What is going on in baby’s mind? If you’d asked people this 30 years ago, people, including psychologists, would have said that this baby irrational, illogical, egocentric — that he couldn’t take the perspective of another person or understand cause and effect. the last 20 years, developmental science has completely overturned that picture. in some ways, we think that this baby’s thinking is like thinking of the most brilliant scientists.
Let me give just one example of this. One thing that this baby could thinking about, that could be going on in his mind, is trying figure out what’s going on in the mind of that other baby. After all, one of the that’s hardest for all of us to do is to figure out what 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 we think and feel. Anyone who’s followed politics can testify to how hard that is for some to get. We wanted to know if babies and young children understand this really profound thing about other people. Now question 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 monologue about and birthdays and things like that. So how do we actually ask them the question?
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it turns out that the secret was broccoli. What did — Betty Rapacholi, who was one of my students, and I — was actually to give the two bowls of food: one bowl of raw broccoli and one bowl of delicious goldfish crackers. Now all the babies, even in Berkley, like the crackers and don’t the raw broccoli. (Laughter) But then what Betty did was take a little taste of food from each bowl. she would act as if she liked it or didn’t. So half the time, she acted as if liked the crackers and didn’t like the broccoli — just like a baby and other sane person. But half the time, what she would do take a little bit of the broccoli and go, “Mmmmm, broccoli. I the broccoli. Mmmmm.” And then she would take a bit of the crackers, and she’d go, “Eww, yuck, crackers. tasted the crackers. Eww, yuck.” So she’d act as what she wanted was just the opposite of what the wanted. We did this with 15 and 18 month-old babies. And she would simply put her hand out and say, “Can you give some?”
So the question is: What would the baby give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just barely walking talking, would give her the crackers if she liked the crackers, but they give her the broccoli if she liked the broccoli. On other hand, 15 month-olds would stare at her for long time if she acted as if she liked the broccoli, they couldn’t figure this out. But then after they stared for a long time, 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 already discovered this really profound fact about human nature, that we don’t always want same thing. And what’s more, they felt that they should do things to help other people get what they wanted.
Even more 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 months from when were 15 months old. So children both know more and learn more we ever would have thought. And this is just one of and hundreds of studies over the last 20 years that’s demonstrated it.
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The question you might ask though is: Why do learn so much? And how is it possible for to learn so much in such a short time? I mean, after all, if look at babies superficially, they seem pretty useless. And in many ways, they’re worse than useless, because we to put so much time and energy into just keeping them alive. But we turn to evolution for an answer to this puzzle why we spend so much time taking care of babies, it turns out that there’s actually an answer. If look across many, many different species of animals, not us primates, but also including other mammals, birds, even 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 the birds up there. On one side is a New crow. And crows and other corvidae, ravens, rooks and 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 how to use a to get food. On the other hand, we have our friend the domestic chicken. chickens and ducks and geese and turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much good at doing anything else. Well turns out that the babies, the New Caledonian crow babies, are fledglings. They depend on moms to drop worms in their little open mouths for as long as two years, which is a long time in the life of a bird. Whereas the chickens are actually mature within a of months. So childhood is the reason why the crows end up the cover of Science and the chickens end up in the pot.
There’s something about that long childhood that seems be connected to knowledge and learning. Well what kind of explanation could have for this? Well some animals, like the chicken, seem to be beautifully to doing just one thing very well. So they to be beautifully suited to pecking grain in one environment. Other creatures, like crows, aren’t very good at doing anything in particular, but they’re extremely good learning about laws of different environments.
And of course, we human beings are way out on the 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 learn more, we in more different environments, we migrated to cover the world and even go to outer space. our babies and children are dependent on us for much longer than the babies 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 would we see this correlation? Well idea is that that strategy, that learning strategy, is an extremely powerful, great strategy for getting on the world, but it has one big disadvantage. And one big disadvantage is that, until you actually do all that learning, you’re going to be helpless. 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 actually be better?” You to know all that before the mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind 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 and children and actually put them to work to do out there in the world.
So one way of thinking about is that babies and young children are like the and development division of the human species. So they’re the protected blue guys who just have to go out and learn and have good ideas, we’re production and marketing. We have to take all those ideas that learned when we were children and actually put them use. Another way of thinking about it is instead of of babies and children as being like defective grownups, should think about them as being a different developmental stage of the same species — of like caterpillars and butterflies — except that they’re actually the butterflies 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 these babies designed to learn — and this evolutionary story would say children 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 the planet. But real computers are getting to be a 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 Reverend Thomas Bayes, who a statistician and mathematician in the 18th century. And essentially what Bayes did was provide a mathematical 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 might be likely to start with. They go out test it against the evidence. The evidence makes them change that hypothesis. Then they test that new and so on and so forth. And what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of best machine learning programs that we have now. And some 10 years ago, I suggested that might be doing the same thing.
So if you want 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 babies are making complicated calculations with conditional probabilities that they’re revising to figure how the world works. All right, now that might seem like an even order to actually demonstrate. Because after all, if you ask even grownups about statistics, they look extremely stupid. could it be that children are doing statistics?
So test this we used a machine that we have called the Blicket Detector. This a box that lights up and plays music when put some things on it and not others. And using 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 we did with Tumar Kushner, my student. If I showed you this detector, you would likely to think to begin with that the way to the detector go would be to put a block top of the detector. But actually, this detector works a bit of a strange way. Because if you wave a block the top of the detector, something you wouldn’t ever think of to begin with, the will actually activate two out of three times. Whereas, you do the likely thing, put the block on detector, it will only activate two out of six times. So the unlikely hypothesis has stronger evidence. It looks as if the waving is a effective strategy than the other strategy. So we did just this; gave four year-olds this pattern 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 four 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 about the world, that seems very to begin with. And in studies we’ve just been doing in my lab, similar studies, we’ve show that year-olds are actually better at finding out an unlikely than 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 after all, also do experiments, and we wanted to see if children are 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 this around is really a kind of experimental research program. Here’s one from Legare’s lab. What Cristine did was use our Blicket Detectors. And she did was show children that yellow ones made go and red ones didn’t, and then she showed them 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 other side.
Alison Gopnik: Okay, so first hypothesis has just been falsified.
(Laughter)
Boy: This one up, and this one nothing.
AG: Okay, he’s got his experimental out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: scientist 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 his next idea. told the experimenter to do this, to try putting it out the other location. Not working either.
Boy: Oh, because light goes only to here, not here. Oh, the bottom of this box has electricity in here, but doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So you put four. So you put four on this one make it light up and two on this one make it light up.
AG: Okay,there’s his fifth 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 the way children play, when you ask them to explain something, they really do is do a series of experiments. This actually pretty typical of 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 can test hypotheses in two minutes? Well, if you go back to those psychologists and philosophers, lot 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. Now here’s we know about how adult consciousness works. And adults’ attention and consciousness look kind of a spotlight. So what happens for adults is we decide that something’s relevant or important, we should attention to it. Our consciousness of that thing that we’re attending to becomes extremely bright and vivid, everything 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 executive of our brains, sends a signal that makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in the rest of our brains. So we have a focused, purpose-driven kind of attention. If we look at and young children, we see something very different. I think and young children seem to have more of a lantern of consciousness than spotlight of consciousness. So babies and young children are very at narrowing down to just one thing. But they’re very at taking in lots of information from lots of different sources at once. And if you actually in their brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and the inhibitory parts haven’t come on yet. when we say that babies and young children are bad at attention, what we really mean is that they’re bad not paying attention. So 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 a taste of that kind of baby consciousness as adults, I think the best is think about cases where we’re put in a new situation that we’ve been in before — when we fall in love someone new, or when we’re in a new city the first time. And what happens then is not that our consciousness contracts, it expands, so that three days in Paris seem to be more full of consciousness and experience than the months of being a walking, talking, faculty meeting-attending back home. And by the way, that coffee, that wonderful you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. what’s it like to be a baby? It’s like being love in Paris for the first time after you’ve had double-espressos. (Laughter) That’s a fantastic way to be, but does tend to leave you waking up crying at o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want to say much about how wonderful babies are. It’s good to be a grownup. can do things like tie our shoelaces and cross street by ourselves. And it makes sense that we a lot of effort into making babies think like adults do. But what we want is to be like those butterflies, to have open-mindedness, learning, imagination, creativity, innovation, maybe at least some of the time we should be getting adults to start thinking more like children.
(Applause)