What is going on in this baby’s mind? If you’d people this 30 years ago, most people, including psychologists, would said that this baby was irrational, illogical, egocentric — that he couldn’t take perspective of another person or understand cause and effect. In last 20 years, developmental science has completely overturned that picture. So in some ways, think that this baby’s thinking is like the thinking the most brilliant scientists.
Let me give you just one of this. One thing that this baby could be thinking about, that could be on in his mind, is trying to figure out what’s going on in the mind of that other baby. all, one of the things that’s hardest for all of us to do is to figure what other people are thinking and 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 followed politics can to how hard that is for some people to get. wanted to know if babies and young children could understand this really profound thing about other people. Now question is: How could we ask them? Babies, after all, can’t talk, and if you ask a three year-old tell you what he thinks, what you’ll get is a beautiful stream of consciousness monologue about and birthdays and things like that. So how do we actually ask the question?
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Well it turns out that the secret broccoli. What we did — Betty Rapacholi, who was one of my students, and I — was to give the babies two bowls of food: one bowl raw broccoli and one bowl of delicious goldfish crackers. all of the babies, even in Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But 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 the crackers and didn’t like the broccoli — just like a and any other sane person. But half the time, what she would do take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then would take a little 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 this with 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? And the remarkable was that 18 month-old babies, just barely walking and talking, would give her the if she liked the crackers, but they would give her broccoli if she liked the broccoli. On the other hand, 15 month-olds would at her for a long time if she acted as if she the broccoli, like they couldn’t figure this out. But after they stared for a long time, they would give her the crackers, what they thought everybody must like. So there are two remarkable things about this. The first one is that little 18 month-old babies have already discovered this really profound fact human nature, that we don’t always want the same thing. what’s more, they felt that they should actually do things help other people get what they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t do suggests that these 18 month-olds had learned this deep, profound fact about human nature in three months from when they were 15 months old. So children both know and learn more than we ever would have thought. And this is just one of and hundreds of studies over the last 20 years that’s actually 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 so much in a short time? I mean, after all, if you look at superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, we have to put so much time and energy into keeping them alive. But if we turn to evolution for an answer to this of why we spend so much time taking care of useless babies, turns out that there’s actually an answer. If we across many, many different species of animals, not just us primates, but including other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s a relationship between how a childhood a species has and how big their are compared to their bodies and how smart and flexible they are.
And sort of posterbirds for this idea are the birds up there. On side is a New Caledonian crow. And crows and corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re smart as chimpanzees in some respects. And this is a on the cover of science who’s learned how to use a tool to get food. On the hand, we have our friend the domestic chicken. And chickens ducks and geese and turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much good at doing else. Well it turns out that the babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little open mouths for long as two years, which is a really long in the life of a bird. Whereas the chickens actually mature within a couple of months. So childhood is the reason the crows end up on the cover of Science the chickens end up in the soup pot.
There’s something about long childhood that seems to be connected to knowledge and learning. what kind of explanation could we have for this? some animals, like the chicken, seem to be beautifully to doing just one thing very well. So they seem to be 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 learning about laws of different environments.
And of course, we human beings are way on the end of the distribution like the crows. We have bigger brains relative to our bodies by than any other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to cover the world and even go to space. And our babies and children are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into those little open mouths.
All right, why we see this correlation? Well an idea is that that strategy, that learning strategy, is extremely powerful, great strategy for getting on in the world, but it one big disadvantage. And that one big disadvantage is that, until actually do all that learning, you’re going to be helpless. So don’t want to have the mastodon charging at you and be saying yourself, “A slingshot or maybe a spear might work. Which actually be better?” You want to know all that before the mastodons show up. And the way the evolutions seems to have solved that problem with a kind of division of labor. So the idea is that have this early period when we’re completely protected. We don’t have to do anything. we have to do is learn. And then as adults, we can take all things that we learned when we were babies and children and actually put them to to do things out there in the world.
So one way of about it is that babies and young children are like the research development division of the human species. So they’re the blue sky guys who just have to go out and learn and have good ideas, and we’re production marketing. We have to take all those ideas that we learned when we were children and actually them to use. Another way of thinking about it is instead of thinking of babies and as being like defective grownups, we should think about as being a different developmental stage of the same — kind of like caterpillars and butterflies — except that they’re the brilliant butterflies who are flitting around the garden and exploring, we’re the caterpillars who are inching along our narrow, grownup, adult path.
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If is true, if these babies are designed to learn — and this story would say children are for learning, that’s what they’re — we might expect that they would have really learning mechanisms. And in fact, the baby’s brain seems to the most powerful learning computer on the planet. But real computers actually getting to be a lot better. And there’s a revolution in our understanding of machine learning recently. 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 did was to provide a mathematical way probability theory to characterize, describe, the way that scientists find out about the world. So what do is they have a hypothesis that they think be likely to start with. They go out and test it against the evidence. The makes them change that hypothesis. Then they test that hypothesis and so on and so forth. And what showed was a mathematical way that you could do that. And that is at the core of the best machine learning that we have now. And some 10 years ago, I suggested that babies might doing the same thing.
So if you want to what’s going on underneath those beautiful brown eyes, I think it looks something like this. This is Reverend Bayes’s notebook. 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 taller order actually demonstrate. Because after all, if you ask even grownups about statistics, look extremely stupid. How could it be that children are doing statistics?
So test this we used a machine that we have 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 done dozens studies showing just how good babies are at learning the world. Let me mention just one that we with Tumar Kushner, my student. If I showed you detector, you would be likely to think to begin with the way to make the detector go would be to put a block on top 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 begin with, the will actually activate two out of three times. Whereas, if you do the thing, put the block on the detector, it will only activate two of six times. So the unlikely hypothesis actually has evidence. It looks as if the waving is a more effective strategy than the other strategy. So we just this; we gave four year-olds this pattern of evidence, and we just them to make it go. And sure enough, the four year-olds 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 how to count. But unconsciously, they’re doing these quite complicated calculations that will them a conditional probability measure. And the other interesting thing is that they’re using that to get to an idea, get to a hypothesis about the world, that seems unlikely to begin with. And in studies we’ve just doing in my lab, similar studies, we’ve show that four year-olds are actually better at finding an unlikely hypothesis than adults are when we give them the same task. So in these circumstances, the children are using statistics to out about the world, but after all, scientists also do experiments, and we to see if children are doing experiments. When children do 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 experimental program. Here’s one from Cristine Legare’s lab. What Cristine 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 anomaly. And what you’ll see is that this little boy go through five hypotheses in the space of two minutes.
(Video) Boy: How this? Same as the other side.
Alison Gopnik: Okay, so his first hypothesis just been falsified.
(Laughter)
Boy: This one lighted up, and this 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 be like this, this needs to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this his next idea. He told the experimenter to do this, to try putting it out the 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, but this doesn’t 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 and two on this one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is a adorable and articulate little boy, but what Cristine discovered is this actually quite typical. If you look at the way children play, when you ask to explain 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 like to be this kind of creature? What’s it to be one of these brilliant butterflies who can five hypotheses in two minutes? Well, if 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 we are as adults. Now here’s what we know about how adult consciousness works. And adults’ attention consciousness look kind of like a spotlight. So 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 goes dark. And we even know something about the the brain does 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 part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven kind of attention. If we look at and young children, we see something very different. I think and young children seem to have more of a lantern of consciousness a spotlight of consciousness. So babies and young children are bad at narrowing down to just one thing. But they’re good at taking in lots of information from lots of different sources once. And if you actually look in 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 say that babies and young children are bad at paying attention, what really mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting things that could them something and just looking at the thing that’s important. That’s kind of attention, the kind of consciousness, that we might from those butterflies who are designed to learn.
Well if we want to think about way of getting a taste of that kind of baby consciousness as adults, I the best thing is think about cases where we’re in a new situation that we’ve never been in before — when we fall in with someone new, or when we’re in a new city for the time. And what happens then is not that our consciousness contracts, expands, so that those three days in Paris seem to be more full of and 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 effect of those baby neurotransmitters. So what’s it like to be baby? It’s like being in love in Paris for the first time you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it does 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 babies are. It’s good to be grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that put a lot of effort into making babies think like adults do. But if what want is to be like those butterflies, to have open-mindedness, learning, imagination, creativity, innovation, maybe at least some of the time we should getting the adults to start thinking more like children.
(Applause)