What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would said that this baby was irrational, illogical, egocentric — that couldn’t take the perspective of another person or understand cause effect. In the last 20 years, developmental science has completely that picture. So in some ways, we think that this baby’s is like the thinking of the most brilliant scientists.
Let me give you just one example of this. thing that this baby could be thinking about, that could be going on in his mind, trying to figure out what’s going on in the mind of that other baby. After all, 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 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 and young children could this really profound 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 beautiful stream of consciousness monologue ponies 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 of raw broccoli and one bowl of delicious goldfish crackers. Now of the babies, even in Berkley, like the crackers and don’t like raw broccoli. (Laughter) But then what Betty did was take a little taste of food from each bowl. And would act as if she liked it or she didn’t. So half the time, acted as if she liked the crackers and didn’t the broccoli — just like a baby and any other person. But half the time, what she would do is take a 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 tasted crackers. Eww, yuck.” So she’d act as if what she wanted was the opposite of what the babies wanted. We did with 15 and 18 month-old babies. And then she would simply put her hand and say, “Can you give me some?”
So the is: What would the baby give her, what they or what she liked? And the remarkable thing was 18 month-old babies, just barely walking and talking, would her the crackers if she liked the crackers, but they would give her the if she liked the broccoli. On the other hand, 15 month-olds would stare at her for long time if she acted as if she liked the broccoli, they couldn’t figure this out. But then after they stared for a long time, would just give her the crackers, what they thought everybody must like. So there are two really remarkable about this. The first one is that these little 18 month-old have already discovered this really profound fact about human nature, we don’t always want the same thing. And what’s more, they felt they should actually do things to help other people get they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t do this that these 18 month-olds had learned this deep, profound fact about human nature in the months from when they were 15 months old. So both know more and learn more than we ever would have thought. this is just one of hundreds and hundreds of studies over last 20 years that’s actually demonstrated it.
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question you might ask though is: Why do children so much? And how is it possible for them to learn so in such a short time? I mean, after all, if you at babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to so much time and energy into just keeping them alive. But if we turn evolution for an answer to this puzzle of why we spend so much time taking care of babies, it turns out that there’s actually an answer. If we look across many, many species of animals, not just us primates, but also other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s a relationship how 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 the posterbirds this idea are the birds up there. On one is a New Caledonian crow. And crows and other corvidae, ravens, rooks and so forth, are smart birds. They’re as smart as chimpanzees in some respects. And this is a bird the cover of science who’s learned how to use tool to get food. On the other hand, we have friend the domestic chicken. And chickens and ducks and geese and turkeys are basically as dumb as dumps. they’re very, very good at pecking for grain, and they’re much good at doing anything else. Well it turns that the babies, the New Caledonian crow babies, are fledglings. They depend on their moms to drop in their little open mouths for as long as two years, is a really long time in the life of a bird. Whereas the chickens actually mature within a couple of months. So childhood is the reason why the crows up on the cover of Science and the chickens end up the soup pot.
There’s something about that long childhood that seems be connected to knowledge and learning. Well what kind of explanation could have for this? Well some animals, like the chicken, seem to be suited to doing just one thing very well. So they seem be beautifully suited to pecking grain in one environment. creatures, like the crows, aren’t very good at doing anything 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 distribution the crows. We have bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can learn more, we survive in more different environments, migrated to cover the world and even go to outer space. 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 into those little open mouths.
All right, why would see this correlation? Well 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 one big disadvantage is that, until you actually do that learning, you’re going to be helpless. So you don’t want to have the mastodon charging at and be saying to yourself, “A slingshot or maybe spear might work. Which would actually be better?” You want to know all before the mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind of division labor. So the idea is that we have this early period when we’re protected. We don’t have to do anything. All we have to do is learn. then as adults, we can take all those things that we learned when we babies and children and actually put them to work to do things out in the world.
So one way of thinking about it is that babies young children are like the research and development division of the human species. they’re the protected blue sky guys who just have to go out and 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 put them to use. way of thinking about it is instead of thinking of babies children as being like defective grownups, we should think them as being a different developmental stage of the same species — kind of like and butterflies — except that they’re actually the brilliant who are flitting around the garden and exploring, and we’re the caterpillars who are inching along narrow, grownup, adult path.
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If this is true, if babies are designed to learn — and this evolutionary story would 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 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 the 18th century. And essentially what Bayes did was provide a mathematical way using probability theory to characterize, describe, the way that scientists find out the world. So what scientists do is they have hypothesis that they think might be likely to start with. They go and test it against the evidence. The evidence makes change that hypothesis. Then they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way that you could do that. that mathematics is at the core of the best machine learning programs that we have now. And 10 years ago, I suggested that babies might be doing same thing.
So if you want to know what’s going on those beautiful brown eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, that might seem like an even taller order to actually demonstrate. Because after all, if ask even grownups about statistics, they look extremely stupid. How could it be that children are statistics?
So to test this we used a machine we have called the Blicket Detector. This is a box that lights up and plays music when you some things on it and not others. And using very simple machine, my lab and others have done dozens of studies showing just good babies are at learning about the world. Let me just one that we did with Tumar Kushner, my student. If I showed this detector, you would be likely to think to with that the way to make the detector go would be to put a block on top of 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 activate 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 is a more strategy than the other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked them to make it go. And sure enough, four year-olds used the evidence to wave the object on top the 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 calculations that will give them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, to a hypothesis about the world, that seems very unlikely to begin with. And in studies we’ve been 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 exactly the task. So in these circumstances, the children are using statistics find out about the world, but after all, scientists also experiments, and we wanted to see if children are doing experiments. children do experiments we call it “getting into everything” or else “playing.”
And there’s been a of interesting studies recently that have shown this playing around really a kind of experimental research program. Here’s one from Cristine Legare’s lab. What did was use our Blicket Detectors. And what she was show children that yellow ones made it go and red ones didn’t, then she showed them an anomaly. And what you’ll see is that this little boy will go through hypotheses in the space of two minutes.
(Video) Boy: about this? Same as the other side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and this 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 recognize that expression 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: Now is his next idea. He told the experimenter to do this, try putting it out onto 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, this doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So when you four. So you put four on this one to make it light up and on this 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 discovered is this is actually quite typical. If you look at the children play, when you ask them to explain something, what they do is do a series of experiments. This is actually typical of four year-olds.
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Well, what’s it like be this kind of creature? What’s it like to be of these brilliant butterflies who can test five hypotheses in two minutes? Well, you go back to those psychologists and philosophers, a lot of have said that babies and young children were barely if they 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 about how adult consciousness works. And adults’ attention and consciousness look of like a spotlight. So what happens for adults is decide that something’s relevant or important, we should pay to it. Our consciousness of that thing that we’re attending 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 a signal makes a little part of our brain much more flexible, more plastic, better at learning, and shuts down in all the rest of our brains. So we a very focused, purpose-driven kind of attention. If we look at babies young children, we see something very different. I think babies and young children seem to have of a lantern of consciousness than a spotlight of consciousness. So babies and young children are very bad at down to just one thing. But they’re very good at taking in lots information from lots of different sources at once. And if you actually look in brains, you see that they’re flooded with these neurotransmitters that are really good at learning and plasticity, and the inhibitory parts haven’t come on yet. So when we say babies and young children are bad at paying attention, what we really is that they’re bad at not paying attention. So they’re bad getting rid of all the interesting things that could tell them something and just looking the thing that’s important. That’s the kind of attention, the kind consciousness, that we might expect from those butterflies who are to learn.
Well if we want to think about a way of getting a taste of that kind baby consciousness as adults, I think the best thing think about cases where we’re put in a new situation that we’ve been in before — when we fall in love with new, or when we’re in a new city for the first time. what happens then is not that our consciousness contracts, it expands, so that three days in Paris seem to be more full of consciousness and experience than all the months 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 to be a baby? It’s like being in love in Paris for the first time after you’ve 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. don’t want to say too much about how wonderful babies are. It’s to be a grownup. We can do things like tie our shoelaces and cross the street by ourselves. it makes sense that we put a lot of effort into babies think like adults do. But if what we want is to be like butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be getting the adults to start more like children.
(Applause)