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 or understand cause and effect. In the last 20 years, developmental science has overturned that picture. So in some ways, we think that this baby’s thinking like the thinking of the most brilliant scientists.
Let give you just one example of this. One thing that baby could be thinking about, that could be going in his mind, is trying to figure out what’s going in the mind of that other baby. After all, one 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 to figure out that what other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can to how hard that is for some people to get. wanted to know if babies and young children could this really profound thing about other people. Now the is: How could we ask them? Babies, after all, can’t talk, and if ask a three year-old to tell you what he thinks, you’ll get is a beautiful stream of consciousness monologue about and birthdays and things like that. So how do actually ask them the question?
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Well it turns out that the secret broccoli. What we did — Betty Rapacholi, who was one of my students, and I — was actually give the babies two bowls of food: one bowl of raw broccoli and bowl of delicious goldfish crackers. Now all of the babies, even in Berkley, like crackers and don’t like the raw broccoli. (Laughter) But then what Betty did was to take a little of food from each bowl. And she would act as if she liked 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 any other sane person. But half the time, what she do is take a little bit of the broccoli and go, “Mmmmm, broccoli. I the broccoli. Mmmmm.” And then she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d act as if what she was just the opposite of what the babies wanted. We did with 15 and 18 month-old babies. And then she simply put her hand out and say, “Can you give me some?”
So the question is: What would baby give her, what they liked or what she liked? And the thing was that 18 month-old babies, just barely walking and talking, would give her the crackers if she the crackers, but they would give her the broccoli 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 broccoli, like they couldn’t figure this out. But then they stared for a long time, they would just give the crackers, what they thought everybody must like. So there are two really remarkable things about this. The one is that these little 18 month-old babies have discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they felt that they should do things to help other people get what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds learned this deep, profound fact about human nature in three months from when they were 15 months old. children both know more and learn more than we ever would have thought. And is just one of hundreds and hundreds of studies over the 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 so in such a short time? I mean, after all, if you look at babies superficially, 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 alive. But if we turn to evolution for an answer to this puzzle of we spend so much time taking care of useless babies, it turns that there’s actually an answer. If we look across many, many different species of animals, not just primates, but also including other mammals, birds, even marsupials 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 for this idea are the birds up there. On side is a New Caledonian crow. And crows and corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird the cover of science who’s learned how to use a to get food. On the other hand, we have our the domestic chicken. And chickens and ducks and geese turkeys are basically as dumb as dumps. So they’re very, very good at 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. depend on their moms to drop worms in their little mouths for as long as two years, which is really long time in the life of a bird. Whereas the chickens are mature within a couple of months. So childhood is the reason why the crows end on the cover of Science and the chickens end up 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 for this? Well some animals, like the chicken, seem to be beautifully suited doing just one thing very well. So they seem to be beautifully to pecking grain in one environment. Other creatures, like the crows, aren’t very good doing anything in particular, but they’re extremely good at learning about laws different environments.
And of course, we human beings are way out on the end of the distribution like crows. We have bigger brains relative to our bodies by far than any animal. We’re smarter, we’re more flexible, we can learn more, we survive in more environments, we migrated to cover the world and even to outer space. And our babies and children are dependent on us much longer 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, why would we see this correlation? Well an idea that that strategy, that learning strategy, is an extremely powerful, great strategy for getting in the world, but it has one big disadvantage. And that one big disadvantage is that, until actually do all that learning, you’re going to be helpless. So you don’t want to have the charging at you and be saying to yourself, “A or maybe a spear might work. Which would actually be better?” want to know all that before the mastodons actually show up. And the way the evolutions to have solved that problem is with a kind of division of labor. So the idea is we have this early period when we’re completely protected. We don’t have to do anything. All we have do is learn. And then as adults, we can take all those that we learned when we were babies and children and put them to work to do things out there in world.
So one way of thinking about it is that babies young children are like the research and development division of the human species. So they’re the protected blue guys who just have to go out and learn and have ideas, and we’re production and marketing. We have to all those ideas that we learned when we were and actually put them to use. Another way of about it is instead of thinking of babies and children being like defective grownups, we should think about them as being a different developmental stage of same species — kind of like caterpillars and butterflies — except that they’re actually the brilliant who are flitting around the garden and exploring, and we’re the who are inching along our narrow, grownup, adult path.
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If this is true, if these babies are designed learn — and this evolutionary story would say children for learning, that’s what they’re for — we might expect that they would really powerful learning mechanisms. And in fact, the baby’s brain seems to be most powerful learning computer on the planet. But real computers are actually getting be a lot better. And there’s been a revolution in our of machine learning recently. And it all depends on ideas of this guy, the Reverend Thomas Bayes, who a statistician and mathematician in the 18th century. And essentially Bayes did was to provide a mathematical way using probability theory to characterize, describe, the way scientists find out about the world. So what scientists do is they have a hypothesis that they might be likely to start with. They go out and test it against the evidence. The makes them change that hypothesis. Then they test that hypothesis and so on and so forth. And what Bayes showed a mathematical way that you could do that. And that mathematics is at the core of best machine learning programs that we have now. And 10 years ago, I suggested that babies might be doing same thing.
So if you want to know what’s going on underneath those beautiful brown eyes, think it actually looks something like this. This is Reverend Bayes’s notebook. So think those babies are actually making complicated calculations with conditional that they’re revising to figure out how the world works. All right, now that seem like an even taller order to actually demonstrate. Because after all, if you ask even grownups statistics, they look extremely stupid. How could it be that children are statistics?
So to test this we used a machine that we have called the Blicket Detector. This a box that lights up and plays music when you put things on it and not others. And using this simple machine, my lab and others have done 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 the way to make the detector go would be to a block on top of the detector. But actually, this detector works a bit of a strange way. Because if you wave a block over the top the detector, something you wouldn’t ever think of to begin with, the detector will actually two out of three times. Whereas, if you do the thing, put the block on the detector, it will only two out of six times. So the unlikely hypothesis actually stronger evidence. It looks as if the 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 go. And sure enough, the four year-olds used the evidence to wave the object on of the detector.
Now there are two things that are really interesting about this. The one is, again, remember, these are four year-olds. They’re just how to count. But unconsciously, they’re doing these quite calculations that will give them a conditional probability measure. And the other interesting thing that they’re using that evidence 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 hypothesis than adults are when we give them exactly the task. So in these circumstances, the children are using statistics to find out the world, but after all, scientists also do experiments, and we wanted to see if children are experiments. When children do experiments we call it “getting into everything” else “playing.”
And there’s been a bunch of interesting studies that have shown this playing around is really a kind of experimental program. Here’s one from Cristine Legare’s lab. What Cristine did use our Blicket Detectors. And what she did was show children that yellow ones made it go red ones didn’t, and then she showed them an anomaly. 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 the other 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 notebook 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 to be this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told the to do this, to try putting it out onto the other location. Not working either.
Boy: Oh, because 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 a hypothesis.
Boy: It’s lighting up. So when you put four. you put four on this one to make it light and two on this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and articulate boy, but what Cristine discovered is this is actually quite typical. you look at the way children play, when you ask them explain something, what they really do is do a series of experiments. 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 brilliant butterflies who can five 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 conscious if they were conscious at all. And I think the opposite is true. I think babies and children are more conscious than we are as adults. Now here’s we know about how adult consciousness works. And adults’ and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant important, we should pay attention to it. Our consciousness of thing that we’re attending to becomes extremely bright and vivid, and everything else sort of goes dark. we even know something about the way the brain this.
So what happens when we pay attention is that the prefrontal cortex, the sort 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 of our brains. So we have a very focused, purpose-driven kind of attention. If we at babies and young children, we see something very different. think babies and young children seem to have more of lantern of consciousness than a spotlight of consciousness. So and young children are very bad at narrowing down to just one thing. But they’re very good taking in lots of information from lots of different sources at once. And if you actually look in brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and the inhibitory haven’t come on yet. So when we say that babies young children are bad at paying attention, what we really is that they’re bad at not paying attention. So they’re bad at getting rid of the interesting things that could tell them something and looking at the thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from those butterflies who designed to learn.
Well if we want to think about a way of getting taste of that kind of baby consciousness as adults, I think the thing 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 for the time. And what happens then is not that our contracts, it expands, so that those three days in seem to be more full of consciousness and experience than all the of being a walking, talking, faculty meeting-attending zombie back home. And by the way, coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics the effect those baby neurotransmitters. So what’s it like to be a baby? It’s like in love in Paris for the first time after you’ve had three double-espressos. (Laughter) That’s fantastic way to be, but it does tend to leave you waking up crying at three o’clock in 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. We do 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 be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at some of the time we should be getting the to start thinking more like children.
(Applause)