What is going in this baby’s mind? If you’d asked people this 30 ago, most people, including psychologists, would have said that this was irrational, illogical, egocentric — that he couldn’t take the perspective another person or understand cause and effect. In the last 20 years, developmental science 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 to figure out what’s going on in the mind of that other baby. After all, one of things that’s hardest for all of us to do is 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 and feel. who’s followed politics can testify to how hard that is for people to 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, after all, can’t talk, and if 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 do we ask them the question?
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Well it turns out that secret was broccoli. What we did — Betty Rapacholi, who one of my students, and I — was actually give the babies two bowls of food: one bowl of raw and one bowl of delicious goldfish crackers. Now all of the babies, even Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But what Betty did was to take a little taste of food from bowl. And she would act as if she liked it or didn’t. So half the time, she acted as if liked the crackers and didn’t like the broccoli — like a baby and any other sane person. But the time, what she would do is take a little bit of the and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a little bit of crackers, and 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 18 month-old babies. And then she would simply put her out and say, “Can you give me some?”
So the question is: What the 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 stare at her for a long time if she as if she liked the broccoli, like they couldn’t figure this out. But after they stared for a long time, they would just give her crackers, what they thought everybody must like. So there are two really remarkable things this. The first one is that these little 18 month-old babies have discovered this really profound fact about human nature, that we don’t always want the thing. And what’s more, they felt that they should actually things to help other people get what they wanted.
Even more though, the fact that 15 month-olds didn’t do this suggests that these 18 month-olds learned this deep, profound fact about human nature in the three months from 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 and hundreds studies over the last 20 years that’s actually 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 learn so 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 we have to put much time and energy into just keeping them alive. But if turn to evolution for an answer to this puzzle of we spend so much time taking care of useless babies, it out that there’s actually an answer. If we look many, many different species of animals, not just us primates, but also including mammals, birds, even marsupials like kangaroos and wombats, it out that there’s a relationship between how long a childhood a species has and how big their 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 corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart as chimpanzees in 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 our friend domestic chicken. And chickens and ducks and geese and turkeys are as dumb as dumps. So they’re very, very good pecking for grain, and they’re not much good at doing else. Well it turns out that the babies, the New Caledonian babies, are 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 the of a bird. Whereas the chickens are actually mature within a couple of months. So is the reason why the crows end up on the cover Science and the chickens end up in the soup pot.
There’s something that long childhood that seems to be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, like the chicken, seem to be suited to doing just one thing very well. So they to 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 good at learning about laws of different environments.
And of course, we human beings are out on the end of the distribution like the crows. We bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to cover the and even go to outer space. And our babies children are dependent on us for much longer than the babies of other species. My son is 23. (Laughter) And at least until they’re 23, we’re still those worms into those little open mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, is an extremely powerful, great for getting on in the world, but it has 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 the mastodon charging at you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” want to know all that before the mastodons actually show up. And the way the seems to have solved that problem is with a kind of division of labor. So 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 those 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 about it is that babies and young children are like the research and development division the human species. So they’re the protected blue sky guys who just have to go out learn and have good ideas, and we’re production and marketing. We have take all those ideas that we learned when we children and actually put them to use. Another way of about it is instead of thinking of babies and children as being like defective grownups, we should about them 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 are along our narrow, grownup, adult path.
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If this is true, if these babies are designed to — and this evolutionary story would say children are learning, that’s what they’re for — we might expect that would have really powerful learning mechanisms. And in fact, baby’s brain seems to be the most powerful learning computer on the planet. But real computers are getting to be a lot better. And there’s been revolution in our understanding of machine learning recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician and mathematician in 18th century. And essentially what Bayes did was to provide a mathematical way using theory to characterize, describe, the way that scientists find out about the world. So what scientists do they have 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 they test new hypothesis and so on and so forth. And what Bayes showed was mathematical way that you could do that. And that mathematics is at the core of the best learning programs that we have now. And some 10 years ago, I suggested that babies be doing the same thing.
So if you want know what’s going on underneath those beautiful brown eyes, I think it actually something like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional that they’re revising to figure out how the world works. All right, now that might seem like even taller order to actually demonstrate. Because after all, if you ask even about statistics, they look extremely stupid. How could it that children are doing statistics?
So to test this we used a that we have called the Blicket Detector. This is a box that lights up and plays music when put some things on it and not others. And using very simple machine, my lab and others have done dozens of showing just how good babies are at learning about the world. Let me just one that we did with Tumar Kushner, my student. If I showed this detector, you would be likely to think to begin with that way to make the detector go would be to put a block on top of the detector. actually, this detector works in a 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, the will actually activate two out of three times. Whereas, if you do the likely thing, put block on the detector, it will only activate two out of six times. So the unlikely hypothesis has stronger evidence. It looks as if the waving is a effective strategy than the other strategy. So we did just this; gave four year-olds this pattern of evidence, and we just them to make it go. And sure enough, the year-olds used the evidence to wave the object on of the detector.
Now there are two things that are 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 complicated 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, to a hypothesis about the world, that seems very to begin with. And in studies we’ve just been in my lab, similar studies, we’ve show that four year-olds are better at finding out an unlikely hypothesis than adults are when we give them exactly the same task. in these circumstances, the children are using statistics to find out about the world, but all, scientists also do experiments, and we wanted to see children are doing experiments. When children do experiments we it “getting into everything” or else “playing.”
And there’s been a bunch interesting studies recently that have shown this playing around is 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 red ones didn’t, and she showed them an anomaly. And what you’ll see is that this little boy will through five hypotheses in the space of two minutes.
(Video) Boy: How 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 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 like this, and this needs to be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: this is his next idea. He told the experimenter to do this, try putting it out onto the other location. Not working either.
Boy: Oh, because the light goes only here, not here. Oh, the bottom of this box electricity in here, but this doesn’t have electricity.
AG: Okay, that’s fourth hypothesis.
Boy: It’s lighting up. So when you put four. So put four on this one to make it light and two on this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, but what discovered is this is actually quite typical. If you look at the way play, when you ask them to explain something, what they do is do a series of experiments. This is actually pretty typical of year-olds.
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Well, what’s it like to be kind of creature? What’s it like to be one of these brilliant butterflies who can test hypotheses in two minutes? Well, if you go back to those psychologists and philosophers, a lot of them said that babies and young children were barely conscious if they were conscious all. And 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. And adults’ and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant or important, we pay attention to it. Our consciousness of that thing that we’re attending becomes extremely bright and vivid, and everything else sort of goes dark. we even know something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, sort 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 down activity in all the rest of our brains. So we have a focused, purpose-driven kind of attention. If we look at and young children, we see something very different. I think babies and young children to have more of a lantern of consciousness than a of consciousness. So babies and young children are very at narrowing down to just one thing. But they’re very good taking in lots of information from lots of different sources at once. if you actually look in their brains, you see that they’re flooded with these neurotransmitters that really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say that babies young children are bad at paying attention, what we really mean is that they’re bad not paying attention. So they’re bad at getting rid all the interesting things that could tell them something and just at the thing that’s important. That’s the kind of attention, the kind of consciousness, that might expect from those butterflies who are designed to learn.
Well if 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 situation that we’ve never been in before — when we fall in 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, that those three days in Paris seem to be more full of consciousness and than all the months of being a walking, talking, faculty meeting-attending back home. And by the way, that coffee, that wonderful coffee you’ve drinking downstairs, actually mimics the effect of those baby neurotransmitters. what’s it like to be a baby? It’s like in love in Paris for the first time after you’ve had three double-espressos. (Laughter) That’s a fantastic way be, but it does tend to leave you waking up crying at o’clock in the morning.
(Laughter)
Now it’s good to be grownup. I don’t want to say too much about how babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street ourselves. And it makes sense that we put a lot of effort into making babies like adults do. But if what we want is to be those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe least some of the time we should be getting the adults to start thinking more children.
(Applause)