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 person or understand cause and effect. In the last 20 years, developmental science has completely overturned that picture. in some ways, we think that this baby’s thinking is like the of the most brilliant scientists.
Let me give you just one example of this. One thing 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 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 the hardest thing of all is to figure out that what other think and feel isn’t actually exactly like what we think feel. Anyone who’s followed politics can testify to how that is for some people to get. We wanted know if babies and young children could understand this really thing about other people. Now the question is: How could we them? Babies, after all, can’t talk, and if you ask a three year-old to you what he thinks, what you’ll get is a beautiful 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 out that the secret was broccoli. What we did — Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, like the and don’t like the raw broccoli. (Laughter) But then what Betty did to take a little taste of food from each bowl. And she act 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. But the time, what she would do is take a little bit of the broccoli go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take little bit of the crackers, and she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d act if what she wanted was just the opposite of the babies wanted. We did this with 15 and 18 month-old babies. And she would simply put her hand out and say, “Can give me some?”
So the question is: What would the baby her, what they liked or what she liked? And remarkable thing was that 18 month-old babies, just barely and talking, would give her the crackers if she the crackers, but they would give her the broccoli she liked the broccoli. On the other hand, 15 month-olds would stare her for a long time if she acted as if she liked the broccoli, like they couldn’t this out. But then after they stared for a long time, they would just her the crackers, what they thought everybody must like. So there are really remarkable things about this. The first one is that little 18 month-old babies have already discovered this really fact about human nature, that we don’t always want same thing. And what’s more, they felt that they should actually do things to help other people what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds had this deep, profound fact about human nature in the three months from when were 15 months old. So children both know more and learn more than we would have thought. And this is just one of hundreds and hundreds of studies over the 20 years that’s actually demonstrated it.
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The you might ask though is: Why do children learn much? And how is it possible for them to learn so much in such a short time? mean, after all, if you look at babies superficially, seem pretty useless. And actually in many ways, they’re worse than useless, because we to put so much time and energy into just keeping alive. But if we turn to evolution for an answer to this puzzle of why spend so much time taking care of useless babies, it turns out there’s actually an answer. If we look across many, many different species animals, not just us primates, but also including other mammals, birds, even marsupials like 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 bodies how smart and flexible they are.
And sort of 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 birds. They’re as smart as chimpanzees in some respects. And this is a bird on cover of science who’s learned how to use a to get food. On the other hand, we have our friend domestic chicken. And chickens and ducks and geese and are basically as dumb as dumps. So they’re very, very at pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, New Caledonian crow babies, are fledglings. They depend on moms to drop worms in their little open mouths for as long two years, which is a really long time in the of a bird. Whereas the chickens are actually mature within a couple of months. childhood is the reason why the crows end up on the cover of Science and chickens end up in the soup pot.
There’s something about long childhood that seems to be connected to knowledge and learning. Well what kind of explanation could have for this? Well some animals, like the chicken, seem to be beautifully suited to just one thing very well. So they seem to beautifully suited to pecking grain 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 course, we human beings are way out on the end of the distribution the crows. We have bigger brains relative to our bodies by than any other animal. We’re smarter, we’re more flexible, we learn more, we survive in more different environments, we migrated to cover the world and even go outer space. And our babies and children are dependent on us for longer than the babies 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, would we see this correlation? Well an idea is that strategy, that learning strategy, is an extremely powerful, great strategy for getting on in the world, but has one big disadvantage. And that one big disadvantage is that, until you actually all that learning, you’re going to be helpless. So you don’t want to have the mastodon charging you and be saying to yourself, “A slingshot or maybe a spear work. Which would actually be better?” You want to know all that before mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind of division of labor. So the idea is we 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, can take all those things that we learned when we were babies and and actually put them to work to do things out in the world.
So one way of thinking about it is that babies and children are like the research and development division of human species. So they’re the protected 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 ideas that we when we were children and actually put them to use. Another way of about it is instead of thinking of babies and children as being like grownups, we should think about them as being a different developmental stage of the same species — kind like caterpillars 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 is true, if these babies are designed to learn — and evolutionary story would say children are 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 to be the most powerful learning on the planet. But real computers are actually getting to be a lot better. And there’s been a in our understanding of machine learning recently. And it all depends on ideas of this guy, the Reverend Thomas Bayes, who was a statistician mathematician in the 18th century. And essentially what Bayes did was provide a mathematical way using probability theory to characterize, describe, way that scientists find out about the world. So scientists do is they have a hypothesis that they think might be likely start with. They go out and test it against evidence. The evidence makes them change that hypothesis. Then they test that new and so on and so forth. And what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of the best learning programs that we have now. And some 10 years ago, I that babies might be doing the same thing.
So if you to know what’s going on underneath those beautiful brown eyes, think it actually looks something like this. This is Bayes’s notebook. So I think those babies are actually complicated calculations with conditional probabilities that they’re revising to out how the world works. All right, now that might seem like an even taller order actually 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 machine that we have called Blicket Detector. This is a box that lights up and plays music when you put things on it and not others. And using this very simple machine, my and others have done dozens of studies showing just how good babies are learning about the world. Let me mention just one that we did Tumar Kushner, my student. If I showed you this detector, you would be likely to think to begin with the way to make the detector go would be to put a block on of the detector. But actually, this detector works in a bit of a strange way. Because you wave a block over the top of the detector, something you wouldn’t think of to begin with, the detector will actually two out of three times. Whereas, if you do the likely thing, put the 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 the other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked them to it go. And sure enough, the four year-olds used the evidence wave the object on top of the detector.
Now there are two that are really interesting about this. The first one is, again, remember, these are four year-olds. They’re just learning to count. But unconsciously, they’re doing these quite complicated calculations that give them a conditional probability measure. And the other thing is that they’re using that evidence to get to an idea, get to hypothesis about the world, that seems very unlikely to begin with. And in studies we’ve just doing in my lab, similar studies, we’ve show that four year-olds are better at finding out an unlikely hypothesis than adults are when we give them the same task. So in these circumstances, the children are statistics to find out about the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. When children do experiments we it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown this around is really a kind of experimental research program. Here’s one Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. And what she was show children that yellow ones made it go and red ones didn’t, and then she showed them anomaly. And what you’ll see is that this little boy will go through hypotheses in the space of two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis has just falsified.
(Laughter)
Boy: This one lighted up, and this one nothing.
AG: Okay, he’s his experimental notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every will 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 the other location. working either.
Boy: Oh, because the light goes only here, not here. Oh, the bottom of this box has in here, but this doesn’t have electricity.
AG: Okay, that’s a hypothesis.
Boy: It’s lighting up. So when you put four. So you put on this one to make it light up and two on one 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 is this is actually quite typical. If you look the way children play, when you ask them to 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 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 those psychologists and philosophers, a lot of them have said that babies and young children were conscious if they were conscious at all. And I think just the opposite is true. think babies and children are actually more conscious than we are adults. Now here’s what we know about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens for is we decide that something’s relevant or important, we should pay to it. Our consciousness of that thing that we’re attending to becomes extremely bright vivid, and everything else sort of goes dark. And we know something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, the sort of executive of our brains, sends a signal that makes a part of our brain much more flexible, more plastic, better at learning, and shuts down activity in all rest of our brains. So we have a very focused, purpose-driven kind of attention. we look at babies and young children, we see very different. I think babies and young children seem to have more a lantern 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 from lots of different sources at once. And if you look in their brains, you see that they’re flooded with these neurotransmitters 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 are bad paying attention, what we really mean is that they’re at not paying attention. So they’re bad at getting rid of the interesting things that could tell them something and just at the thing that’s important. That’s the kind of attention, the of consciousness, that we might expect from those butterflies who are to learn.
Well if we want to think about way of getting a taste of that kind of consciousness as adults, I think the best thing is think cases where we’re put in a new situation that we’ve never been before — when we fall in love with someone new, when we’re in a new city for the first time. And what happens then is not that our contracts, it expands, so that those three days in Paris seem to be more full of consciousness experience than all the months of being a walking, talking, faculty meeting-attending zombie home. And by the way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics effect of those baby neurotransmitters. So what’s it like be a baby? It’s like being in love in Paris the first time after you’ve had three double-espressos. (Laughter) That’s fantastic way to be, but it does tend to you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s good to a 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 a lot 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 we should be getting the adults to start thinking like children.
(Applause)