What is going on this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, have 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, science has completely overturned that picture. So in some ways, we that this baby’s thinking is like the thinking of the most brilliant scientists.
Let me 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 in the mind of that other baby. After all, one of the things that’s for all of us to do is to figure out other people are thinking and feeling. And maybe the hardest thing of all is to figure out that other people think and feel isn’t actually exactly like what we think and feel. Anyone who’s followed can testify to how hard that is for some people to get. wanted to know if babies and young children could understand this really profound thing about other people. Now question is: How could we ask them? Babies, after all, can’t talk, if you ask a three year-old to tell you he thinks, what you’ll get is a beautiful stream of consciousness monologue about and birthdays and things like that. So how do actually ask them the question?
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Well it turns out that the 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 raw broccoli 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) But then Betty did was to take a little taste of food from each bowl. And she act as if she liked it or she didn’t. So half the time, acted as if she liked the crackers and didn’t like the broccoli — like a baby and any other sane person. But half the time, what she would do take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted broccoli. Mmmmm.” And then she would take a little 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 the babies wanted. We did this with 15 and 18 month-old babies. And then she would simply put her out and say, “Can you give me some?”
So question is: What would the baby give her, what liked or what she liked? And the remarkable thing was that 18 month-old babies, just barely and talking, would give her the crackers if she the crackers, but they would give her the broccoli if she liked the broccoli. the other hand, 15 month-olds would stare at her for a long if she acted as if she liked the broccoli, like they couldn’t this out. But then after they stared for a long time, they would give her the crackers, what they thought everybody must like. So there two really remarkable things about this. The first one is that little 18 month-old babies have already discovered this really profound fact about human nature, that don’t always want the same 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 months 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 20 years that’s actually demonstrated it.
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The question you might though is: Why do children learn so much? And how is it possible for them learn so much in such a short time? I mean, after all, if you at babies superficially, they seem pretty useless. And actually in many ways, they’re than useless, because we have to put so much time energy into just keeping them alive. But if we turn to for an answer to this puzzle of why we spend so time taking care of useless babies, it turns out that there’s actually answer. If we look across many, many different species of animals, just us primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, it turns out there’s a relationship between how long a childhood a species and how big their brains are compared to their bodies how smart and flexible they are.
And sort of posterbirds for this idea are the birds up there. On one side is New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as as chimpanzees in some respects. And this is a bird on cover of science who’s learned how to use a to get food. On the 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, very at pecking for grain, and they’re not much good at doing anything else. Well it turns that the babies, the New Caledonian crow babies, are fledglings. They depend on moms to drop worms in their little open mouths for long as two years, which is a really long time in the of a bird. Whereas the chickens are actually mature within couple of months. So childhood is the reason why the crows end on the cover of Science and the chickens end in the soup pot.
There’s something about that long childhood seems to be connected to knowledge and learning. Well kind of 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 to 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 course, we human beings are way out on the of the distribution like the crows. We have bigger relative to our bodies by far than any other animal. We’re smarter, we’re more flexible, can learn more, we survive in more different environments, migrated to cover the world and even go to space. And our babies and children are dependent on us for longer than the babies of any other species. My son is 23. (Laughter) And least until they’re 23, we’re still popping those worms those little open mouths.
All right, why would we this correlation? Well an idea is that that strategy, that learning strategy, is extremely powerful, great strategy for getting on in the world, but it has one big disadvantage. that one big disadvantage is that, until you actually all that 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 be better?” You to know all that before the mastodons actually show up. the way the evolutions seems to have solved that problem is with kind of division of labor. So the idea is that we this early period when we’re completely protected. We don’t have do anything. All we have to do is learn. And then adults, we can take all those things that we learned when we were babies and children actually put them to work to do things out there in the world.
So one way of about it is that babies and young children are like the and development division of the human species. So they’re the protected blue sky guys just have to go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas that we learned when we were and actually put them to use. Another way of thinking about it is instead thinking of babies and children as being like defective grownups, we should think them as being a different developmental stage of the same — 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 our narrow, grownup, adult path.
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If this is true, if these babies are designed learn — and this evolutionary story would say children are for learning, that’s they’re for — we might expect that they would really powerful learning mechanisms. And in fact, the baby’s brain seems to be most powerful learning computer on the planet. But real are actually getting to be a lot better. And there’s been a revolution in our of machine learning recently. And it all depends on the ideas of this guy, the Reverend Bayes, who was a statistician and mathematician in the 18th century. And essentially what did was to provide a mathematical way using probability to characterize, describe, the way that scientists find out about the world. what scientists do is they have a hypothesis that they think might be to start with. They go out and test it against evidence. The evidence makes them change that hypothesis. Then they that new hypothesis and so on and so forth. And what Bayes was a mathematical way that you could do that. that mathematics is at the core of the best learning programs that we have now. And some 10 ago, I suggested that babies might be doing the same thing.
So if you want to what’s going on underneath 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 that they’re revising to figure out how the world works. All right, now that seem like an even taller order to actually demonstrate. Because after all, if you ask grownups about statistics, they look extremely stupid. How could it that children are doing statistics?
So to test this used a machine that we have called the Blicket Detector. This is box that lights up and plays music when you some things on it and not others. And using this very simple machine, my lab and others have dozens of studies showing just how good babies are at learning about world. Let me mention 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 the to make the detector go would be to put a block on top the detector. But actually, this detector works in a bit of a strange way. if you wave a block over the top of the detector, something wouldn’t ever think of to begin with, the detector will actually two out of three times. Whereas, if you do the thing, put the block on the detector, it will only two out of six times. So the unlikely hypothesis actually stronger evidence. It looks as if the waving is a more effective strategy than the other strategy. we did just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And sure enough, the four year-olds used evidence to wave the object on top of the detector.
Now there are two that are really interesting about this. The first one is, again, remember, are 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. the other interesting 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 an unlikely hypothesis than adults are when we give them exactly the same task. So these circumstances, the children are using statistics to find out the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. When children do experiments we it “getting into everything” or else “playing.”
And there’s been a of interesting studies recently that have shown this playing is really a kind of experimental research program. Here’s one from Cristine Legare’s lab. Cristine did was use our Blicket Detectors. And what did was show children that yellow ones made it go and ones didn’t, and then she showed them an anomaly. what you’ll see is that this little boy will go five hypotheses in the space of two minutes.
(Video) Boy: How this? Same as the other side.
Alison Gopnik: Okay, his first hypothesis has just been falsified.
(Laughter)
Boy: This one up, and this one nothing.
AG: Okay, he’s got experimental notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every scientist will that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, and this needs be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told experimenter to do this, to try putting it out the other location. Not working either.
Boy: Oh, because light goes only to here, not here. Oh, the bottom of box has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. when you put four. So you put four on this one to make light up and two on this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that is a particularly adorable articulate little boy, but what Cristine discovered is this is actually quite typical. If you look at the children play, when you ask them to explain something, they really do is do a series of experiments. 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 can test five in two minutes? Well, if you go back to those psychologists and philosophers, a lot of have said that babies and young children were barely conscious they were conscious at all. And I think just the opposite true. I think babies and children are actually more conscious we are as adults. Now here’s what we know how adult consciousness works. And adults’ attention and consciousness look of like a spotlight. So what 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 to becomes extremely bright and vivid, everything else sort of goes dark. And we even know something about the way the does this.
So what happens when we pay attention is that the prefrontal cortex, the sort executive part of our brains, sends a signal that makes little part of our brain much more flexible, more plastic, at learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven kind of attention. If look at babies and young children, we see something very different. I think babies young children seem 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 at taking in lots of information from lots of different at once. And if you actually look in their brains, see that they’re flooded with these neurotransmitters that are good at inducing learning and plasticity, and the inhibitory parts haven’t on yet. So when we say that babies and young are bad at paying attention, what we really mean that they’re bad at not paying attention. So they’re bad at getting rid of all the things that could tell them something and just looking at the thing that’s important. That’s kind of attention, the kind of consciousness, that we might expect from those butterflies who designed to learn.
Well if we want to think about a of getting a taste of that kind of baby consciousness adults, I think the best thing is think about where we’re put in a new situation that we’ve been in before — when we fall in love with someone new, or we’re in a new city for the first time. And what then is not that our consciousness contracts, it expands, so those three days in Paris seem to be more full of and experience than all the months of being a walking, talking, faculty meeting-attending zombie back home. And by way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics the effect of baby neurotransmitters. So what’s it like to be a baby? It’s like in love in Paris for the first time after you’ve had double-espressos. (Laughter) That’s a fantastic way to be, but it does tend to leave you up crying at three o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want to 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 we want is be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of the we should be getting the adults to start thinking like children.
(Applause)