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 he couldn’t 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, think that this baby’s thinking is like the thinking the most brilliant scientists.
Let me 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, one of things that’s hardest for all of us to do is to out what other people are thinking and feeling. And maybe the hardest of all is to figure out that what other people and feel isn’t actually exactly like what we think and feel. Anyone who’s followed politics can testify to hard that is for some people to get. We wanted to know if and young children could understand this really profound thing about other people. Now the question is: How we ask them? Babies, after all, can’t talk, and if you ask a year-old to tell you what he thinks, what you’ll get is beautiful stream 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 the secret was broccoli. we did — Betty Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, the crackers and don’t like the raw broccoli. (Laughter) But then what Betty did was take a little taste of food from each bowl. And she act as if she liked it or she didn’t. So half time, she acted as if she liked the crackers and didn’t like the broccoli — just a baby and any other sane person. But half the time, what she would is take a little bit of the broccoli and go, “Mmmmm, broccoli. tasted the broccoli. Mmmmm.” And then she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d act 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 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 that 18 month-old babies, just walking and talking, would give her the crackers if she liked the crackers, but they would give 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 for a time, they would just give her the crackers, what 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 we don’t always want same thing. And what’s more, they felt that they actually do things to help other people get what they wanted.
Even remarkably 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 when they 15 months old. So children both know more and learn more than we would have thought. And this is just one of hundreds and of studies over the last 20 years that’s actually demonstrated it.
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The question you ask though is: Why do children learn so much? And is it possible for them to learn so much such a short time? I mean, after all, if look at babies superficially, they seem pretty useless. And actually in many ways, they’re than useless, because we have to put so much time and into just keeping them alive. But if we turn to for an answer to this puzzle of why we spend so much time care of useless babies, it turns out that there’s an answer. If we look across many, many different of animals, not just us primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a relationship between how a childhood 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 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 in some respects. this is a bird on the cover of science who’s learned how to use a to get food. On the other hand, we have friend the domestic chicken. And chickens and ducks and geese and turkeys 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 out that the babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little open for as long as two years, which is a really long time in the life of bird. Whereas the chickens are actually mature within a couple months. So childhood is the reason why the crows end up on the of Science and the chickens end up in the soup pot.
There’s something about long childhood that seems to be connected to knowledge and learning. Well what kind of could we have for this? Well some animals, like the chicken, seem to be beautifully 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 extremely at learning about laws of different environments.
And of course, we human beings way out on the end of the distribution like crows. We have bigger brains relative to our bodies by than any other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to cover the world and go to outer 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 into those little open mouths.
All right, would we see this correlation? Well an idea is that strategy, that learning strategy, is an extremely powerful, great strategy for getting on the world, but it has one big disadvantage. And that one big disadvantage is that, until actually do all that learning, you’re going to be helpless. you don’t want to have the 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. And way the evolutions seems to have solved that problem is with kind of division of labor. So the idea is that we have this early when we’re completely protected. We don’t have to do anything. All we have to do is learn. And then adults, we can take all those things that we learned when were babies and children and actually put them to work do things out there in the world.
So one of thinking about it is that babies and young are like the research and development division of the species. So they’re the protected blue sky guys who just have go out and learn and have good ideas, and we’re production and marketing. We to take all those ideas that we learned when we children and actually put them to use. Another way thinking about it is instead of thinking of babies and children as being defective grownups, we should think about them as being different developmental stage of the same species — kind of caterpillars and butterflies — except that they’re actually the brilliant butterflies who are 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, if these are designed to learn — and this evolutionary story say children are for learning, that’s what they’re for — we might expect that they would really powerful learning mechanisms. And in fact, the baby’s seems to be the most powerful learning computer on planet. But real computers are actually getting to be a better. And there’s been a revolution in our understanding of machine learning recently. And it all depends on ideas of this guy, the Reverend Thomas Bayes, who was a and mathematician in the 18th century. And essentially what Bayes was to provide a mathematical way using probability theory to characterize, describe, way that scientists find out about the world. So scientists do is they have a hypothesis that they might be likely to start with. They go out and test against the evidence. The evidence makes them change that hypothesis. Then they test 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 machine learning programs that we 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 think those are actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, now that might seem like an even order to actually demonstrate. Because after all, if you ask even grownups statistics, they look extremely stupid. How could it be that children are doing statistics?
So to test this used a machine that we have called the Blicket Detector. This is a box lights up and plays music when you put some on it and not others. And using this very simple machine, my lab others have done dozens of studies showing just how babies are at learning about the world. Let me mention just one that we did with Tumar Kushner, student. If I showed you this detector, you would be likely think to begin with that the way to make detector go would be to put a block on top of the detector. But actually, 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 think of 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 out of six times. So the unlikely hypothesis actually has stronger evidence. It as if the waving is a more effective strategy than the other strategy. So did just this; we gave four year-olds this pattern of evidence, and we asked them to make it go. And sure enough, the year-olds used the evidence to wave the object on top of the detector.
Now there two things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning how count. But unconsciously, they’re doing these quite complicated calculations that give them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, get a 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 adults are we give them exactly the same task. So in circumstances, the children are using statistics to find out about 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 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 Cristine did use our Blicket Detectors. And what she did was children that yellow ones made it go and red didn’t, and then she showed 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 this? Same as the other side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and 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 recognize that of despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, 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 goes only to here, not here. Oh, the bottom of this box has electricity in here, but doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So 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 actually quite typical. If you look at the way play, when you ask them to explain something, what they really is do a series of experiments. This is actually typical of four year-olds.
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Well, what’s it like be this kind of creature? What’s it like to be one of these brilliant butterflies 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 were conscious 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 about 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 relevant or important, we should pay to it. Our consciousness of that thing that we’re attending becomes extremely bright and vivid, and everything else sort of dark. And we even know something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, the sort executive part of our brains, sends a signal that makes a part of our brain much more flexible, more plastic, better at learning, and down activity in all the rest of our brains. So have a very focused, purpose-driven kind of attention. If we look babies and young children, we see something very different. I think babies and young children seem to have of a lantern of consciousness than a spotlight of consciousness. So babies and children are very bad at narrowing down to just one thing. But they’re very good at in lots of information from lots of different sources at once. if you actually look in their brains, you see that they’re flooded these neurotransmitters that are really good at inducing learning plasticity, and the inhibitory parts haven’t come on yet. when we say that babies and young children are bad at paying attention, what we really mean is they’re bad at not paying attention. So they’re bad at getting rid of all interesting things that could tell them something and just looking at the thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from butterflies who are designed to learn.
Well if we want think about a way of getting a taste of that kind of baby as adults, I think the best thing is think about cases where we’re put in a new situation we’ve never been in before — when we fall love with someone new, or when we’re in a new for the first time. And what happens then is not our consciousness contracts, it expands, so that those three days in 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 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 double-espressos. (Laughter) That’s a fantastic way to be, but it tend to leave you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s good be a grownup. I don’t want to say too much about wonderful babies are. It’s good to be a grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that we a lot of effort into making babies think like adults do. But if what we want to be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of time we should be getting the adults to start thinking more children.
(Applause)