What is going on in this baby’s mind? If you’d people 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 understand cause and effect. In the last 20 years, developmental science has completely that picture. So in some ways, we think that this baby’s thinking like the thinking of the most brilliant scientists.
Let give you just one example of this. One thing that this baby could be thinking about, that be going on in his mind, is trying to figure out what’s going in the mind of that other baby. After all, one of things that’s hardest for all of us to do is to out what other people are thinking and feeling. And maybe the thing of all is to figure out that what other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can testify to how hard that is some people to get. We wanted to know if babies and young children could understand this profound thing about other people. Now the question is: How 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 get is a beautiful of consciousness monologue about ponies and birthdays and things like that. So how we actually ask them the question?
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Well it turns out that the secret was broccoli. we did — Betty Rapacholi, who was one of my students, I — was actually to give the babies two bowls of food: one of raw broccoli 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 little taste of food from each bowl. And she would act as if liked it or she didn’t. So half the time, she acted as if she liked crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what she do is take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” then she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” she’d act 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 give me some?”
So the question is: What would the baby 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 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 time, they would just give her the crackers, what they thought everybody must like. So there are two remarkable things about this. The first one is that little 18 month-old babies have already discovered this really profound about human nature, that we don’t always want the same thing. what’s more, they felt that they should actually do to help other people get what they wanted.
Even remarkably though, the fact that 15 month-olds didn’t do suggests that these 18 month-olds had learned this deep, profound fact about human nature in the three months when they were 15 months old. So children both know more and learn more than we would have thought. And this is just one of hundreds 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 them to learn so much such a short time? I mean, after all, if you look at babies superficially, they seem pretty useless. actually in many ways, they’re worse than useless, because we have put so much time and energy into just keeping them alive. But if we turn to evolution for answer to 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 other mammals, birds, even marsupials like kangaroos and wombats, turns out that there’s a relationship between 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 up there. On one side a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as smart as chimpanzees in some respects. And is a bird on the cover of science who’s how to use a tool to get food. On the 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, very at pecking for grain, and they’re not much good doing anything else. Well it turns out that the babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little open mouths for as long two years, which is a really long time in life of a bird. Whereas the chickens are actually mature within couple of months. So childhood is the reason why crows end up on the cover of Science and the chickens end up in the soup pot.
There’s about that long childhood that seems to be connected to knowledge and learning. Well kind of explanation could we have for this? Well some animals, like the chicken, seem be beautifully suited to doing just one thing very well. So they seem be beautifully suited to pecking grain in one environment. Other creatures, like crows, aren’t very good at doing anything in particular, but they’re good at learning about laws of different environments.
And course, we human beings are way out on the end the distribution like the crows. We have bigger brains relative to our bodies by far 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 the 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 we see this correlation? Well an idea that that strategy, that learning strategy, is an extremely powerful, great strategy for getting in the world, but it has one big disadvantage. And that big disadvantage is that, until you actually do all that learning, you’re going to helpless. So you don’t want to have the mastodon charging at you and be saying yourself, “A slingshot or maybe a spear might work. Which would actually better?” You want to know all that before the mastodons actually show up. And the way evolutions seems to have solved that problem is with a kind of of labor. So the idea is that we have this early 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 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 young are like the research and development division of the human species. So they’re protected blue sky guys who just have to go and learn and have good ideas, and we’re production and marketing. We have to take 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 about them as being a different developmental stage of the species — kind of like caterpillars and butterflies — except that they’re actually the butterflies 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 — might expect that they would have really powerful learning mechanisms. in fact, the baby’s brain seems to be the most powerful learning computer the planet. But real computers are actually getting to be lot better. And there’s been a revolution in our of machine learning recently. And it all depends on ideas of this guy, the Reverend Thomas Bayes, who was statistician and mathematician in the 18th century. And essentially what Bayes was to provide a mathematical way using probability theory to characterize, describe, way that scientists find out about the world. So scientists do is they have a hypothesis that they think might be likely start with. They go out and test it against the evidence. The makes them 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. And that mathematics at the core of the best machine learning programs we have now. And some 10 years ago, I suggested that babies might be doing same thing.
So if you want to know what’s going on underneath those brown eyes, I think it actually looks something like this. This Reverend Bayes’s notebook. So I think those babies are actually making complicated calculations with probabilities that they’re revising to figure out how the world works. All right, that might seem like an even taller order to actually demonstrate. after all, if you ask even grownups about statistics, they extremely stupid. How could it be that children are doing statistics?
So to this we used a machine that we have called the Blicket Detector. This a box that lights up and plays music when put some things on it and not others. And using this very simple machine, my lab and others done dozens of studies showing just how good babies are at learning about the world. me mention just one that we did with Tumar Kushner, my student. If I showed you this detector, you be likely to think to begin with that the to make the detector go would be to put a on top of the detector. But actually, this detector works a bit of a strange way. Because if you wave a block over top of the detector, something you wouldn’t ever think to begin with, the detector will actually activate two out of three times. Whereas, if you do likely thing, put the block on the detector, it will only two out of six times. So the unlikely hypothesis has stronger evidence. It looks as if the waving is a more strategy than the other strategy. So we did just this; we gave four year-olds this pattern of evidence, and just asked them to make it go. And sure enough, the year-olds used the evidence to wave the object on top the detector.
Now there are two things that are really interesting about this. first one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these complicated 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. in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better at finding out unlikely hypothesis than adults are when we give them exactly the same task. So in these circumstances, children are using statistics to find out about the world, but after all, also do experiments, and we wanted to see if children are doing experiments. When do experiments we call it “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 made it go and red ones didn’t, and then showed them an anomaly. And what you’ll see is that little boy will go through five hypotheses in the space of minutes.
(Video) Boy: How about this? Same as the other side.
Alison Gopnik: Okay, so his hypothesis has just been falsified.
(Laughter)
Boy: This one up, and 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 expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this his next idea. He told the experimenter to do this, to try putting it out onto other location. Not working either.
Boy: Oh, because the light goes only to here, not here. Oh, the of this box has 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. you put four on this one to make it light up two 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 way children play, when you ask them to explain something, what they 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 like be one of these brilliant butterflies who can test five hypotheses in two minutes? Well, if you go to those psychologists and philosophers, a lot of them have said that babies young children were barely conscious if they were conscious at all. I think just the opposite is true. I think and children are actually more conscious than we are adults. Now here’s what we know about how adult consciousness works. adults’ attention and consciousness look kind of like a spotlight. what happens for adults is we decide that something’s or important, we should pay attention to it. Our of that thing that we’re attending to becomes extremely and vivid, and everything else sort of goes dark. 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, a signal that makes a little part of our much more flexible, more plastic, better at learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven kind attention. If we look at babies and young children, see something very different. I think babies and young children to have more of a lantern of consciousness than a spotlight of consciousness. So babies young children are very bad at narrowing down to just one thing. But they’re good at taking in lots of information from lots of different sources at once. if you actually look in their brains, you see they’re flooded with these neurotransmitters that are really good at inducing learning 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 mean that they’re bad at not paying attention. So they’re bad 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, the kind consciousness, that we might expect from those butterflies who are designed learn.
Well if we want to think about a way of getting a of that kind of baby consciousness as adults, I think the thing is think 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 is not that our 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 wonderful you’ve been drinking downstairs, actually mimics the effect of those neurotransmitters. So what’s it like to be a baby? It’s like being in in Paris for the first time after you’ve had 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 about how wonderful babies are. It’s good to be a grownup. We can do things like tie shoelaces and cross the street by ourselves. And it makes sense we put a lot of effort into making babies like adults do. But if what we want is to like those 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)