What is going on in this baby’s mind? If you’d people this 30 years ago, most people, including psychologists, would have said that this was irrational, illogical, egocentric — that he couldn’t take the of another person or understand cause and effect. In the last 20 years, science has completely overturned that picture. So in some ways, we think that this baby’s thinking is like 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 going on in his mind, is trying to figure what’s going on in the mind of that other baby. After all, of the things that’s hardest for all of us to is to figure out what other people are thinking and feeling. And maybe hardest thing of all is to figure out that what other people think and isn’t actually exactly like what we think and feel. who’s followed politics can testify to how hard that is some people to get. We wanted to know if babies young children could understand this really profound thing about other people. Now the is: How could we ask them? Babies, after all, can’t talk, if you ask a three year-old to tell you he thinks, what you’ll get is a beautiful stream of consciousness 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 was broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give the two bowls of food: one bowl of raw broccoli and one bowl delicious goldfish crackers. Now all of the babies, even in Berkley, like crackers and don’t like the raw broccoli. (Laughter) But then what did was to take a little taste of food from each bowl. she would act as if she liked it or she didn’t. So half the time, she acted if she liked the crackers and didn’t like the broccoli — just like a baby and any sane person. But half the time, what she would do is a little bit of the broccoli and 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. tasted the crackers. Eww, yuck.” So 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 give 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 barely walking and talking, would give her the if she liked the crackers, but they would give her the broccoli she liked the broccoli. On the other hand, 15 month-olds would stare at her a long time if she acted as if she liked the broccoli, like they couldn’t figure this out. then after they stared for a long time, they would give her the crackers, what they thought everybody must like. So there are two really remarkable about this. The first one is that these little 18 month-old babies have already discovered really profound fact about human nature, that we don’t always want the same thing. And what’s more, they that they 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 these 18 month-olds had learned this deep, profound fact about human nature in the three months when they were 15 months old. So children both know more learn more than we ever would have thought. And this just one of hundreds and hundreds of studies over the last 20 years that’s actually it.
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The question you might ask though is: do children learn so much? And how is it for them to learn so much in such a time? I mean, after all, if you look at superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, we have to put so much time and energy into just keeping alive. But if we turn to evolution for an answer to this puzzle why we spend so much time taking 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 like kangaroos wombats, it turns out that there’s a relationship between how a childhood a species has and how big their brains are compared to bodies and how smart and flexible they are.
And sort of the posterbirds for this idea are birds up there. On one side is a New Caledonian crow. And and other corvidae, ravens, rooks and so forth, are smart birds. They’re as smart as chimpanzees in some respects. this is a bird on the cover of science who’s how to use a tool to get food. On other hand, we have our friend the domestic chicken. And chickens and ducks and geese and turkeys basically as dumb as dumps. So they’re very, very good pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, 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 time in the life of a bird. Whereas the are actually mature within a couple of months. So childhood is the reason why 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. 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. So they seem be beautifully suited to pecking grain in one environment. Other creatures, 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 of the distribution like the crows. We have bigger brains relative our bodies by far than any other animal. We’re smarter, we’re more flexible, we can learn more, survive in more different environments, we migrated to cover the world and even go to space. And our babies and children are dependent on us for much longer than the babies of other species. My son is 23. (Laughter) And at until they’re 23, we’re still popping those worms into those open mouths.
All right, why would we see this correlation? Well idea is that that strategy, that learning strategy, is an powerful, great 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 be helpless. So you don’t want to have the mastodon charging at you and be to yourself, “A slingshot or maybe a spear might work. Which would be better?” You want to know all that before the mastodons actually show up. the way the evolutions seems to have solved that is with a kind of division of labor. So the is that we 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 can take those things that we learned when we were babies and children actually put them to work to do things out there the world.
So one way of thinking about it is that babies and young children are the research and development division of the human species. 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 those ideas that we learned when we were children and actually put them to use. 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 developmental stage of the same species — kind of like caterpillars and butterflies — except they’re actually the brilliant butterflies who are flitting around the and exploring, and we’re the caterpillars who are inching our narrow, grownup, adult path.
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If this is true, if these babies are designed to — and this evolutionary story would say children are for learning, that’s what they’re — we might expect that they would have really learning mechanisms. And in fact, the baby’s brain seems to be most powerful learning computer on the planet. But real computers actually getting to be a lot better. And there’s been a revolution in our understanding of machine recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician and in the 18th century. And essentially what Bayes did was to provide a mathematical way probability theory to characterize, describe, the way that scientists out about the world. So what scientists do is they a hypothesis that they think might be likely to with. They go out and test it against the evidence. evidence 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. And that mathematics at the core of the best machine learning programs that have now. And some 10 years ago, I suggested that might be doing the same thing.
So if you to know what’s going on underneath those beautiful brown eyes, I think it actually looks something 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 even taller order to actually demonstrate. Because after all, if you ask even grownups about statistics, look extremely stupid. How could it be that children are doing statistics?
So to test this we used machine that we have called the Blicket Detector. This is a that lights up and plays music when you put some on it and not others. And using this very machine, my lab and others have done dozens of studies showing just how good babies are at learning the world. Let me mention just one that we did Tumar Kushner, my student. If I showed you this detector, would be likely to think to begin with that way to make the detector go would be to put a on top of the detector. But actually, this detector works in bit of a strange way. Because if you wave a block over the top of detector, something you wouldn’t ever think of to 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 two of six times. So the unlikely hypothesis actually has stronger evidence. It looks as if the waving a more effective strategy than the other strategy. So we just this; we gave four year-olds this pattern of evidence, and we just asked them to make go. And sure enough, the four year-olds used the evidence wave the object on top of the detector.
Now are two things that are really interesting about this. The 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 will give a conditional probability measure. And the other interesting thing is that they’re using that evidence get to an idea, get to a hypothesis about world, that seems very unlikely to begin with. And in we’ve just been doing in my lab, similar studies, we’ve show four year-olds are actually better at finding out an hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using statistics to find out the world, but after all, scientists also do experiments, and wanted to see if children are doing experiments. When children do experiments we call “getting into everything” or else “playing.”
And there’s been a of interesting studies recently that have shown this playing is really a kind of experimental research program. Here’s one from Cristine Legare’s lab. Cristine did was use our Blicket Detectors. And what she did was show children that ones made it go and red ones didn’t, and she showed them an anomaly. And what you’ll see that this little boy will go through five hypotheses in 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 this light up. (Laughter) I don’t know.
AG: Every scientist will recognize that expression despair.
(Laughter)
Boy: Oh, it’s because this needs to be like this, and this needs 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, to putting it out onto the other location. Not working either.
Boy: Oh, the light goes only to here, not here. Oh, the bottom of 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 you four on this one to make it light up and on this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that is a particularly and articulate little boy, but what Cristine discovered is this is actually typical. If you look at the way children play, when you them to explain something, what they really do is do a series of experiments. This is actually typical of four year-olds.
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Well, what’s it like to be this kind creature? What’s it like to be one of these butterflies who can test five hypotheses in two minutes? Well, you go back to those psychologists and philosophers, a lot of have said that babies and young children were barely 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 know about how adult consciousness works. adults’ attention and consciousness look kind of like a spotlight. So what for adults is we decide that 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 something about the way the brain does this.
So happens when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a signal that a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in all the rest of our brains. So have a very focused, purpose-driven kind of attention. If we look at babies and children, we see something very different. I think babies and children seem to have more of a lantern of consciousness a spotlight of consciousness. So babies and young children are very bad at narrowing down to just thing. But they’re very good at taking in lots of information from of different sources at once. And if you actually look in their brains, you see that they’re with these neurotransmitters that are really good at inducing learning and plasticity, and the inhibitory parts haven’t on yet. So when we say that babies and young children are bad at paying attention, we really mean is that they’re bad at not paying attention. So they’re at getting rid of all the interesting things that tell them something and just looking at the thing that’s important. That’s the of 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 taste of that kind of baby consciousness as adults, think the best thing is think about cases where we’re put in a new that we’ve never been in before — when we fall in love someone new, or when we’re in a new city for the first time. And what happens is not that our consciousness contracts, it expands, so that those three days in Paris seem be more full of consciousness and experience than all months of being a walking, talking, faculty meeting-attending zombie back home. And by 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 Paris for the first time you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it does tend leave you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s to be a grownup. I don’t want to say too about how wonderful babies are. It’s good to be a grownup. can do things like tie our shoelaces and cross the by ourselves. And 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 least of the time we should be getting the adults start thinking more like children.
(Applause)