What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would have said this baby was irrational, illogical, egocentric — that he couldn’t take the perspective of another or understand cause and effect. In the last 20 years, developmental science has completely overturned that picture. So in 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 that baby could be thinking about, that could be going in his mind, is trying to figure out what’s on in the mind of that other baby. After all, of the things that’s hardest for all of us to is to figure out what other people are thinking and feeling. And maybe hardest thing of all is to figure out that what other people think feel isn’t actually exactly like what we think and feel. Anyone who’s followed politics can testify how hard that is for some people to get. We wanted to if babies and young children could understand this really profound thing other people. Now the question is: How could we ask them? Babies, after all, can’t talk, and you ask a three year-old to tell you what thinks, what you’ll get is a beautiful stream of monologue about ponies and birthdays and things like that. 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 the babies two bowls of food: one bowl of raw and one bowl of delicious goldfish crackers. Now all of the babies, in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take a little taste food from each bowl. And she would act as if she liked it or she didn’t. half the time, she acted as if she liked the crackers didn’t like the broccoli — just like a baby and any other sane person. But half the time, she would do is take a little bit of the and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would a little bit of the crackers, and she’d go, “Eww, yuck, crackers. tasted the crackers. Eww, yuck.” So she’d act as if she wanted was just the opposite of 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 is: What would the baby give her, what they liked what she liked? And the remarkable thing was that 18 month-old babies, just barely and talking, would give her the crackers if she liked the crackers, but would give her the broccoli if she liked the broccoli. the other hand, 15 month-olds would stare at her for a long time she acted as if she liked the broccoli, like couldn’t figure this out. But then after they stared for a long time, they would give her the crackers, what they thought everybody must like. So there two really remarkable things about this. The first one is that these 18 month-old babies have already discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they felt that they should actually do things help other people get what they wanted.
Even more remarkably though, the that 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 they 15 months old. So children both know more and learn more than we ever have thought. And 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 learn so much? 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 many ways, they’re worse useless, because we have to put so much time energy into just keeping 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 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 like kangaroos and wombats, it turns out that there’s a relationship how long a childhood a species has and how big brains are compared to their bodies and how smart flexible they are.
And sort of the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows and corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as as chimpanzees in some respects. And this is a on the cover of science who’s learned how to use a tool get food. On the other hand, we have our friend the domestic chicken. And chickens and ducks and and turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much 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 really long time in the of a bird. Whereas the chickens are actually mature a couple of months. So childhood is the reason why the end up on the cover of Science and the chickens end in the soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what of explanation could we have for this? Well some animals, like chicken, seem to be beautifully suited to doing just one thing very well. So they seem to be suited to pecking grain in one environment. Other creatures, like crows, aren’t very good at doing anything in particular, but they’re extremely good at 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 bodies by far than any other animal. We’re smarter, we’re more flexible, we learn more, we survive in more different environments, we to cover the world and even go to outer space. our babies and children are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that learning strategy, is an powerful, great strategy for getting on in the world, but it has big disadvantage. And that one big disadvantage is that, until you actually do all that learning, you’re to be helpless. So you don’t want to have the mastodon charging at and be saying to yourself, “A slingshot or maybe a might work. Which would actually be better?” You want know all that before the mastodons actually show up. And the way the evolutions seems to have 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. we have to do is learn. And then as adults, we can take all things that we learned when we were babies and children and actually put them to to do things out there in the world.
So one way of thinking about is that babies and young children are like the research and development division the human species. So they’re the protected blue sky guys just have to go out and learn and have ideas, and we’re production and marketing. We have to all those ideas that we learned when we were children actually put them to use. Another way of thinking about it is instead of thinking babies and children as being like defective grownups, we should think about as being a different developmental stage of the same species — kind of caterpillars and butterflies — except that they’re actually the brilliant butterflies who are flitting around the garden exploring, and we’re the caterpillars who are inching along narrow, grownup, adult path.
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If this is true, if these are designed to learn — and this evolutionary story would say children for learning, that’s what they’re for — we might expect that they would have really learning mechanisms. And in fact, the baby’s brain seems to be the most powerful learning computer 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 it all depends on the ideas this guy, the Reverend Thomas Bayes, who was a statistician and mathematician in the 18th century. And essentially Bayes did was to provide a mathematical way using probability theory to characterize, describe, the way that scientists out about the world. So what scientists do is they a hypothesis that they think might be likely to 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 so forth. what Bayes showed was a mathematical way that you could do that. And mathematics is at the core of the best machine learning programs that we now. And some 10 years ago, I suggested that babies might doing the same thing.
So if you want to what’s going on underneath those beautiful brown eyes, I think it looks something like this. This is Reverend Bayes’s notebook. So think those babies are actually making complicated calculations with conditional probabilities that they’re revising to figure out the world works. All right, now that might seem 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 used a machine that we called the Blicket Detector. This is a box that up and plays music when you put some things on it and not others. And using this very machine, my lab and others have done dozens of studies showing just how good are at learning about the world. Let me mention just one that we did with Tumar Kushner, student. If I showed you this detector, you would be likely think to begin with that the way to make the detector go would be to a block on top of the detector. But actually, this detector works in bit of a strange way. Because if you wave block over the top of the detector, something you 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 the block the detector, it will only activate two out of times. So the unlikely hypothesis actually has stronger evidence. It as if the waving is a more effective strategy the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just asked them to it go. And sure enough, the four year-olds used evidence to wave the object on top of the detector.
Now there two things that are really interesting about this. The one is, again, remember, these are four year-olds. They’re just learning how to count. But unconsciously, they’re these 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 to a about the world, that seems very unlikely to begin with. And in studies we’ve just been doing my lab, similar studies, we’ve show that four year-olds are actually better at finding out 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 experiments. When children do experiments we call it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown this playing around is really a kind of experimental 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 five hypotheses in the space of two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has just falsified.
(Laughter)
Boy: This one lighted up, and this nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this 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 needs to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his idea. He told the experimenter to do this, to try putting it out onto the location. Not working either.
Boy: Oh, because the light only to here, not here. Oh, the bottom of this box electricity 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 this to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — that is a particularly and articulate little boy, but what Cristine discovered is this is actually typical. If you look at the way children play, when you ask them to something, what they really do is do a series of experiments. This is actually typical of four year-olds.
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Well, what’s it to be this kind of creature? What’s it like be one of these brilliant butterflies who can test hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have said that and 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 conscious we are as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind like a spotlight. So what happens for adults is we decide that something’s relevant or important, should pay attention 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 even know something about the way the brain this.
So what happens when we pay attention is that prefrontal cortex, the sort of executive part of our brains, sends a signal makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in the rest of our brains. So 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 a spotlight of consciousness. So babies and young children are bad at narrowing down to just one thing. But they’re good at taking in lots of information from lots different sources at once. And if you actually look in brains, you see that they’re flooded with these neurotransmitters that are really at inducing learning and plasticity, and the inhibitory parts haven’t come yet. So when we say that babies and young are bad at paying attention, what we really mean is that they’re at not paying attention. So they’re bad at getting rid all the interesting things that could tell them something just looking at the thing that’s important. That’s the of attention, the kind of consciousness, that we might expect those butterflies who are designed to learn.
Well if we want to think about a way of a taste of that kind of baby consciousness as adults, I the best thing is think about cases where we’re put in new situation that we’ve never been in before — when we fall in love with someone new, or we’re in a new city for the first time. And what happens then is not that consciousness contracts, it expands, so that those three days in seem to be more full of consciousness and experience than all the of being a walking, talking, faculty meeting-attending zombie back home. by the way, that coffee, that wonderful coffee you’ve drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it to 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 the morning.
(Laughter)
Now it’s good be a grownup. I don’t want to say too much about wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street by ourselves. And it sense that we put a lot of effort into making babies think like adults do. But if what want is to be like those butterflies, to have open-mindedness, learning, imagination, creativity, innovation, maybe at least some of the time should be getting the adults to start thinking more children.
(Applause)