What is going in this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, would said that 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 has completely overturned that picture. So in some ways, we that this baby’s thinking is like the thinking of most brilliant scientists.
Let me give you just one example of this. One thing that this baby could thinking about, that could be going on in his mind, is trying to figure out what’s going on the mind of 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 is to figure out that what other people think and feel isn’t exactly like what we think and feel. Anyone who’s followed can testify to how hard that is for some to get. We wanted to know if babies and young children understand this really profound thing about other people. Now the question is: How could ask them? Babies, after all, can’t talk, and if 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 do we actually ask them the question?
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it turns out that the secret was broccoli. What we — Betty Rapacholi, who was one of my students, I — was actually to give the babies two of food: one bowl of raw broccoli and one bowl of delicious goldfish crackers. all of the babies, even in Berkley, like the and don’t like the raw broccoli. (Laughter) But then what Betty did was to take little taste of food from each bowl. And she would act as if she liked it she didn’t. So half the time, she acted as if she liked the and didn’t like the broccoli — just like a and any other sane person. But half the time, 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 of the crackers, and she’d go, “Eww, yuck, crackers. tasted the crackers. Eww, yuck.” So she’d act as what she wanted was just the opposite of what the babies wanted. did this with 15 and 18 month-old babies. And then she simply 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 was 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. On the other hand, 15 month-olds stare at her for a long time if she acted as she liked the broccoli, like they couldn’t figure this out. But then after stared for a long time, they would just give her the crackers, what they thought everybody like. So there are two really remarkable things about this. The first is 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 they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds learned this deep, profound fact about human nature in the three from when 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: do children learn so much? And how is it possible for to learn so much in such a short time? I mean, all, if 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 if turn to evolution for an answer to this puzzle of why we spend so much taking care of useless babies, it turns out that there’s actually an answer. we look across many, many different species of animals, not just us primates, also including 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 their brains are compared to their bodies and how smart and flexible are.
And sort 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 so forth, are incredibly smart birds. They’re as smart as in some respects. And this is a bird on the cover of who’s learned how to use a tool to get food. On other hand, we have our friend the domestic chicken. And chickens ducks and geese and turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much good at doing anything else. Well it turns out the babies, the New Caledonian crow babies, are fledglings. They depend on their to drop worms in their little open mouths for long as two years, which is a really long in the life 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 kind of 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 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 are way out on the end of the distribution like the crows. We have brains relative to our bodies by far than any other animal. We’re smarter, we’re flexible, we can learn more, we survive in more different environments, we migrated cover the world and even go to outer space. And our babies and children are dependent us for much longer than the babies of any other species. My son 23. (Laughter) And at least until they’re 23, we’re popping those worms 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, great strategy getting on in the world, but it has one big disadvantage. And one big disadvantage is that, until you actually do all learning, you’re going to be helpless. So you don’t want to have 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 mastodons show up. And the way the evolutions seems to have solved that is with a kind of division of labor. So the idea that we have this early period when we’re completely protected. We don’t have to do anything. All we to do is learn. And then as adults, we can take all things that we learned when we were babies and and actually put them to work to do things out there the world.
So one way of thinking about it is that babies and young children like the research and development division of the human species. So they’re the blue sky guys who just have to go out and and have good ideas, and we’re production and marketing. have to take all those ideas that we learned we were children and actually put them to use. Another of thinking about it is instead of thinking of and children as being like defective grownups, we should think about them as being a different developmental stage the same species — kind of like caterpillars and — except that they’re actually the brilliant butterflies who are flitting around the garden exploring, and we’re the caterpillars who are inching along our narrow, grownup, adult path.
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If this true, if these babies are designed to learn — and this evolutionary story 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 computer the planet. But real computers are actually getting 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, the Thomas Bayes, who was a statistician and mathematician in 18th century. And essentially what Bayes did was to provide a mathematical using probability theory to characterize, describe, the way that scientists find out about the world. So scientists do is they have a hypothesis that they think might be likely to start with. go out and test it against the evidence. The makes them change that hypothesis. Then they test that new hypothesis and so on so forth. And what Bayes showed was a mathematical way you could do that. And that mathematics is at the core of the machine learning 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 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. 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 on it and not others. And using this very simple machine, my lab and have done dozens of studies showing just how good babies are at 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 to think begin with that the way to make the detector go would be to put block on top of the detector. But actually, this detector works in bit of a strange way. Because if you wave a block over top of the detector, something you wouldn’t ever think of to begin with, detector will actually activate two out of three times. Whereas, if you do the thing, put the block on the detector, it will only activate two out of times. So the unlikely hypothesis actually has stronger evidence. looks as if the waving is a more effective strategy the other strategy. So we did just this; we gave four year-olds this of evidence, and we just asked them to make it go. And enough, the four year-olds used the evidence to wave the on top of the detector.
Now there are two that are really interesting about this. The first one is, again, remember, these four year-olds. They’re just learning how to count. But unconsciously, they’re doing these quite calculations that will give them a conditional probability measure. And the interesting thing is that they’re using that evidence to get to an idea, get to hypothesis about the world, that seems very unlikely to with. And in studies we’ve just been doing in lab, similar studies, we’ve show that four year-olds are actually at finding out an unlikely hypothesis than adults are we give them exactly the same task. So in circumstances, the children are using statistics to find out about the world, but after all, scientists also experiments, and we wanted to see if children are doing experiments. When children do we call it “getting into everything” or else “playing.”
And there’s been bunch of interesting studies recently that have shown this playing around is really a kind experimental research program. Here’s one from Cristine Legare’s lab. What Cristine was use our Blicket Detectors. And what she did was children that yellow ones made it go and red ones didn’t, and then she showed them 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 the other side.
Alison Gopnik: Okay, so first hypothesis 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) don’t know.
AG: Every scientist will recognize that expression despair.
(Laughter)
Boy: Oh, it’s because this needs to be this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his idea. He told the experimenter to do this, to try it out onto the other location. Not working either.
Boy: Oh, because light goes only 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 put four. So you put four on this one to it light up and two on this one to make light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and articulate little boy, what Cristine discovered is this is actually quite typical. you look at the way children play, when you ask them to explain something, what really do is do a series of experiments. This is actually pretty typical four year-olds.
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Well, what’s it like to be this kind of creature? What’s it to be one of these brilliant butterflies who can five hypotheses in two minutes? Well, if you go to those psychologists and philosophers, a lot of them have that babies and young children were barely conscious if they were conscious all. And I think just the opposite is true. I think babies and are actually more conscious than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens for is we decide that something’s relevant or important, we should pay attention to it. consciousness of that thing that we’re attending to becomes extremely and vivid, and everything else sort of goes dark. And we know something about the way the brain does this.
So happens when we pay attention is that the prefrontal cortex, the of executive part of our brains, sends a signal that makes a little part our brain much 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. If look at babies and young children, we see something different. I think babies and young children seem to have 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 of from lots of different sources at once. And if you look in their brains, you see that they’re flooded with these neurotransmitters that are really good inducing learning and plasticity, and the inhibitory parts haven’t on yet. So when we say that babies and young children bad at paying attention, what we really mean is that they’re bad not paying attention. So they’re bad at getting rid of all the interesting things that tell them something and just looking at the thing that’s important. That’s the of attention, the kind of consciousness, that we might from those butterflies who are designed to learn.
Well if we to think about a way of getting a taste of kind of baby consciousness as adults, I think the best thing is about cases where we’re put in a new situation that we’ve never in before — when we fall in love with someone new, or when we’re in new city for the first time. And what happens then not that our consciousness contracts, it expands, so that those three days in seem to be more full of consciousness and experience than the months of being a walking, talking, faculty meeting-attending back home. And by the way, that coffee, that coffee you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it like 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 does 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 how wonderful babies are. It’s good be a 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 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)