What going on in this baby’s mind? If you’d asked this 30 years ago, most people, including psychologists, would have said that baby was irrational, illogical, egocentric — that he couldn’t take the perspective another person or understand cause and effect. In the last 20 years, developmental science has overturned that picture. So in some ways, we think that this baby’s thinking is the thinking of the most brilliant scientists.
Let me give you one example of this. One thing that this baby be thinking about, that could be going on in mind, is trying to figure out what’s going on in the mind 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 hardest thing of all to figure out that what other people think and feel isn’t actually like what we think and feel. Anyone who’s followed politics can testify to how hard that for some people to get. We wanted to know if babies young children could understand this really profound thing about other people. the question is: How could we ask them? Babies, after all, can’t talk, if you ask a three year-old to tell you what thinks, what you’ll get is a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how do we ask them the question?
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Well it turns out the secret was broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give the two 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) then what Betty did was to take a little of food from each bowl. And she would act as she liked it or she didn’t. So half the time, acted as if she liked the crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what she would is take 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.” So she’d 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 you give me some?”
So question is: What would the baby give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just barely walking and talking, would give the crackers if she liked the crackers, but they give her the broccoli if she liked the broccoli. the other hand, 15 month-olds would stare at her for a long time if acted as if she liked the broccoli, like they couldn’t figure this out. then after they stared for a long time, they would just give her the crackers, what they thought must like. So there are two really remarkable things this. The first one is that these little 18 month-old babies have already this really profound fact about human nature, that we don’t always want the thing. And what’s more, they felt that they should actually do things to help other people get they 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 were 15 old. So children both know more and learn more than we would have thought. And this is just one of and hundreds of studies over the last 20 years that’s actually demonstrated it.
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question you might ask though is: Why do 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 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 we spend so much time taking care of useless babies, turns out that 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 kangaroos and wombats, it turns out that there’s a relationship how long a childhood a species has and how their brains are compared to their bodies and how and flexible they are.
And sort of the posterbirds for this idea are the birds there. On one side is a New Caledonian crow. crows and other corvidae, ravens, rooks and so forth, incredibly smart birds. They’re as smart as chimpanzees in some respects. And is a bird 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 geese and turkeys are basically as dumb as dumps. So they’re very, very good at for grain, and they’re not much good at doing anything else. it turns out that the babies, the New Caledonian crow babies, fledglings. They depend on their moms to drop worms in their little mouths for as long as two years, which is a really long time in the life a bird. Whereas the chickens are actually mature within a couple of months. So childhood is reason why the crows end up on the cover Science and the chickens end up in the soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what kind of explanation we have for this? Well some animals, like the chicken, to be beautifully suited to doing just one thing well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t very at doing anything in particular, but they’re extremely good at about laws of different environments.
And of course, we human beings are out on the end of the distribution like the crows. We have bigger relative to our 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 cover the world even go to outer space. And our babies and children are dependent on us for much longer than babies of any other species. My son is 23. (Laughter) at least until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it has one big disadvantage. And that one big is that, until you actually do all that learning, you’re to be helpless. So you don’t want to have the mastodon charging you and be saying to yourself, “A slingshot or maybe a might work. Which would actually be better?” You want to know all before the mastodons actually show up. And the way 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. we have to do is learn. And then as adults, we take all those things that we learned when we were and children and actually put them to work to things out there in the world.
So one way of thinking about is that babies and young children are like the research and development of the human species. So they’re the protected blue sky guys who just have to out and 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 them to use. Another way of thinking about it is instead of of babies and children as being like defective grownups, we should think about them as a different developmental stage of the same species — kind of caterpillars and butterflies — except that they’re actually the brilliant butterflies who are flitting the garden and exploring, and we’re the caterpillars who are inching our narrow, grownup, adult path.
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If this 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 they would have really powerful learning mechanisms. And in fact, the baby’s brain seems be the most powerful learning computer on the planet. But computers are actually getting to be a lot better. there’s been a revolution in our understanding of machine recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician and mathematician the 18th century. And essentially what Bayes did was to provide a way using probability theory to characterize, describe, the way scientists find out about the world. So what scientists 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 hypothesis and so on and so forth. And what Bayes showed was mathematical way that you could do that. And that mathematics is at core of the best machine learning programs that we have now. some 10 years ago, I suggested that babies might be the same thing.
So if you want to know what’s going underneath those beautiful brown eyes, I think it actually looks something this. This is Reverend Bayes’s notebook. So I think those babies are actually making complicated calculations with conditional that they’re revising to figure out how the world works. All right, now might seem like an even taller order to actually demonstrate. Because after all, you ask even grownups about statistics, they look extremely stupid. How could it be children are doing statistics?
So to test this we a machine that we have called the Blicket Detector. is a box that lights up and plays music you put some 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 at learning about world. Let me mention just one that we did Tumar Kushner, my student. If I showed you this detector, you would likely to think to begin with that the way to make the detector would be to put a block on top of detector. But actually, this detector works in a bit of a strange way. if you wave a block over the top of the detector, something wouldn’t ever think of to begin with, the detector actually activate two out of three times. Whereas, if you do the likely thing, put block on the detector, it will only activate two out of six times. the unlikely hypothesis actually has stronger evidence. It looks as if waving is a more effective strategy than the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just asked them to make it go. sure enough, the four year-olds used the evidence to 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 year-olds. They’re just learning how to count. But unconsciously, they’re doing quite complicated calculations that will give them a conditional probability measure. And the other thing is that they’re using that evidence to get to an idea, get a hypothesis about the world, that seems very unlikely to begin with. And studies we’ve just been doing in my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are statistics to find out about the world, but after all, also do experiments, and we wanted to see if children are doing experiments. When children do experiments call it “getting into everything” or else “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 was use our Blicket Detectors. And what she did was show children that yellow made it go and red ones didn’t, and then showed them an anomaly. And what you’ll see is that this little boy will go through five hypotheses the space of two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis just been falsified.
(Laughter)
Boy: This one lighted up, and 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 will that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, and this to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: this is 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 has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s fourth hypothesis.
Boy: It’s lighting up. So when you put four. you put four on this one to make it up and two on this one to make it up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, but Cristine discovered is this is actually quite typical. If look at the way children play, when you ask them to explain something, what they do is 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 be one of these brilliant who can test five hypotheses in two minutes? Well, if you go back to psychologists and philosophers, a lot of them have said that babies young children were barely conscious if they were conscious at all. And I think just opposite is 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. And adults’ attention consciousness look kind of like a spotlight. So what for adults is we decide that something’s relevant or important, we should attention to it. Our consciousness of that thing that we’re attending to becomes extremely bright and vivid, and else sort of goes dark. And we even know something about way the brain does this.
So what happens when we attention is that the prefrontal cortex, the sort of executive part our brains, sends a signal that makes a little part of our brain more flexible, more plastic, better at learning, and shuts down activity in all the rest of brains. So we have a very focused, purpose-driven kind of attention. we look at babies and young children, we see something very different. I think and young children seem to have more of a lantern consciousness than a spotlight of consciousness. So babies and young children are very bad at narrowing down to one thing. But they’re very good at taking in of information from lots of different sources at once. And if you actually look in their brains, see that they’re flooded with these neurotransmitters that are really good 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 they’re bad at not 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 kind of attention, the kind of consciousness, that we might from those butterflies who are designed to learn.
Well if we want to think a way of getting a taste of that kind of baby consciousness adults, I think the best thing is think about cases 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. what happens then is not that our consciousness contracts, expands, so that those three days in Paris seem to be more full of consciousness and experience than the months of being a walking, talking, faculty meeting-attending zombie back home. by the way, that coffee, that wonderful coffee you’ve been drinking downstairs, mimics the effect of those baby neurotransmitters. So what’s it like be a baby? It’s like being in love in for the first time after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it 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 want to say 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 we put a lot of effort into making think like adults do. But if what we want is to be like 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)