What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would have 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, we that 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 his mind, is trying to figure out what’s going on in mind of that other baby. After all, one of the things that’s hardest for of us to do is to figure out what other people thinking and feeling. And maybe the hardest thing of all is to out that what other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can testify to how hard that for some people to get. We wanted to know babies and young children could understand this really profound thing about other people. the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old 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 question?
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Well it turns out that the secret broccoli. What we did — Betty Rapacholi, who was one of my students, and — was actually to 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 then Betty did was to take a little taste of food each bowl. And she would act as if she liked it she didn’t. So half the time, she acted as if she liked crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what would do is take a little bit of the broccoli go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a little of the crackers, and she’d go, “Eww, yuck, crackers. I the crackers. Eww, yuck.” So she’d act as if what she wanted was the opposite of what the babies wanted. We did this 15 and 18 month-old babies. And then she would simply put her hand out and say, “Can give me some?”
So the question is: What would the give her, what they liked or what she liked? And the thing was that 18 month-old babies, just barely walking and talking, would give her the crackers she liked the crackers, but they would give her the broccoli if she liked the broccoli. the other hand, 15 month-olds would stare at her a long time if she acted as if she the broccoli, like they couldn’t figure this out. But then after they stared a long time, they would just give her the crackers, what they thought everybody like. So there are two really remarkable things about this. The first one is that little 18 month-old babies have already discovered this really profound about human nature, that we don’t always want the same thing. what’s more, they felt that they should actually do things to help people get what they wanted.
Even more remarkably though, 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 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 of studies over the last 20 years that’s actually demonstrated it.
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question you might ask though is: Why do children learn so much? And how is possible for them to learn so much in such a short time? I mean, all, if you look at babies superficially, they seem pretty useless. And in many ways, they’re worse than useless, because we have to put so much time energy into just keeping them alive. But if we to evolution for an answer to 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, marsupials like kangaroos and wombats, it turns out that there’s a between how long a childhood a species has and how big their brains are compared to their bodies how smart and flexible they are.
And sort of the posterbirds for this idea are the birds there. On one side is a New Caledonian crow. And crows and other corvidae, ravens, and 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 to use a tool to get food. On the other hand, we have our friend the chicken. And chickens and ducks and geese and turkeys are as dumb as dumps. So they’re very, very good at pecking for grain, and they’re much good at doing anything else. Well it turns out the babies, the New Caledonian crow babies, are fledglings. depend on their moms to drop worms in their little open mouths for as long as years, which is a really long time in the life of a bird. Whereas chickens are actually mature within a couple of months. So is the reason why the crows end up on cover of Science and the chickens end up in soup pot.
There’s something about that long childhood that seems be connected to knowledge and learning. Well what kind of explanation could we for this? Well some animals, like the chicken, seem to be beautifully suited to doing just thing 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 anything in particular, but they’re 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 far 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 even go outer space. And our babies and children are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into those little open mouths.
All right, why would see this correlation? Well an idea is that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it has one big disadvantage. And that one disadvantage is that, until you actually do all that learning, you’re going to helpless. So you don’t want to have the mastodon charging you and be saying to yourself, “A slingshot or maybe a spear work. Which would actually be better?” You want to know that before the mastodons actually show up. And the the evolutions seems to have solved that problem is with a kind 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 we have to do learn. And then as adults, we can take all those things that we learned when we were babies children and actually put them to work to do out there in the world.
So one way of about it is that babies and young children are like the research development division of the human 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 have to take all ideas that we learned when we were children and put them to use. Another way of thinking about it is instead of thinking of babies children as being like defective grownups, we should think about as being a different developmental stage of the same species — kind of like and butterflies — except that they’re actually the brilliant who are flitting around the garden and exploring, and we’re the caterpillars who are inching along narrow, grownup, adult path.
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If this is true, if babies are designed to learn — and this evolutionary story would children are for learning, that’s what they’re for — we expect that they would have really powerful learning mechanisms. And in fact, the baby’s seems to be the most powerful learning computer on the planet. But real computers are actually to be a lot better. And there’s been a revolution our understanding of machine learning recently. And it all depends on the ideas this guy, the Reverend Thomas Bayes, who was a statistician and mathematician the 18th century. And essentially what Bayes did was to provide a mathematical way using probability theory characterize, describe, the 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 it against the evidence. The evidence makes them change hypothesis. Then they test that new hypothesis and so and so forth. And what Bayes showed was a mathematical way you could do that. And that mathematics is at the core the best machine learning programs that we have now. some 10 years ago, I suggested that babies might doing the same thing.
So if you want to what’s going on underneath those beautiful brown eyes, I it actually looks something like this. This is Reverend Bayes’s notebook. So I think babies are actually making complicated calculations with conditional probabilities that they’re revising to figure out the world works. All right, now that might seem like an even taller order actually demonstrate. Because after all, if you ask even grownups about statistics, they look stupid. How could it be that children are doing statistics?
So to this 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. using this very simple machine, my lab and 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 the detector go would be to put a on top of the detector. But actually, this detector works 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 detector actually activate two out of three times. Whereas, if you do the likely thing, put block on the detector, it will only activate two of six times. So the unlikely hypothesis actually has evidence. It looks as if the waving is a more effective strategy than other strategy. So we did just this; we gave four year-olds this pattern of evidence, and just asked them to make it go. And sure enough, the year-olds used the evidence to wave the object on top of detector.
Now there are two things that are really about this. The first one 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 thing is that they’re using that evidence to get to an idea, get to hypothesis about the world, that seems very unlikely to begin with. And studies we’ve just been doing in my lab, similar studies, we’ve show that four year-olds are actually at finding out an unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using statistics find out about the world, but after all, scientists do 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 been a bunch of interesting recently that have shown this playing around is really kind of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine was use our Blicket Detectors. And what 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 through five hypotheses in the of two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and this one nothing.
AG: Okay, he’s his experimental notebook out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every will recognize that expression of despair.
(Laughter)
Boy: Oh, it’s 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 next idea. He told the experimenter to do this, to try putting it onto the other location. Not working either.
Boy: Oh, the light goes only to here, not here. Oh, bottom of 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 on this one to it light up.
AG: Okay,there’s his fifth hypothesis.
Now is a particularly — that is a particularly adorable and little boy, but what Cristine 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 pretty typical of four year-olds.
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Well, what’s it to be this kind of creature? What’s it like to be one of brilliant butterflies who can test five hypotheses in two minutes? Well, you go back to those psychologists and philosophers, a of them have said that babies and young children were barely conscious if were conscious at all. And I think just the opposite is true. I think and children are actually more conscious than we are as adults. here’s what we know about how adult consciousness works. And adults’ attention consciousness look kind of like a spotlight. So what happens for adults is we decide that something’s relevant 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 of goes dark. And we even 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 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 of attention. we look at babies and young children, we see something very different. I think babies and young seem to have more of a lantern of consciousness than a spotlight consciousness. So babies and young children are very bad at narrowing down to just thing. But they’re very good at taking in lots information from lots of different sources at once. And if you actually look in their brains, you see they’re flooded with these neurotransmitters that are really good at learning and plasticity, and the inhibitory parts haven’t come on yet. So when we say babies and young children are bad at paying attention, what we mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting things that could tell them something and just looking the thing that’s important. That’s the kind of attention, the kind of consciousness, that we expect from those butterflies who are designed to learn.
Well if we to think about a way of getting a taste of that kind of consciousness as adults, I think the best thing is think cases where we’re put in a new situation that we’ve been in before — when we fall in love with someone new, when we’re in a new city for the first time. what happens then is not that our consciousness contracts, it expands, so that those three in Paris seem to be more full of consciousness and experience than all the months of a walking, talking, faculty meeting-attending zombie back home. And by way, that coffee, that wonderful coffee you’ve been drinking downstairs, mimics the effect of those baby neurotransmitters. So what’s it like to be a baby? It’s like being love in Paris for the first time after you’ve three double-espressos. (Laughter) That’s a fantastic way to be, but it does 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 how babies are. It’s good to be a grownup. We can do things like tie our and cross the street by ourselves. And it makes sense that we put a lot of effort into babies think 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 to start thinking more like children.
(Applause)