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 perspective of person or understand cause and effect. In the last 20 years, developmental science completely 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. thing that this baby could be thinking about, that could be going in his mind, is trying to figure out what’s going on the mind of that other baby. After all, one of the things that’s hardest all of us to do is to figure out 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 feel. Anyone who’s followed politics can testify to how hard that is for some to get. We wanted to know if babies and young children could understand this really thing about other people. Now the question is: How could ask them? Babies, after all, can’t talk, and if you ask a year-old to tell you what he thinks, what you’ll get is a stream of consciousness monologue about ponies and birthdays and things like that. So how do actually ask them the question?
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Well it turns out that secret was broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give the babies two of food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, like the crackers don’t like 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 if she the crackers and didn’t like the broccoli — just like a baby and any other sane person. half the time, what she would do is take little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she take a little bit of the crackers, and she’d go, “Eww, yuck, crackers. I the crackers. Eww, yuck.” So she’d act as if what she wanted was just the opposite what the babies wanted. We did this with 15 and 18 month-old babies. And then would simply put her hand out and say, “Can give me some?”
So the question is: What would baby give her, what they liked or what she liked? And the remarkable thing was 18 month-old babies, just barely walking and talking, would give the crackers if she liked the crackers, but they would give her the broccoli if 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 then after they stared for a time, they would just give her the crackers, what they everybody must like. So there are two really remarkable things about this. The one is that these little 18 month-old babies have discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they felt that should actually do things to help other people get what they wanted.
Even remarkably though, the fact that 15 month-olds didn’t do this suggests that 18 month-olds had learned this deep, profound fact about 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 demonstrated it.
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The question you might ask is: Why do children learn so much? And how is possible for them to learn so much in such 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 to put so much time and energy into just keeping them alive. if we turn to evolution for an answer to puzzle of why we spend so much time taking of useless babies, it turns out that there’s actually answer. If we look across many, many different species animals, not just us primates, but also including other mammals, birds, even like kangaroos and wombats, it turns out that there’s a relationship between long a childhood a species has and how big their brains are compared to their and how smart and flexible they are.
And sort the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows and other corvidae, ravens, rooks so forth, are incredibly smart birds. They’re as smart as chimpanzees in some respects. And 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 the domestic chicken. And chickens and ducks and geese and turkeys basically as dumb as dumps. So they’re very, very at 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 drop worms in their little open mouths for as long as years, which is a really long time in the life of a bird. the chickens are actually mature within a couple of months. So childhood is reason why the crows end up on the cover of Science and the chickens end up in the pot.
There’s something about that long childhood that seems be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, like chicken, seem to be beautifully suited to doing just one very well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about laws of different environments.
And of course, we beings are way out on the end of the like the crows. We have bigger brains relative to bodies by far than any other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to the world and even go to outer space. And our babies children are dependent on us for much longer than babies of any other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see this correlation? Well an idea is that that strategy, learning strategy, is an extremely powerful, great strategy for getting on the world, but it has one big disadvantage. And that one big disadvantage that, until you 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 to yourself, “A slingshot or maybe spear might work. Which would actually be better?” You want to know all that the mastodons actually show up. And the way the evolutions seems to have solved that problem is with 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. All have to do is learn. And then as adults, we can take all those things we learned when we were babies and children and actually put them 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 the protected blue sky guys who just have go out and learn and have good ideas, and we’re production and marketing. We have to take all ideas that we learned when we were children and actually put them to use. Another way of thinking it is instead of thinking of babies and children as like defective grownups, we should think about them as being a developmental stage of the same species — kind of like and butterflies — 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 this is true, if these babies are designed learn — and this evolutionary story would say children 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 in our understanding of machine learning recently. And it all depends on the ideas of this guy, Reverend Thomas Bayes, who was a statistician and mathematician in the 18th century. And what Bayes did was to provide a mathematical way using probability theory to characterize, describe, the way that find out about the world. So what scientists do is they have a hypothesis they think might be likely to start with. They go out and test it against the evidence. The makes them change that hypothesis. Then they test that new hypothesis and so on and so forth. And Bayes showed was a mathematical way that you could do that. that mathematics is at the core of the best machine learning programs that have now. And some 10 years ago, I suggested that babies be doing the same thing.
So if you want to what’s going on underneath those beautiful brown eyes, I think it actually looks like this. This is Reverend Bayes’s notebook. So I think those babies are making complicated calculations with conditional probabilities that they’re revising figure out how the world works. All right, now that seem like an even taller order to actually demonstrate. Because after all, if ask even grownups about statistics, they look extremely stupid. How it be that children are doing statistics?
So to test we used a machine that we have called the Blicket Detector. This is a that lights up and plays music when you put things on it and not others. And using this very machine, my lab and others have done 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 to put a block on top of the detector. But actually, detector works in a bit of a strange way. Because if you wave a over the top of 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 thing, put the block on the detector, it will activate two out of six times. So the unlikely actually has stronger evidence. It looks as if the waving a more effective strategy than the other strategy. So we just this; we gave four year-olds this pattern of evidence, and we just asked 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 interesting about this. The 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 give a conditional probability measure. And the other interesting thing is that they’re using that evidence to to an idea, get to a hypothesis about the world, that seems very unlikely to begin with. in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better at out an unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using to find out about the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. children do experiments we call it “getting into everything” else “playing.”
And there’s been a bunch of interesting studies recently that have shown this playing is really a kind of experimental research program. Here’s 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 and ones didn’t, and then she showed them an anomaly. And what you’ll see that this little boy will go through five hypotheses the space of two minutes.
(Video) Boy: How about this? as the other side.
Alison Gopnik: Okay, so his first hypothesis has just been falsified.
(Laughter)
Boy: one lighted up, and this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s this light up. (Laughter) I don’t know.
AG: Every scientist recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs be like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told experimenter to do this, to try putting it out onto other location. Not working either.
Boy: Oh, because the goes only to here, not here. Oh, the bottom of box has electricity 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 one to it light up and two on this one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is a particularly adorable 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 of four year-olds.
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Well, what’s it 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, lot of them have said that babies and young children were barely conscious if were conscious at all. And I think just the 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 kind of like a spotlight. So what happens for adults is we decide something’s relevant or important, we should pay attention to it. consciousness of that thing that we’re attending to becomes bright and vivid, and everything else sort of goes dark. And we even know about the way the brain does this.
So what happens we pay attention is that the prefrontal cortex, the sort of 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 have a 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 of consciousness than a spotlight of consciousness. So babies young children are very bad at narrowing down to one thing. But they’re very good at taking in lots of information from lots of sources at once. And if you actually look in their brains, you see that they’re with these neurotransmitters that are really good at inducing learning and plasticity, and inhibitory parts haven’t come on yet. So when we say that babies and young children bad at paying attention, what we really mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting that could tell them something and just looking at 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 we want to think about a way of getting a taste of kind of baby consciousness as adults, I think the best is think about cases where we’re put in a situation that we’ve never been in before — when we in love with someone new, or when we’re in new city for the first time. And what happens then not that our consciousness contracts, it expands, so that three days in Paris seem to be more full of consciousness and experience all the months of being a 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 those baby neurotransmitters. what’s it like to be a baby? It’s like in love in Paris for the first time after you’ve had double-espressos. (Laughter) That’s a fantastic way to be, but does tend to leave you waking up crying at o’clock in the morning.
(Laughter)
Now it’s good to be grownup. I don’t want to say too much about how wonderful babies are. It’s good be a grownup. We can do things like tie our shoelaces and the street by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But if we want 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 adults to thinking more like children.
(Applause)