What is going on this baby’s mind? If you’d asked people this 30 years ago, most people, psychologists, would have said that this baby was irrational, illogical, egocentric — he couldn’t take the perspective of another person or cause and effect. In the last 20 years, developmental has completely overturned that picture. So in some ways, we think that this baby’s thinking like the thinking of the most brilliant scientists.
Let me give you just one example of this. One that this baby could be thinking about, that could be going on his mind, is trying to figure out what’s going on in the mind that other baby. After all, one of the things that’s hardest for all us to do is to figure out what other people are and feeling. And maybe the hardest thing of all is to out that what other people think and feel isn’t actually like what we think and feel. Anyone who’s followed politics testify to how hard that is for some people to get. We wanted to know if babies and children could understand this really profound thing about other people. Now the is: How could we ask 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 things like that. So do we actually ask them the question?
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Well it turns out the secret was broccoli. What we did — Betty Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: bowl of raw broccoli and one bowl of delicious crackers. Now all of the babies, even in Berkley, like the and don’t like the raw broccoli. (Laughter) But then Betty did was to take a little taste of from each bowl. And she would act as if she liked it or she didn’t. half the time, she acted as if she liked the crackers didn’t like the broccoli — just like a baby and any sane person. But half the time, what she would do is take a little bit the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And she would take a little bit of the crackers, and she’d go, “Eww, yuck, crackers. I tasted crackers. Eww, yuck.” So she’d act as if what she wanted just the opposite of what the babies wanted. We did with 15 and 18 month-old babies. And then she would simply put her hand out say, “Can you give me some?”
So the question is: would the baby give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just barely walking and talking, would give her the if she liked the crackers, but they would give her the if she liked the broccoli. On the other hand, 15 month-olds would stare at for a long time if she acted as if she liked the broccoli, they couldn’t figure this out. But then after they stared a long time, they would just give her the crackers, what they thought must like. So there are two really remarkable things 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 should actually do things to help other people get what wanted.
Even more 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 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 do learn so much? And how is it possible for them to learn much in 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 into just keeping them alive. But we turn to evolution for an answer to this puzzle of why we so much time taking care of useless babies, it turns out that there’s an answer. If we look across many, many different species of animals, not just us primates, also including other mammals, birds, even marsupials 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 smart and flexible they are.
And sort the posterbirds for this idea 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 respects. And this is a bird on the cover of science who’s learned how use a tool to get food. On the other hand, we have our friend the domestic chicken. And and ducks and geese and turkeys are basically as dumb 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. They depend their moms to drop worms in their little open mouths as long as two years, which is a really long in the life of a bird. Whereas the chickens actually mature within a couple of months. So childhood is the reason why the end up on the cover of Science and the chickens end up in the pot.
There’s something about that long childhood that seems to connected to knowledge and learning. Well what kind of explanation 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 be beautifully suited to pecking grain in environment. Other creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about laws of environments.
And of course, we human beings are way on the end of the distribution like the crows. We have bigger brains to our bodies by far than any other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to the world and even go to outer space. And babies and children are dependent on us for much than the babies of any other species. My son 23. (Laughter) And at least until they’re 23, we’re popping those worms into those little open mouths.
All right, would 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, it has one big disadvantage. And that one big 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 maybe spear might work. Which would actually be better?” You want know all that before the mastodons actually show up. the way the evolutions seems to have solved that problem is with a kind of 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 do is learn. And then as adults, we can all those things that we learned when we were babies and children and actually them to work to do things out there in the world.
So one of thinking about it is that babies and young children are the research and development division of the human species. So they’re the protected blue sky who just have to go out and learn and have good ideas, and we’re production marketing. We have to take all those ideas that we learned when we were children and actually them to use. Another way of thinking about it is of thinking of babies and children as being like defective grownups, we should think them as being a different developmental stage of the same species — of like caterpillars and butterflies — except that they’re actually the brilliant butterflies who are flitting the garden and exploring, and we’re the caterpillars who inching along our narrow, grownup, adult path.
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If this true, if these babies are designed to learn — this evolutionary story would say children are for learning, that’s they’re for — we might expect that they would have really powerful learning mechanisms. And fact, the baby’s brain seems to be the most powerful computer on the planet. But real computers are actually to be a lot better. And there’s been a revolution in understanding of machine learning recently. And it all depends on the ideas of this guy, the Reverend Bayes, who was a statistician and mathematician in the 18th century. And essentially what Bayes did was to provide a way using probability theory to characterize, describe, the way that scientists find about the world. So what scientists do is they have a hypothesis that they think might likely to start with. They go out and test it against the evidence. The makes them change that hypothesis. Then they test that new hypothesis and so on and so forth. what Bayes showed was a mathematical way that you could do that. that mathematics is at the core of the best machine learning programs that we have now. some 10 years ago, I suggested that babies might be doing the same thing.
So if you want know what’s going on underneath those beautiful brown eyes, think it actually looks something like this. This is Bayes’s notebook. So I think those babies are actually making calculations with conditional probabilities that they’re revising to figure out how world works. All right, now that might seem like an even taller order actually demonstrate. Because after all, if you ask even about statistics, they look extremely stupid. How could it that children are doing statistics?
So to test this we used a machine that we called the Blicket Detector. This is a box that lights up and plays music when you put some on it and not others. And using this very simple machine, my lab and others done dozens of studies showing just how good babies are learning about the world. Let me mention just one that we with Tumar 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 top the detector. But actually, this detector works in a bit of a way. Because if you wave a block over the 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 do the likely thing, put the block on the detector, it only activate two out of six times. So the unlikely actually has stronger evidence. It looks as if the waving is a effective strategy than the other strategy. So we did this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And sure enough, the four year-olds 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 year-olds. They’re just learning how to count. But unconsciously, they’re these quite complicated calculations that will give them a probability measure. And the other interesting thing is that they’re using that to get to an idea, get to a hypothesis the world, that seems very unlikely to begin with. And in 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 are when we give them exactly the same task. So in these circumstances, the children using statistics to find out about the world, but after all, scientists also do experiments, and we to see if children are doing experiments. When children do we call it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown this playing is really a kind of experimental research program. Here’s from Cristine Legare’s lab. What Cristine did was use our Detectors. And what she did was show children that yellow ones it go and red ones didn’t, and then she 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: about this? Same as the other side.
Alison Gopnik: Okay, so his first hypothesis has just falsified.
(Laughter)
Boy: This one lighted up, and this nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s this light up. (Laughter) I don’t know.
AG: Every scientist will that expression of despair.
(Laughter)
Boy: Oh, it’s because needs to be like this, and this needs to like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He the experimenter to do this, to try putting it out onto other location. Not working either.
Boy: Oh, because the light goes to here, not here. Oh, the bottom of this box has electricity in here, but this doesn’t electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s up. So when you put four. So you put four on this one to make light up and two on this one to make it up.
AG: Okay,there’s his fifth hypothesis.
Now that is a — that is a 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 to 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 back those psychologists and philosophers, a lot of them have said that 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 more conscious we are as 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 that something’s 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 something the way the brain does this.
So what happens when 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, at learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven of attention. If we look at babies and young children, see something very different. I think babies and young seem to have more of a lantern of consciousness than spotlight of consciousness. So babies and young children are very bad at 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 in their brains, you see that they’re flooded with these neurotransmitters that really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say that babies and young children are bad at attention, what we really mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting things that could tell something and just 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 way of getting a taste of that of baby consciousness as adults, I think the best thing is about cases where we’re put in a new situation that we’ve never in before — when we fall in love with someone new, or when we’re a new city for the first time. And what then is not that our consciousness contracts, it expands, so 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, wonderful coffee you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it to be a baby? It’s like being in love in Paris for the time after you’ve had three double-espressos. (Laughter) That’s a way to be, but it does tend to leave waking up crying at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say much about how wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street by ourselves. And it makes that we put a lot of effort into making babies think like do. But if what we want is to be those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults to thinking more like children.
(Applause)