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 couldn’t take the perspective of another person or understand cause and effect. the last 20 years, developmental science has completely overturned that picture. So in some ways, we think that baby’s thinking is like the thinking of the most brilliant scientists.
Let me give just one example of this. One thing that this baby could be about, that could 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 the 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 to figure out 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 for some people get. We wanted to know if babies and young could understand this really profound thing about other people. the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old to tell what he thinks, what you’ll get is a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how we actually ask them the question?
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Well it out that the secret was broccoli. What we did — Rapacholi, who was one of my students, and I — was to give the babies two bowls of food: one bowl of raw and one bowl of delicious goldfish crackers. Now all the babies, even in Berkley, like the crackers and don’t like the raw broccoli. (Laughter) then what Betty did was to take a little taste of food from each bowl. And 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 sane person. But half the time, what she would do is take a little of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then would 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 just the opposite of what the wanted. We did this with 15 and 18 month-old babies. then she would simply put her hand out and say, “Can you give me some?”
So question is: What would the baby give her, what they liked or what she liked? And remarkable thing was 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 at her for a long time if she acted as if she liked the broccoli, like couldn’t figure this out. But then after they stared a long time, they would just give her the crackers, they thought everybody must like. So there are two really remarkable things this. The first one is that these little 18 month-old babies already discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they that they should actually do things to help other people what they wanted.
Even more 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 in the three months from when they were 15 months old. So children both know more and more than we ever would have thought. And this is just one of hundreds and hundreds studies over the last 20 years that’s actually demonstrated it.
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question you might ask though is: Why do children learn so much? And how it possible for them to learn so much in such 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, we have to put so much time and energy into just keeping them alive. But if we to evolution for an answer to this puzzle of why we so much time taking care of useless babies, it turns out that there’s actually an answer. If we across many, many different species of animals, not just primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s relationship between how long a childhood a species has and how their brains are compared to their bodies and how smart and flexible they are.
And 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 to get food. the other hand, we have our friend the domestic chicken. And chickens and ducks and geese and 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, fledglings. They depend on their moms to drop worms in their little open for as long as 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 the end up on the cover of Science and the chickens up in the soup pot.
There’s something about that long that seems to be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, the chicken, seem to be beautifully suited to doing just one thing very well. So they seem be beautifully suited to pecking grain in one environment. Other creatures, the crows, aren’t very good at doing anything in particular, but they’re extremely good at learning about laws of environments.
And of course, we human beings are way out on the end the distribution like the crows. We have bigger brains relative to our bodies far than any other animal. We’re smarter, we’re more flexible, we learn more, we survive in more different environments, we migrated to cover the and even go to outer space. And our babies and are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at least they’re 23, we’re still popping those worms into those little mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, is extremely powerful, great strategy for getting on in the world, it has one big disadvantage. And that one big disadvantage is that, until actually do all that learning, you’re going to be helpless. So you don’t want to have the mastodon charging you and be saying to yourself, “A slingshot or maybe a spear work. Which would actually be better?” You want to know all that before the mastodons show up. And the way the evolutions seems to have solved that problem is a kind of division of labor. So the idea is that we have this early period when we’re 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 children actually put them to work to do things out there the world.
So one way of thinking about it is that and young children are like the research and development of the human species. So they’re the protected blue guys who just have to go out and learn and have good ideas, we’re production and marketing. We have to take all those that we learned when we were children and actually them to use. Another way of thinking about it is of thinking of babies and children as being like defective grownups, we should think about them as being different developmental stage of the same species — kind of like caterpillars butterflies — except that they’re actually the brilliant butterflies are flitting around the garden and exploring, and we’re the caterpillars are inching along our narrow, grownup, adult path.
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If this is true, these babies are designed to learn — and this evolutionary would say children are for learning, that’s what they’re — we might expect that they would have really learning mechanisms. And in fact, the baby’s brain seems to be the most learning computer on the planet. But real computers are getting to be a lot better. And there’s been a revolution in 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 the 18th century. essentially what Bayes did was to provide a mathematical way using probability theory characterize, describe, the way that scientists find out about the world. So what scientists do is they a hypothesis that they think might be likely to start with. They go and test 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 do that. And that mathematics is at the of the best machine learning programs that we have now. And 10 years ago, I suggested that babies might be doing the thing.
So if you want to know what’s going on those beautiful brown eyes, I think it actually looks like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional probabilities that they’re revising figure out how the world works. All right, now might seem like an even taller order to actually demonstrate. Because after all, you ask even grownups about statistics, they look extremely stupid. How could it that children are doing statistics?
So to test this we used a machine that we have the Blicket Detector. This is a box that lights up and plays music when put some things on it and not others. And using this very 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. I showed you this detector, you would be likely to think to begin with that way to make the detector go would be to a block on top of the detector. But actually, detector works in a bit of a strange way. Because you wave a block over the top of the detector, you wouldn’t ever think of to begin with, the will actually activate two out of three times. Whereas, you do the likely thing, put the block on detector, it will only activate two out of six times. So the unlikely actually has stronger evidence. It looks as if the is a more effective strategy than the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just asked them to make it go. sure enough, the four year-olds used the evidence to the object on top of 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 quite complicated calculations that will them a conditional probability measure. And the other interesting thing is that they’re that evidence to get to an idea, get to hypothesis about the world, that seems very unlikely to begin with. in studies we’ve just been doing in my lab, similar studies, we’ve that four year-olds are actually better at finding out an unlikely hypothesis than are when we give them exactly the same task. So these circumstances, the children are using statistics to find out about the world, but after all, scientists do 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 a bunch 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 ones didn’t, and then she showed them an anomaly. And what you’ll see that this 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 first 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 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 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 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 — that is a particularly adorable and articulate little boy, but what Cristine is this is actually quite typical. If you look at the way children play, you ask them to explain something, what they really do is do a series of experiments. This is pretty typical of four year-olds.
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Well, what’s 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 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 are as adults. Now here’s what we know how adult consciousness works. And adults’ attention and consciousness kind of like a spotlight. So what happens for adults is decide that something’s relevant or important, we should pay attention to it. consciousness of that thing that we’re attending to becomes extremely bright vivid, and everything else sort of goes dark. And we even something about the way the brain does this.
So happens when we pay attention is that the prefrontal cortex, the sort of executive of our brains, sends a signal that makes a little of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest our brains. So 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 have more a lantern of consciousness than a spotlight of consciousness. So babies and young children are bad at narrowing down to just one thing. But they’re very good at taking lots of information from lots of different sources at once. And you actually look in their brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say that babies and children are bad at paying attention, what we really is that they’re bad at not paying attention. So they’re at getting rid of all the interesting things that could them something and just looking at the thing that’s important. That’s the kind of attention, the of consciousness, that we might expect from those butterflies are designed to learn.
Well if we want to about a way of getting a taste of that of baby consciousness as adults, I think the best thing is think about cases where we’re in a new situation that we’ve never been in before — when fall in love with someone new, or when we’re in a new city for the time. And what happens then is not that our consciousness contracts, it expands, so that those three days Paris seem to be more full of consciousness and experience all the months 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 of those baby 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 three double-espressos. (Laughter) That’s fantastic way to be, but it does tend to you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t 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 into making babies think like adults do. But if what we want is be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be the adults to start thinking more like children.
(Applause)