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 couldn’t take the perspective of another person or understand cause and effect. In the 20 years, developmental science has completely overturned that picture. So in some ways, think that this baby’s thinking is like the thinking of the brilliant scientists.
Let me give you just one example of this. One that this baby could be thinking about, that could going on in his mind, is trying to figure out what’s going in the mind of that other baby. After all, one of the that’s hardest for all of us to do is to figure out 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 actually exactly what we think and feel. Anyone who’s followed politics can testify to how hard that is for some to get. We wanted to know if babies and children could understand this really profound thing about other people. Now the is: How could we ask 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 stream of consciousness monologue about ponies and birthdays things like that. So how do we actually ask them the question?
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Well it out that the secret was broccoli. What we did — Betty Rapacholi, who was of my students, and I — was actually to give the babies bowls of food: one bowl of raw broccoli and one bowl delicious goldfish crackers. Now all of the babies, even in Berkley, the crackers and don’t like the raw broccoli. (Laughter) But what Betty did was to take a little taste of food from bowl. And she would act as if she liked it she didn’t. So half the time, she acted as she liked the crackers and didn’t like the broccoli — just like a baby and other sane person. But half the time, what she would do is a little bit of the broccoli and go, “Mmmmm, broccoli. 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.” she’d act as if what she wanted was just the opposite what the babies wanted. We did this with 15 18 month-old babies. And then she would simply put hand out and say, “Can you give me some?”
So the question is: What the baby give her, what they liked or what liked? And the remarkable thing was that 18 month-old babies, just barely walking and talking, would her the crackers if she liked the crackers, but they would give the broccoli if she liked the broccoli. On the hand, 15 month-olds would stare at her for a long if she acted as if she liked the broccoli, they couldn’t figure this out. But then after they stared for long time, they would just give her the crackers, what thought everybody must like. So there are two really remarkable about this. The first one is that these little 18 month-old babies have already discovered this really fact about human nature, that we don’t always want the thing. And what’s more, they felt that they should actually do to help other people get what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds had learned this deep, profound about human nature in the three months from when they were 15 months old. So both know more and learn more than we ever would have thought. And this is just one hundreds and hundreds of studies over the last 20 years that’s demonstrated it.
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The question you might ask though is: Why children learn so much? And how is it possible for to learn so much in such a short time? I mean, after all, you look at babies superficially, they seem pretty useless. actually in many ways, they’re worse than useless, because have to put so much time and energy into just them alive. But if we turn to evolution for an answer to this puzzle why we spend so much time taking care of useless babies, it out that there’s actually an answer. If we look across many, different species of animals, not just us primates, but also other mammals, birds, even marsupials like kangaroos and wombats, it turns that there’s a relationship between how long a childhood a species has how big their brains are compared to their bodies and how smart and flexible they are.
And of the posterbirds for this idea are the birds there. On one side is a New Caledonian crow. And crows and other corvidae, ravens, rooks and forth, are incredibly smart birds. They’re as smart as chimpanzees in some respects. And this is a on the cover of science who’s learned how to a tool to get food. On the other hand, have our friend the domestic 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 that the babies, the New crow babies, are fledglings. They depend on their moms to drop worms in their little mouths for as long as two years, which is a long time in the life of a bird. Whereas the chickens are actually mature within a couple months. So childhood is the reason why the crows up on the cover of Science and the chickens end in the soup pot.
There’s something about that long childhood seems to be connected to knowledge and learning. Well what kind of explanation could we for this? Well some animals, like the chicken, seem to be beautifully to doing just one thing very well. So they seem to be beautifully suited to pecking grain one environment. Other creatures, like the crows, aren’t very at doing anything in particular, but they’re extremely good learning about laws of different environments.
And of course, we human beings way out on the end of the distribution like crows. We have bigger brains relative to our bodies by far than 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 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 worms into those little open mouths.
All right, why we see this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting in the world, but it has one big disadvantage. that one big disadvantage is that, until you actually all that learning, you’re going to be helpless. So you don’t want to the mastodon charging at you and be saying to yourself, “A or maybe a spear might work. Which would actually better?” You want to know all that before the actually show up. And the way the evolutions seems to have that problem is with a kind of division of labor. So the is that we have this early period when we’re protected. We don’t have to do anything. All we to do is learn. And then as adults, we can take all those things that we when we were babies and children and actually put them to to do things out there in the world.
So one of thinking about it is that babies and young children are like the research development division of the human species. So they’re the protected blue sky guys who just to go out and learn and have good ideas, and we’re production and marketing. We have take all those ideas that we learned when we were and actually put them to use. Another way of thinking about it is of thinking of babies and children as being like defective grownups, we should think them as being a different developmental stage of the species — kind of like caterpillars and butterflies — that they’re actually the brilliant butterflies who are flitting the garden and exploring, and we’re the caterpillars who are along our narrow, grownup, adult path.
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If this true, if these babies are designed to learn — and this story would say children are for learning, that’s what they’re for — we might expect that they would 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 getting to be a lot better. And there’s been revolution in our understanding of machine learning recently. And it all depends the ideas of this guy, the Reverend Thomas Bayes, who was a statistician and mathematician in 18th century. And essentially what Bayes did was to provide a way using probability theory to characterize, describe, the way that find out about the world. So what scientists do is have a hypothesis that they think might be likely start with. They go out and test it against the evidence. evidence makes them change that hypothesis. Then they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of the best machine programs that we have now. And some 10 years ago, I that babies might be doing the same thing.
So if want to know what’s going on underneath those beautiful brown eyes, I it actually looks something like this. This is Reverend Bayes’s notebook. So I think those babies are actually making calculations with conditional probabilities that they’re revising to figure how the world works. All right, now that might like an even taller order to actually demonstrate. Because all, if you ask even grownups about statistics, they look extremely stupid. could it be that children are doing statistics?
So test this we used a machine that we have called the Blicket Detector. This is a box lights up and plays music when you put some on it and not others. And using this very machine, my lab and others have done dozens of showing just how good babies are at learning about the world. Let me mention just one that we with Tumar Kushner, my student. If I showed you this detector, you would be likely to to begin with that 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 strange way. Because if you wave a block over top of the detector, something you wouldn’t ever think to begin with, the detector will actually activate two of three times. Whereas, if you do the likely thing, put the block on the detector, it only activate two out of six times. So the hypothesis actually has stronger evidence. It looks as if the waving is a more effective strategy than the strategy. So we did just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And sure enough, the four year-olds used the evidence wave the object on top of the detector.
Now there are two things are really interesting about 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 give them a conditional probability measure. And the other interesting thing is that they’re that evidence to get to an idea, get to a hypothesis the world, that seems very unlikely to begin with. And in we’ve just been doing in my lab, similar studies, we’ve show that four year-olds are actually better finding out an unlikely hypothesis than adults are when give them exactly the same task. So in these circumstances, the children are statistics to find out about the world, but after all, scientists also do experiments, and we wanted to see children are doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of interesting studies recently that have this playing around is really a kind of experimental program. Here’s one from Cristine Legare’s lab. What Cristine did use our Blicket Detectors. And what she did was children that yellow ones made it go and red ones didn’t, then she showed them an anomaly. And what you’ll see that this little boy will go through five hypotheses in space of two minutes.
(Video) Boy: How about this? as the other side.
Alison Gopnik: Okay, so his first has just 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 light up. (Laughter) I don’t know.
AG: scientist will recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to 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 the experimenter to do this, to try putting it out onto the other location. working either.
Boy: Oh, because the light goes only to here, not here. Oh, the bottom of this has electricity in here, but this doesn’t have 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 this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that a particularly adorable and articulate little boy, but what discovered is this is 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. is actually pretty typical of four year-olds.
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Well, what’s it like to be this of creature? What’s it like to be one of these brilliant butterflies who can test five hypotheses two minutes? Well, if you go back to those psychologists and philosophers, a of them have said that babies and young children were barely conscious if they conscious at all. And I think just the opposite true. I think babies and children are actually more than we are as adults. Now here’s what we know about how adult consciousness works. adults’ attention and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant or important, we should pay to it. Our consciousness of that thing that we’re to becomes extremely bright and vivid, and everything else sort goes dark. And we even know something about the the brain does this.
So what happens when we attention is that the prefrontal cortex, the sort of executive part of our brains, sends signal that makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in all the rest of our brains. we have a very focused, purpose-driven kind of attention. If look at babies and young children, we see something very different. I babies and 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 to just one thing. But they’re very good at taking in lots information from lots of different sources at once. And if you look in their brains, you see that they’re flooded these neurotransmitters that are really good at inducing learning and plasticity, the inhibitory parts haven’t come on yet. So when we say that babies and children are 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 might expect those butterflies who are designed to learn.
Well if want to think about a way of getting a of that kind of baby consciousness as adults, I the best thing is think about cases where we’re put in a new that we’ve never been in before — when we fall in love someone new, or when we’re in a new city for the 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 and than all the months of being a walking, talking, faculty meeting-attending zombie back home. by the way, that coffee, that wonderful coffee you’ve been downstairs, actually mimics the effect of those baby neurotransmitters. So what’s like to be a baby? It’s like being in 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 a grownup. I don’t want to too much about how wonderful babies are. It’s good to a grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But if what we want is to like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of the time we be getting the adults to start thinking more like children.
(Applause)