas Bayes, who was statistician and mathematician in the 18th century. And essentially what Bayes was to provide a mathematical way using probability theory characterize, describe, the way that scientists find out about the world. what scientists do is they have a hypothesis that think might be likely to start with. They go out and it against the evidence. The evidence makes them change that hypothesis. Then they that new hypothesis and so on and so forth. And what Bayes showed was mathematical way that you could do that. And that mathematics at the core of the best machine learning programs that have now. And some 10 years ago, I suggested that babies might be doing the thing.
So if you want to know what’s going on underneath those brown eyes, I think it actually looks something like this. This Reverend Bayes’s notebook. So I think those babies are actually making complicated calculations 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 it be that children are doing statistics?
So to this we used a machine that we have called the Blicket Detector. This is a box that up and plays music when you 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 learning about the world. Let me mention just one that did with Tumar Kushner, my student. If I showed this detector, you would be likely to think to begin that the way to make the detector go would be put a block on top of the detector. But actually, this detector works in a of a strange way. Because if you wave a block over the top the detector, something you wouldn’t ever think of to with, the detector will actually activate two out of three times. Whereas, if you do the likely thing, the block on the detector, it will only activate out of six times. So the unlikely hypothesis actually has stronger evidence. looks as if the waving is a more effective than the other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked to make it go. And sure enough, the four year-olds used evidence to wave the object on top of the detector.
Now there two things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning how to count. But unconsciously, they’re these quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re that evidence to get to an idea, get to a hypothesis about the world, seems very unlikely to begin with. And in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better at finding an unlikely hypothesis than adults are when we give them exactly the same task. So these circumstances, the children are using statistics to find out about the world, after all, scientists also do experiments, and we wanted to if children are doing experiments. When children do experiments we call it “getting into everything” or “playing.”
And there’s been a bunch of interesting studies that have shown this playing around is really a of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did 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 an anomaly. And 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 been falsified.
(Laughter)
Boy: This one lighted up, and one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this up. (Laughter) I don’t know.
AG: Every scientist will that expression of despair.
(Laughter)
Boy: Oh, it’s because needs to be like this, and this needs to like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now is his next idea. He told the experimenter to this, to try putting it out onto the other location. working either.
Boy: Oh, because the light goes only 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 when put four. So you put four on this one make it light up and two on this one to 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 is actually 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 of four year-olds.
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Well, what’s it like be this kind of creature? What’s it like to one of these brilliant butterflies who can test five hypotheses in two minutes? Well, if go back to those psychologists and philosophers, a lot of them said that babies and young children were barely conscious if they conscious at all. And I think just the opposite is true. think babies and children are actually more conscious than we as adults. Now here’s what we know about how adult consciousness works. And adults’ attention and consciousness kind of like a spotlight. So what happens for adults we decide that something’s relevant or important, we should pay to it. Our consciousness of that thing that we’re attending to becomes bright and vivid, and everything else sort of goes dark. And we know something about the way the brain does this.
So what happens when we pay attention that the prefrontal cortex, the sort of executive part of our brains, sends a signal makes a little part of our brain much more flexible, more plastic, at learning, and shuts down activity in all the rest of brains. So we have a very focused, purpose-driven kind of attention. If look at babies and young children, we see something very different. I think babies young children seem to have more of a lantern of consciousness than a of consciousness. So 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 look in their brains, you see that they’re flooded with neurotransmitters that are really good at inducing learning and plasticity, and the inhibitory parts haven’t come yet. So when we say that babies and young children bad at paying attention, what we really mean is that they’re bad at paying attention. So they’re bad at getting rid of all the interesting things could tell them something and just looking at the thing that’s important. That’s the kind of attention, kind of consciousness, that we might expect from those butterflies who designed to learn.
Well if we want to think about a way getting a taste of that kind of baby consciousness as adults, I think the best thing is think cases where we’re put 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 for the first time. And what happens then is not that consciousness contracts, it expands, so that those three days Paris seem to be more full of consciousness and experience than all the months of being walking, talking, faculty meeting-attending zombie back home. And by way, that 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 being in love in Paris for the first time you’ve had three double-espressos. (Laughter) That’s a fantastic way be, but it 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 to say too much about how wonderful babies are. It’s good to be a grownup. We can things like tie our shoelaces and cross the street by ourselves. And it makes sense we put a lot of effort into making babies like adults do. But if what we want is be 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 start thinking like children.
(Applause)