What is going on this baby’s mind? If you’d asked people this 30 years ago, people, including 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. In the last 20 years, science has completely overturned that picture. So in some ways, we think this baby’s thinking is like the thinking of the brilliant scientists.
Let me give you just one example of this. One thing this baby could be thinking about, that could be going on in mind, is trying to figure out what’s going on in the of that other baby. After all, one of the things that’s hardest for all of to do is to figure out what other people are 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 to how hard that is for some people to get. We wanted to if babies and young children could understand this really profound about other people. Now the question is: How could we them? Babies, after all, can’t talk, and if you ask three year-old to tell you what he thinks, what you’ll get is beautiful stream of consciousness monologue about ponies and birthdays and like that. So how do we actually ask them the question?
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Well turns out that the secret was broccoli. What we — Betty Rapacholi, who was one of my students, and — was actually to give the babies two bowls of food: one bowl of broccoli and one bowl of delicious goldfish crackers. Now all of babies, even in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take a little taste food from each bowl. And she would act as she liked it or she didn’t. So half the time, acted as if she liked the crackers and didn’t the broccoli — just like a baby and any other person. But half the time, what she would do is a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would a little bit of the crackers, and she’d go, “Eww, yuck, crackers. tasted the crackers. Eww, yuck.” So she’d act as what she wanted was just the opposite of what babies wanted. We did this with 15 and 18 month-old babies. And then she simply put her hand out and say, “Can you give me some?”
So question is: What would the baby give her, what they or what she liked? And the remarkable thing was 18 month-old babies, just barely walking and talking, would give her the if she liked the crackers, but they would give her broccoli if she liked the broccoli. On the other hand, 15 month-olds would stare at her for a time if she acted as if she liked the broccoli, like they couldn’t figure out. But then after they stared for a long time, 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 little 18 month-old babies have already discovered this really fact about human nature, that we don’t always want the same thing. And what’s more, felt that they should actually do 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 both know more and learn more than we ever would have thought. And this is just of hundreds and hundreds of studies over the last 20 years that’s actually it.
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The question you might ask though is: Why do learn so much? And how is it possible for to learn so much in such a short time? I mean, after all, you look at babies superficially, they seem pretty useless. And in many ways, they’re worse than useless, because we have to put so 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 taking care of babies, it turns out that there’s actually an answer. we look across many, many different species of animals, not us primates, but also including other mammals, birds, even marsupials like and wombats, it turns out that there’s a relationship how long a childhood a species has and how big their brains are compared to bodies and how smart and flexible they are.
And sort of the posterbirds for this are the birds up there. On one side is a Caledonian crow. And crows and other corvidae, ravens, rooks so forth, are incredibly smart birds. They’re as smart as chimpanzees some respects. And this is a bird on the cover of science who’s learned how to use tool to get food. On the other hand, we our friend the domestic chicken. And chickens and ducks and geese and turkeys are basically as as dumps. So they’re very, very good at pecking grain, and they’re not much good at doing anything else. Well turns out that the babies, the New Caledonian crow babies, are fledglings. They depend on their moms to drop in their little open mouths for as long as two years, which is a long time in the life of a bird. Whereas the chickens are actually mature a couple of months. So childhood is the reason why the crows end up the cover of Science and the chickens end up in soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what kind 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 pecking grain in one environment. Other creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about laws of different environments.
And of course, we human are way out on the end of the distribution the crows. We have bigger brains relative to our bodies by far any other animal. We’re smarter, we’re more flexible, we can learn more, we survive more different environments, we migrated to cover the world and even to outer space. And our babies and children are dependent on for much longer than the babies of any other species. My son is 23. (Laughter) at least until they’re 23, we’re still popping those worms those little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in world, but it has one big disadvantage. And that one disadvantage is that, until you actually do all that learning, you’re going be helpless. So you don’t want to have the mastodon charging at and be saying to yourself, “A slingshot or maybe a spear might work. would actually be better?” You want to know all that before the mastodons actually show up. And the the evolutions seems to have solved that problem is a kind of division of labor. So the idea is that we this early period when we’re completely protected. We don’t have to do anything. All 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 in the world.
So one way of thinking about it is babies and young children are like the research and development of the human species. So they’re the 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 and actually them to use. Another way of thinking about it is instead of of babies and children as being like defective grownups, should think about them as being a different developmental stage of the same species — kind like caterpillars and butterflies — except that they’re actually the brilliant butterflies who are flitting around the and exploring, and we’re the caterpillars who are inching along our narrow, grownup, adult path.
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If is true, if these babies are designed to learn — and 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 the most powerful learning computer on the planet. But real computers are actually getting be a lot better. And there’s been a revolution in our of machine learning recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician mathematician in the 18th century. And essentially what Bayes did was to provide a mathematical way using probability to 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 out and test it against the evidence. The evidence makes them that hypothesis. Then they test that new hypothesis and so on so forth. And what Bayes showed was a mathematical way that you could do that. And that is at the core of the best machine learning that we have now. And some 10 years ago, suggested that babies might be doing the same 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 to figure out how the world works. All right, that 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 be that children are statistics?
So to test this we used a machine that we have called the Detector. This is a box that lights up and plays music you put some things on it and not others. using this very simple machine, my lab and others done dozens of studies showing just how good babies are at learning about world. Let me mention just one that we did with Kushner, my student. If I showed you this detector, you would likely to think to begin with that the way to make detector go would be to put a block on of the detector. But actually, this detector works in a bit of a strange way. Because if wave a block over the top of the detector, something you wouldn’t ever of to begin with, the detector will actually activate two out three times. Whereas, if you do the likely thing, the block on the detector, it will only activate two out of six times. So unlikely hypothesis actually has stronger evidence. It looks as if the waving a more effective strategy than the other strategy. So did just this; we gave four year-olds this pattern of evidence, and we just asked to make it go. And sure enough, the four year-olds used the to wave the object on top of the detector.
Now there are two things that are really interesting this. The first one is, again, remember, these are year-olds. They’re just learning how to count. But unconsciously, they’re doing quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re using that evidence get to an idea, get to a hypothesis about the world, that seems very to begin with. And in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better 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 about the world, but after all, scientists also do experiments, and we wanted to see if children are experiments. When children do experiments we call it “getting into everything” or “playing.”
And there’s been a bunch of interesting studies recently 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. And she did was show children that yellow ones made go and red ones didn’t, and then she showed an anomaly. And what you’ll see is that this little boy will go five hypotheses in the space of two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making 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 this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told the experimenter do this, to try putting it out onto the other location. Not working either.
Boy: Oh, the light goes only to here, not here. Oh, the bottom this box has 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 up and two this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and articulate little boy, what Cristine discovered is this is actually quite typical. If you look the way children play, when you ask them to explain something, what really do is do a series of experiments. This actually pretty typical of four year-olds.
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Well, what’s it to be this kind of creature? What’s it like be one of these brilliant butterflies who can test hypotheses in two minutes? Well, if you go back 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 are actually conscious than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens adults is we decide that something’s relevant or important, we pay attention to it. Our consciousness of that thing that we’re to becomes extremely bright and vivid, and everything else sort of goes dark. And even know something about the way the brain does this.
So what happens when pay attention is that the prefrontal cortex, the sort of executive part of our brains, sends signal that makes a little part of our brain much flexible, more plastic, better at learning, and shuts down in all the rest of our brains. So we have a focused, purpose-driven kind of attention. If we look at babies and young children, we something very different. I think babies and young children seem to have more of a lantern of consciousness a spotlight of consciousness. So babies and young children are very bad narrowing down to just one thing. But they’re very good taking in lots of information from lots of different at once. And if you actually look in their brains, you see that they’re flooded these neurotransmitters that are really good at inducing learning and plasticity, and the inhibitory 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 at not paying attention. So they’re bad at getting of all the interesting things that could tell them something and 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 to learn.
Well if we want to think about a of getting a taste of that kind of baby consciousness as adults, I the best thing is think about cases where we’re in a new situation that we’ve never been in before — we fall in love with someone new, or when we’re in a new city for first time. And what happens then is not that consciousness contracts, it expands, so that those three days in Paris seem to be more of consciousness and experience than all the months of being walking, talking, faculty meeting-attending zombie back home. And by the way, coffee, that wonderful coffee you’ve been drinking downstairs, actually the effect 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 a fantastic way to be, it does tend to leave you waking up crying 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. can do things like tie our shoelaces and cross the street by ourselves. And it makes that we put a lot of effort into making think like adults do. But if what we want is to be those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some the time we should be getting the adults to start thinking more children.
(Applause)