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 another person or cause and effect. In the last 20 years, developmental has 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. One thing that baby could be thinking about, that could be going on in mind, is trying to figure out what’s going on the mind of that other baby. After all, one of things that’s hardest for all of us to do to figure out what other people are thinking and feeling. maybe the hardest thing of all is to figure out that what other people 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 to know if babies and young could understand this really profound thing about other people. Now the question is: could we ask them? Babies, after all, can’t talk, and you ask a three year-old to tell you what he thinks, what you’ll is a beautiful 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 that the 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 delicious goldfish crackers. Now all of babies, even in Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But then what Betty was to take a little taste of food from each bowl. she would act as if she liked it or she didn’t. half the time, she acted as if she liked the crackers and didn’t 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 and go, “Mmmmm, broccoli. tasted the broccoli. Mmmmm.” And then she would take a little bit the crackers, and she’d go, “Eww, yuck, crackers. I tasted crackers. Eww, yuck.” So she’d act as if what wanted was just the opposite of what the babies wanted. We this with 15 and 18 month-old babies. And then she would put her hand out and say, “Can you give me some?”
So the question is: What would baby give her, what they liked or what she liked? And the remarkable thing that 18 month-old babies, just barely walking and talking, would give the crackers if she liked the crackers, but they would her the broccoli if 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 broccoli, like 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 are two really remarkable things about this. The first one that these little 18 month-old babies have already discovered this profound fact about human nature, that we don’t always want same thing. And what’s more, they felt that they actually do things to help other people get what 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 they were 15 months old. So children both know and learn more than we ever would have thought. And this is one of 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 do learn so much? And how is it possible for them to so much in such a short time? I mean, after all, if you look at superficially, they seem pretty useless. And 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 this puzzle of why we spend so much time care of useless babies, it turns out that there’s actually an answer. If look across many, many different species of animals, not just us primates, but also including other mammals, birds, marsupials like kangaroos and wombats, it turns out that there’s relationship between how long a childhood a species has how big their brains are compared to their bodies and smart and flexible they are.
And sort of the posterbirds for this idea the birds up there. On one side is a Caledonian crow. And crows and other corvidae, ravens, rooks so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird on the cover of who’s learned how to use a 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 not much good at doing anything else. Well turns out that the babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little mouths for as long as two years, which is really long time in the life of a bird. the chickens are actually mature within a couple of months. So childhood the reason why the crows end up on the cover of Science and chickens end up in the soup pot.
There’s something about that long childhood that seems be connected to knowledge and learning. Well what kind of 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 grain in 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 our by far than any other animal. We’re smarter, we’re more flexible, we can learn more, survive in more different environments, we migrated to cover the world and even go to outer space. And babies and children are dependent on us for much longer than the babies any other species. My son is 23. (Laughter) And least 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 strategy, that learning strategy, is an extremely powerful, great strategy for on in the world, but it has one big disadvantage. And that one disadvantage is that, until you actually do all that learning, you’re going be helpless. So you don’t want to have the charging at you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” You want to all that before the mastodons actually show up. And the way the seems to have solved that problem is with a kind division of labor. So the idea is that we this early period when we’re completely protected. We don’t have do anything. All we have to do is learn. And then as adults, we can take those things that we learned when we were babies and and actually put them to work to do things there 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 have to go out and learn and have good ideas, we’re production and marketing. We have to take all those ideas that we learned when we were and actually put them to use. Another way of thinking about it is instead of thinking of and children as being like defective grownups, we should think about as being a different developmental stage of the same — kind of like caterpillars and butterflies — except that they’re actually the brilliant butterflies who flitting around the garden and exploring, and we’re the caterpillars who inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to learn — this 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, baby’s brain seems to be the most powerful learning on the planet. But real computers are actually getting to be a lot better. there’s been a revolution in our understanding of machine learning recently. And all depends on the ideas of this guy, the Reverend Thomas Bayes, who was statistician and mathematician in the 18th century. And essentially what Bayes did was to a mathematical way using probability theory to characterize, describe, the way that scientists find out the world. So what scientists do is they have a hypothesis they think might be likely to start with. They go out and it against the evidence. The evidence makes them change that hypothesis. Then test that new hypothesis and so on and so forth. what Bayes showed was a mathematical way that you could that. And that mathematics is at the core of the machine learning programs that we have now. And some 10 ago, I suggested that babies might be doing the same thing.
So you want to know what’s going on underneath those beautiful eyes, I think it actually looks something like this. This is Reverend Bayes’s notebook. So I think those are actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, now that seem like an even taller order to actually demonstrate. Because after all, 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 that lights up and plays music when you put some things it and not others. And using this very simple machine, my lab and others have done dozens studies showing just how good babies are at learning 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 block on top of the detector. But actually, this detector in a bit of a strange way. Because if you wave a block over the top the detector, something you wouldn’t ever think of to begin with, the detector will actually activate two 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. It looks as if the waving is a effective strategy than the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just them to make it go. And sure enough, the four year-olds the evidence to wave the object on top of the detector.
Now there are things 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 these quite complicated calculations will give them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, get to a hypothesis about the world, that seems unlikely to begin with. And in studies we’ve just been 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 same task. So these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, and we wanted see if children are doing experiments. When children do experiments we call “getting into everything” or else “playing.”
And there’s been a bunch interesting studies recently that have shown this playing around is really a kind of research program. Here’s one from Cristine Legare’s lab. What did was use our Blicket Detectors. And what she did was show children that yellow ones made it and red ones didn’t, and then she showed them an anomaly. And what you’ll is that this little boy will go through five hypotheses in space of two minutes.
(Video) Boy: How about this? Same as the other side.
Alison Gopnik: Okay, his first hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every scientist will recognize that 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 do this, to try putting it out onto the other location. Not working either.
Boy: Oh, because the goes only to here, not here. Oh, the bottom this box has electricity in here, but this doesn’t electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So when put four. So you put four on this one make it light up and two on this one to make light up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, but what Cristine is this is actually quite typical. If you look at the children play, when you ask them to explain something, they really do is do a series of experiments. This actually pretty 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 conscious if they conscious at all. And I think just the opposite is true. I babies and children are actually more conscious than we as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind of a spotlight. So what happens for adults is we that something’s relevant or important, we should pay attention to it. Our consciousness that thing that we’re attending to becomes extremely bright and vivid, and everything else of goes dark. And we even know something about way the brain does this.
So what happens when we pay attention 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 our brains. we have a very focused, purpose-driven kind of attention. we look at babies and young children, we see something different. I think babies and young children seem to more of a lantern of consciousness than a spotlight of consciousness. babies and young children are very bad at narrowing down just one thing. But they’re very good at taking in lots information from lots of different sources at once. And if actually look in their brains, you see that they’re flooded with neurotransmitters that are really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say babies and young children are bad at paying attention, what really mean is that they’re bad at not paying attention. So they’re at getting rid of all the interesting things that could tell them and just looking at the thing that’s important. That’s the kind of attention, kind of consciousness, that we might expect from those butterflies who are to learn.
Well if we want to think about a way of a taste of that kind of baby consciousness as adults, I think best thing is think about cases where we’re put in a new situation that we’ve never been in — when we fall in love with someone new, or when we’re in a new city for first time. And what happens then is not that our contracts, it expands, so that those three days in Paris seem to more full of consciousness and experience than all the of being a walking, talking, faculty meeting-attending zombie back home. And by the way, 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 being in love in Paris for the first time 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 too much about how wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the 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 be like butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults to start thinking more children.
(Applause)