What is going in this baby’s mind? If you’d asked people this 30 ago, most people, including psychologists, would have said that this baby irrational, illogical, egocentric — that he couldn’t take the perspective of another person or understand and effect. In the last 20 years, developmental science has overturned that picture. So in some ways, we think that baby’s thinking is like the thinking of the most scientists.
Let me give you just one example of this. One thing this baby could be thinking about, that could be on in his mind, is trying to figure out what’s going on in the mind of that baby. After all, one of the things that’s hardest for all of us to do is to out what other people are 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 what 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 other people. Now the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old to you what he thinks, what you’ll get is a beautiful stream of consciousness monologue about 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 — Betty Rapacholi, was one of my students, and I — was actually give the babies two bowls of food: one bowl of raw broccoli 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 what Betty did to take a little taste of food from each bowl. And she would act as if liked it or she didn’t. So half the time, she as if she liked the crackers and didn’t like the broccoli — like a baby and any other sane person. But half time, what she would do is take a little bit of broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” then she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” she’d act as if what she wanted was just the of what the babies wanted. We did this with 15 and 18 month-old babies. And then would simply put her hand out and say, “Can you me some?”
So the question is: What would the give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just walking and talking, would give her the crackers if liked the crackers, but they 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 if she liked 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 thought everybody must like. So there are two really remarkable about this. The first one is that these little 18 month-old have already discovered this really profound fact about human nature, that we don’t always the same thing. And what’s more, they felt that should actually do things to help other people get they wanted.
Even more remarkably though, the 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 three from when they were 15 months old. So children both more and learn more than we ever would have thought. this is just one of hundreds and hundreds of 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 is it possible for them to learn so much such a short time? I mean, after all, if you look at superficially, they seem pretty useless. And actually in many ways, they’re worse useless, because we have to put so much time and energy just keeping them alive. But if we turn to evolution for an answer this puzzle of why we spend so much time taking care useless babies, it turns out that there’s actually an answer. If we look many, many different species of animals, not just us primates, but also including mammals, birds, even marsupials like kangaroos and wombats, it out that there’s a relationship between how long a childhood a has and how big their brains are compared to their bodies and how and flexible they are.
And sort of the posterbirds this idea are the birds up there. On one side is New Caledonian crow. And crows and other corvidae, ravens, rooks and so forth, are incredibly birds. They’re as smart as chimpanzees in some respects. And this is a bird on the cover of who’s learned how to use a tool to get food. On the other hand, we have friend the domestic chicken. And chickens and ducks and geese and turkeys are basically as dumb as dumps. they’re very, very good at pecking for grain, and they’re not much good at doing else. Well it turns out that the babies, the New Caledonian babies, are fledglings. They depend on their moms to drop worms in little open mouths for as long as two years, 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 the crows end up on the cover of Science and the chickens up in the soup pot.
There’s something about that long that seems to be connected to knowledge and learning. what kind of explanation could we have for this? Well some animals, like the chicken, seem to beautifully suited to doing just one thing very well. So they seem be beautifully suited to pecking grain in one environment. Other creatures, like the crows, aren’t very good at anything in particular, but they’re extremely good at learning laws of different environments.
And of course, we human beings are way out on the end the distribution like the crows. We have bigger brains relative to our bodies far than any other animal. We’re smarter, we’re more flexible, can learn more, we survive in more different environments, we migrated to the world and even go to outer space. And our and children are dependent on us for much longer than babies of any other species. My son is 23. (Laughter) And at least until they’re 23, we’re still popping worms into those little open mouths.
All right, why we see this correlation? Well an idea is that that strategy, learning strategy, is an extremely powerful, great strategy for getting on in the world, but it has big disadvantage. And that one big disadvantage is that, you actually do all that learning, you’re going to helpless. So you don’t want to have the mastodon at you 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 show up. And the way the evolutions seems to solved that problem is with a kind of division labor. So the idea is that we have this period when we’re completely protected. We don’t have to do anything. we have to do is learn. And then as adults, we can take all those that we learned when we were babies and children and actually put them to 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 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 those ideas that we learned when we were children and actually put them use. Another way of thinking about it is instead of thinking of babies and children as being like grownups, we should think about them as being a different stage of the same species — kind of like caterpillars butterflies — except that they’re actually the brilliant butterflies who flitting around the garden and exploring, and we’re the caterpillars who inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to learn — and this evolutionary story would children are for learning, that’s what they’re for — we might that they would have really powerful learning mechanisms. And fact, the baby’s brain seems to be the most powerful learning computer on planet. But real computers are actually getting to be lot better. And there’s been a revolution in our understanding of machine learning recently. it all depends on the ideas of this guy, the Thomas Bayes, who was a statistician and mathematician in the 18th century. And essentially what did was to provide a mathematical way using probability theory to characterize, describe, way that scientists find out about the world. So what 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 test that new hypothesis 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 machine learning programs that we have now. And some 10 years ago, I that babies might be doing the same thing.
So if you to know what’s going on underneath those beautiful brown eyes, I it actually looks something like this. This is Reverend Bayes’s notebook. I think those babies are actually making complicated calculations with conditional probabilities they’re revising to figure out how the world works. All right, now that seem like an even taller order to actually demonstrate. after all, if you ask even grownups about statistics, they look extremely stupid. How it be that children are doing statistics?
So to test this we a machine that we have called the Blicket Detector. is a 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 learning about the world. Let me mention just one we did with Tumar Kushner, my student. If I showed this detector, you would be likely to think to begin with that the way make the detector go would be to put a on top of the detector. But actually, this detector works in a bit of strange way. Because if you wave a block over top of the detector, something you wouldn’t ever think to begin with, the detector will actually activate two out of three times. Whereas, if you do likely thing, put the block on the detector, it will only activate out of six times. So the unlikely hypothesis actually has stronger evidence. looks as if the waving is a more effective than the 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 of the detector.
Now there are two things that are really interesting this. The first one is, again, remember, these are four year-olds. They’re just how to count. But unconsciously, they’re doing these quite complicated calculations that will give them a probability 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 very unlikely to begin with. And in studies we’ve been doing in my lab, similar studies, we’ve show that year-olds are actually better at finding out an unlikely hypothesis adults are when we give them exactly the same task. 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 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 around 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 go and red ones didn’t, and then she showed them an anomaly. And what you’ll is that this little boy will go through five in the space of two minutes.
(Video) Boy: How about this? as the other side.
Alison Gopnik: Okay, so his hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, and this 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 like 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 experimenter to do this, to try putting it out onto the location. Not working either.
Boy: Oh, because the light goes only to here, not here. Oh, the of this box has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s a hypothesis.
Boy: It’s lighting up. So when you put four. you put four on this one to make it light up and two this one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is particularly adorable and articulate little boy, but what Cristine is this is actually quite typical. If you look at the way children play, you ask them to explain something, what they really do is do series of experiments. This is actually pretty 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 butterflies who can test five hypotheses in two minutes? Well, if go back to those psychologists and philosophers, a lot of them have said that babies young children were barely conscious if they were conscious at all. And I think 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. So happens for adults is we decide that something’s relevant or important, should pay attention to it. Our consciousness of that thing that we’re attending to extremely bright and vivid, and everything else sort of goes dark. And even know something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, the of executive part of our brains, sends a signal that makes a little part of 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 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 good at taking in lots information from lots of different sources at once. And if you actually in their brains, you 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 children bad at paying attention, what we really mean is that they’re bad at not attention. So they’re bad at getting rid of all the interesting things that could tell them and just looking at the thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from those butterflies who are designed learn.
Well if we want to think about a way of getting a taste of that of baby consciousness as adults, I think the best thing is think about cases where we’re put in new situation that we’ve never been in before — we fall in love with someone new, or when we’re in a new 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 full of and experience than all the months of being a walking, talking, faculty meeting-attending zombie back home. by the way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics effect of those baby neurotransmitters. So what’s it like be a baby? It’s like being in love in for 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 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 things like tie our shoelaces and cross the street by ourselves. it makes sense that we put a lot of effort into making think like adults do. But if what we want is to be like those butterflies, have open-mindedness, open learning, imagination, creativity, innovation, maybe at some of the time we should be getting the adults to start more like children.
(Applause)