What is on in this baby’s mind? If you’d asked people 30 years ago, most people, including psychologists, would have said that baby was irrational, illogical, egocentric — that he couldn’t the perspective of another person or understand cause and effect. the last 20 years, developmental 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 give just one example of this. One thing that this could be thinking about, that could be going on in his mind, trying to figure out what’s going on in the mind of that other baby. After all, of the things that’s hardest for all of us to do to figure out what other people are thinking and feeling. And maybe the hardest thing all is to figure out that what other people and feel isn’t actually exactly like what we think feel. Anyone who’s followed politics can testify to how that is for some people to get. We wanted to know if babies and 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 to tell you what thinks, what you’ll get is a beautiful stream of monologue about ponies and birthdays and things like that. So how do we ask them the question?
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Well it turns that the secret was broccoli. What we did — Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: one bowl of 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 what Betty was to take a little taste of food from bowl. And she would act as if she liked or she didn’t. So half the time, she acted as if she liked the crackers and didn’t the broccoli — just like a baby and any sane person. But half the time, what she would do is take a little bit of the broccoli 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. I the crackers. Eww, yuck.” So she’d act as if what wanted was just the opposite of what the babies wanted. We did 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 liked or what she liked? And the remarkable was that 18 month-old babies, just barely walking and talking, would her the crackers if she liked the crackers, but would give her the broccoli if she liked the broccoli. On the hand, 15 month-olds would stare at her for a long time if she acted as if she the broccoli, like they couldn’t figure this out. But then after they stared for a time, they would just give her the crackers, what they thought everybody must like. So there are two remarkable things about this. The first one is that these little 18 month-old babies have already this really profound fact about human nature, that we don’t always the same thing. And what’s more, they felt that they actually do 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 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 just one of hundreds and hundreds of studies over last 20 years that’s actually demonstrated it.
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The question you might ask though is: Why children learn so much? And how is it possible for them to learn so in such a short time? I mean, after all, if you look babies superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, because we to put so much time and energy into just keeping them alive. But if turn to evolution for an answer to this puzzle of why we spend so time taking care of useless babies, it turns out there’s actually an answer. If we look across many, many species of animals, not just us primates, but also including other mammals, birds, even like kangaroos and wombats, it turns out that there’s relationship between how long a childhood a species has and how their brains are compared to their bodies and how and flexible they are.
And sort of the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows other corvidae, ravens, rooks and so forth, are incredibly 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 our friend the domestic chicken. And chickens and ducks and and turkeys are basically as dumb as dumps. So they’re very, very good pecking for grain, and they’re not much good at doing anything else. Well it turns out that babies, the New Caledonian crow babies, are fledglings. They depend on moms to drop worms in their little open mouths as long as two years, which is a really long time in the life of a bird. Whereas chickens are actually mature within a couple of months. So childhood is the reason why the crows up on the cover of Science and the chickens end in the soup pot.
There’s something about that long childhood that to be connected to knowledge and learning. Well what kind of explanation could we have this? Well some animals, like the chicken, seem to beautifully suited to doing just one thing very well. they seem to be beautifully suited to pecking grain in one environment. Other creatures, the crows, aren’t very good at doing anything in particular, they’re extremely good at learning about laws of different environments.
And course, we human beings are way out on the end of distribution like the crows. We have bigger brains relative to bodies by far than any other animal. We’re smarter, we’re more flexible, we can learn more, we 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 the babies of any other species. My son is 23. (Laughter) And at least until they’re 23, we’re popping those worms into those little open mouths.
All right, why would we see this correlation? Well idea is that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it has big disadvantage. And that one big 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 you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” want to know all that before the mastodons actually show up. the way the evolutions seems to have solved that problem is with a of division of labor. So the idea is that have this early period when we’re completely protected. We don’t have to anything. All we have to do is learn. And then as adults, we 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 of thinking about it is that babies and young children are like the research and development division of human species. So they’re the protected blue sky guys who just have to out and learn and have good ideas, and we’re production and marketing. We have to take all those that we learned when we were children and actually put them to use. Another way thinking about it is instead of thinking of babies and children being like defective grownups, we should think about them being a different developmental stage of the same species — kind of caterpillars and butterflies — except that they’re actually the brilliant who are flitting around the garden and exploring, and we’re 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 this evolutionary story say children are for learning, that’s what they’re for — we might expect that would have 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 lot better. And there’s a revolution in our understanding of machine learning recently. And it all depends the ideas of this guy, the Reverend Thomas Bayes, 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. So what scientists do they have a hypothesis that they think might be likely to start with. They go out test it against the evidence. The evidence makes them change hypothesis. Then they test that new hypothesis and so on and so forth. And what Bayes showed was mathematical way that you could do that. And that mathematics is at the core of the best machine programs that we have now. And some 10 years ago, I suggested that babies might 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 think those babies are making complicated calculations with conditional probabilities that they’re revising figure out how the world works. All right, now that might seem like an even taller order to 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 test we used a machine that we have called the Blicket Detector. This a box that lights up and plays music when you some things on it and not others. And using this very machine, my lab and others have done dozens of studies showing just good babies are at learning about the world. Let me mention one that we did with Tumar Kushner, my student. If showed you this detector, you would be likely to to begin with that the way to make the detector would be to put a block on top of the detector. But actually, this detector in a bit of a strange way. Because if you wave a over the top of the detector, something you wouldn’t ever think of to begin with, detector will actually activate two out of three times. Whereas, you do the likely thing, put the block on the detector, it will activate two out of six times. So the unlikely hypothesis actually has stronger evidence. It looks as if waving is a more effective strategy than the other strategy. 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 object on top of the detector.
Now there are things that are really interesting about this. The 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 that will give them conditional probability measure. And the other interesting thing is 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 that four year-olds are actually better at finding out unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using statistics to find out about the world, but all, scientists also do experiments, and we wanted to see if children doing experiments. When children do experiments we call it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown playing around is really a kind of experimental research program. Here’s one Cristine Legare’s lab. What Cristine did was use our Detectors. And what she did was show children that yellow ones made it go and red ones didn’t, then she showed them an anomaly. And what you’ll see is that this little boy will through five hypotheses in the space of two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has just been falsified.
(Laughter)
Boy: one lighted up, and this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this up. (Laughter) I don’t know.
AG: Every scientist will that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs to like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this his next idea. He told the experimenter to do this, to putting it out onto the other location. Not working either.
Boy: Oh, because the light only to here, not here. Oh, the bottom of this box has electricity in here, 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 one to make it light up and two on this one to it light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and little boy, but what Cristine discovered is this is quite typical. If you look at the way children play, when ask them to explain something, what they really do do a series of experiments. This is actually pretty typical four year-olds.
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Well, what’s it like to be kind of creature? What’s it like to be one of these brilliant butterflies who test five hypotheses in two minutes? Well, if you go back to those psychologists and philosophers, a of them have said that babies and young children were barely conscious they were conscious at all. And I think just the opposite is true. I babies and children are actually more conscious than we are adults. Now here’s what we know about how adult works. And adults’ attention and consciousness look kind of like spotlight. So what happens for adults is we decide something’s relevant or important, we should pay attention to it. Our consciousness of thing that we’re attending to becomes extremely bright and vivid, and else sort of goes dark. And we even know about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, the sort of 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. we have a very focused, purpose-driven kind of attention. If we look at and young children, we see something very different. I think babies and young children seem to 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 neurotransmitters that are really good at inducing and plasticity, and the inhibitory parts haven’t come on yet. So when 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 all the interesting things that could tell them something and just looking at thing that’s important. That’s the kind of attention, the of consciousness, that we might expect from those butterflies who are designed 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 cases where we’re put in a new that we’ve never been in before — when we in love with someone new, or when we’re in new city for the first time. And what happens then is not that our consciousness contracts, expands, so that those three days in Paris seem to be more of consciousness and experience than all the months of being a walking, talking, meeting-attending zombie back home. And by the way, that coffee, that wonderful coffee you’ve been downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it like to a baby? It’s like being in love in Paris the first time after you’ve had three double-espressos. (Laughter) That’s a way to be, but it does tend to leave you waking up 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 to be a grownup. can do things like tie our shoelaces and cross the street by ourselves. And it makes sense that put a lot of effort into making babies think like adults do. if what we want is to be like those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults start thinking more like children.
(Applause)