What going on in this baby’s mind? If you’d asked people this 30 years ago, most people, psychologists, would have said 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 picture. So in some ways, we think that this baby’s is like the thinking of the most brilliant scientists.
Let give you just one example of this. One thing that this could be thinking about, that could be going on 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 feeling. And maybe the hardest thing of all is figure out that what other people think and feel isn’t actually exactly like what 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 young children could 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 and things like that. So how do we actually ask them question?
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Well it turns out that the was broccoli. What we did — Betty Rapacholi, who was one of my students, and — was actually to give the babies two bowls food: one bowl of raw broccoli and one bowl of delicious goldfish crackers. all of the babies, even in Berkley, like the crackers don’t like the raw broccoli. (Laughter) But then what Betty did was to take a little of food from each bowl. And she would act as if she liked or she didn’t. So half the time, she acted if she liked the crackers and didn’t like the — just like a baby and any other sane person. half the time, what she would do is take a little bit of broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And she would take 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 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 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 give her the if she liked the broccoli. On the other hand, 15 month-olds stare 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, what they thought everybody must like. So there two really remarkable things about this. The first one is that these little 18 month-old have already 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 remarkably though, fact that 15 month-olds didn’t do this suggests that these 18 month-olds had learned this deep, profound about human nature in the three months from when they were 15 months old. So both know more and learn more than we ever would thought. And this is just one of hundreds and hundreds of 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 much in such a time? I mean, after all, if you look at babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to put much time and energy into just keeping them alive. But if we turn to evolution for an answer this puzzle of why we spend so much time taking of useless babies, it turns out that there’s actually an answer. we look across many, many different species of animals, just us primates, but also including other mammals, birds, even marsupials like and wombats, it turns out that there’s a relationship between how long a a species has and how big their brains are compared to their and how smart and flexible they are.
And sort of the posterbirds for this idea are the up there. On one side is a New Caledonian crow. And crows other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re smart as chimpanzees in some respects. And this is a bird the cover of science who’s learned how to use tool to get food. On the other hand, we have our friend the domestic chicken. And chickens and and geese and turkeys are basically as dumb as dumps. they’re very, very good at pecking for grain, and they’re much good at doing anything else. Well it turns out that the babies, the Caledonian crow babies, are fledglings. They depend on their to drop worms in their little open mouths for as long two years, which is a really long time in the life a bird. Whereas the chickens are actually mature within a of months. So childhood is the reason why the crows end up on the cover 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 chicken, seem to be beautifully suited to doing just one very well. So they seem to be beautifully suited to pecking grain in environment. Other creatures, like the crows, aren’t very good at doing anything particular, but they’re extremely good at learning about laws of different environments.
And course, we human beings are way out on the end of the like the crows. We have bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can learn more, we survive more different environments, we migrated to cover the world even go to outer space. And our babies and children are dependent on us for much longer than babies of any other species. My son is 23. (Laughter) at least until they’re 23, we’re still popping those worms into those little open mouths.
All right, would we see this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in the world, but it one big disadvantage. And that one big disadvantage is that, until you do all that learning, you’re going to be helpless. So you don’t to have the 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 problem 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 to do anything. All we have to do is learn. And then as adults, can take all those things that we learned when we babies and children and actually put them to work to do things out there the world.
So one way of thinking about it that babies and young children are like the research development division of the human species. So they’re the protected blue guys who just have to go out and learn have good ideas, and we’re production and marketing. We have to take all those ideas that we learned we were children and actually put them to use. Another way of about it is instead of thinking of babies and as being like defective grownups, we should think about them as being a different developmental of the same species — kind of like caterpillars and butterflies — except they’re actually the brilliant butterflies who are flitting around the garden and exploring, and we’re the who are inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to learn — and this evolutionary would say children are for learning, that’s what they’re for — we might expect that they would have powerful learning mechanisms. And in fact, the baby’s brain seems to be the powerful learning computer on the planet. But real computers are getting to be a lot better. And there’s been a in our understanding of machine learning recently. And it all on the ideas of this guy, the Reverend Thomas Bayes, was a statistician and mathematician in the 18th century. And essentially what Bayes did to provide a mathematical way using probability theory to characterize, describe, the way that scientists find out about world. So what scientists do is they have a 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 hypothesis and so on and so forth. And what Bayes showed was a way that you could do that. And that mathematics is at the core the best machine learning programs that we have now. And some 10 years ago, I suggested that babies be doing the same thing.
So if you want to know what’s on underneath those beautiful brown eyes, I think it looks something like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional probabilities that they’re revising to figure out how world works. All right, now that might seem like an taller order to actually demonstrate. Because after all, if you even grownups about statistics, they look extremely stupid. How could be that children are doing statistics?
So to test we used a machine that we have called the Detector. This is a box that lights up and plays when you put some things on it and not others. And this very simple machine, my lab and others have dozens of studies showing just how good babies are at learning about the world. Let me mention just that we did with Tumar Kushner, my student. If I showed this detector, you would be likely to think to begin with that the way to make detector go would be to put a block on top the detector. But actually, this detector works in a bit of 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 of three times. Whereas, if you do the likely thing, the block on the detector, it will only activate two out of six times. So the hypothesis actually has stronger evidence. It 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 object on 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 will give them a conditional probability measure. And the other thing is that they’re using that evidence to get to idea, get to a hypothesis about the world, that very unlikely to begin with. And in studies we’ve just been doing in lab, similar studies, we’ve show that four year-olds are actually better at finding out an unlikely hypothesis than 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, 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 a bunch of 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 Cristine did was use our Blicket Detectors. what she did was show children that yellow ones it go and red ones didn’t, and then she them an anomaly. And what you’ll see is that this boy will go through five hypotheses in the space of two minutes.
(Video) Boy: How about this? as the other side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and this nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s this light up. (Laughter) I don’t know.
AG: Every scientist recognize that expression of despair.
(Laughter)
Boy: Oh, it’s because this to be like this, and this needs to be this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now is 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 goes only to here, not here. Oh, the bottom of this has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s up. So when you put four. So you put on this one to make it light up and two 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 boy, but what Cristine discovered is this is actually quite typical. If look at the way children play, when you ask to explain something, what they really do is do a series experiments. This is actually pretty typical of four year-olds.
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Well, what’s it like to be this kind creature? What’s it like to be one of these brilliant butterflies who 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 were at all. And I think just the opposite is true. I think babies and children actually more conscious than we are as adults. Now here’s what we know how adult consciousness works. And 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 consciousness of that thing that we’re attending becomes extremely bright and vivid, and everything else sort goes dark. And we even know something about the way the brain this.
So what happens when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a that makes a little part of our brain much flexible, more plastic, better at learning, and shuts down activity in all rest of 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 seem have more of a lantern of consciousness than a spotlight consciousness. So babies and young children are very bad narrowing down to just one thing. But they’re very good at taking in lots of information lots of different sources at once. And if you actually look their brains, you see that they’re flooded with these that are really good at inducing learning and plasticity, the inhibitory parts haven’t come on yet. So when we say that babies and young children are bad paying attention, what we really mean is that they’re bad at not paying attention. So they’re at getting rid of all the interesting things that could tell something and just looking at the thing that’s important. That’s kind of attention, the kind of consciousness, that we might expect those butterflies who are designed to learn.
Well if we want to think a way of getting a taste of that kind of baby consciousness as adults, I think the best is think about cases where we’re put in a new that we’ve never been in before — when we fall in love 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 days in Paris 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 baby neurotransmitters. So what’s it like to be baby? It’s like being in love in Paris for first time after you’ve had three double-espressos. (Laughter) That’s a way to be, but it does tend to leave you waking crying at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say much about how wonderful babies are. It’s good to be a grownup. We can do things tie our shoelaces and cross the street by ourselves. And it makes sense that we put 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)