What is going on this baby’s mind? If you’d asked people this 30 ago, most people, including psychologists, would have said that this was irrational, illogical, egocentric — that he couldn’t take the perspective of person or understand cause and effect. In the last 20 years, developmental has completely overturned that picture. So in some ways, we that this baby’s thinking is like the thinking of most brilliant 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 in the mind of that other baby. After all, one of things that’s hardest for all of us to do is to out what other people are thinking and feeling. And maybe the thing of all is to figure out that what other people and feel isn’t actually exactly like what we think and feel. who’s followed politics can testify to how hard that for some people to get. We wanted to know if babies and young children could understand really profound thing about other people. Now the question is: How we ask them? Babies, after all, can’t talk, and 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 ask them the question?
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Well it turns out that the secret was broccoli. What did — Betty Rapacholi, who was one of my students, and I — was actually to give babies two bowls of food: one bowl of raw broccoli one bowl of delicious goldfish crackers. Now all of the babies, even in Berkley, like the crackers don’t like the raw broccoli. (Laughter) But then what Betty did was to take a little taste food from each bowl. And she would act as she liked it or she didn’t. So half the time, acted as 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 go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a little bit of crackers, and she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” she’d act as if what she wanted was just opposite of what the babies wanted. We did this with 15 and 18 month-old babies. then she would simply put her hand out and say, “Can you me some?”
So the question is: What would the baby her, what they liked or what she liked? And the thing was that 18 month-old babies, just barely walking talking, would give her the crackers if she liked crackers, but they would give her the broccoli if she the broccoli. On the other hand, 15 month-olds would stare at her for a long time if acted as if she liked the broccoli, like they couldn’t figure this out. But then after they stared for long time, they would just give her the crackers, what they thought everybody must like. 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 that they should actually do things to help other people get what wanted.
Even more remarkably though, the fact that 15 month-olds didn’t this suggests that these 18 month-olds had learned this deep, profound fact about human nature the three months from when they were 15 months old. So children both know and learn more than we ever would have thought. And this is just one of hundreds and 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 possible for them to learn so in such a short time? I mean, after all, if you at babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to so much time and energy into just keeping them alive. But if we to evolution for an answer to this puzzle of why we so much time taking care of useless babies, it turns out there’s actually 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 that there’s a relationship between how long a childhood a species has and how their brains are compared to their bodies and how smart flexible they are.
And sort of the posterbirds for this idea are the birds up there. On side is a New Caledonian crow. And crows and other corvidae, ravens, rooks and 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 to use a tool get food. On the other hand, we have our friend the domestic chicken. chickens and ducks and geese and turkeys are basically as dumb dumps. So they’re very, very good at pecking for grain, they’re not much good at doing anything else. Well turns out that the babies, the New Caledonian crow babies, fledglings. They depend on their moms to drop worms their little open mouths for as long as two years, which is a long time in the life of a bird. Whereas the are actually mature within a couple of months. So is the reason why the crows end up on the cover of Science and the end up in the soup pot.
There’s something about that long childhood that seems be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, like chicken, seem to be beautifully suited to doing just one thing very well. So they seem 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 at learning about laws of different environments.
And of course, human beings are way out on the end of the distribution like the crows. have bigger brains relative to our bodies by far than any other animal. We’re smarter, we’re flexible, we can learn more, we survive in more different environments, we migrated cover the world and even go to outer space. And our babies and children dependent on us for much longer than the babies any other species. My son is 23. (Laughter) And least until they’re 23, we’re still popping those worms into little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it has one disadvantage. And that one big disadvantage is that, until you do all that learning, you’re going to be helpless. you don’t want to have the mastodon charging at you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” You want to all that before the mastodons actually show up. And the way the seems 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 do anything. All we have to do is learn. And then as adults, we take all those things that we learned when we were babies and children and put them to work to do things out there the 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 sky guys who just have to go out and learn have good ideas, and we’re production and marketing. We have to take all those ideas that learned when we were children and actually put them to use. Another of thinking about it is instead of thinking of babies and children as being defective grownups, we should think about them as being a different developmental stage of the 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 caterpillars who are inching 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 the most learning computer on the planet. But real computers are actually getting to be lot better. And there’s been a revolution in our of machine learning recently. And it all depends on the ideas of this guy, Reverend Thomas Bayes, who was a statistician and mathematician in the 18th century. And essentially Bayes did was to provide a mathematical way using theory to characterize, describe, the way that scientists find out about world. So what scientists do is they have a that they think might be likely to start with. go out and test it against the evidence. The evidence makes change that hypothesis. Then they test that new hypothesis and so on and so forth. And Bayes showed was a mathematical way that you could do that. And that mathematics is at core of the best machine learning programs that we have now. And some 10 years ago, I that babies might be doing the same thing.
So if want to know what’s going on underneath those beautiful eyes, I think it actually looks something like this. This is Reverend Bayes’s notebook. So I those babies are actually making complicated calculations with conditional probabilities they’re revising to figure out how the world works. All right, now might seem like an even taller order to actually demonstrate. after all, if you ask even grownups about statistics, look extremely stupid. How could it be that children doing statistics?
So to test this we used a that we have called the Blicket Detector. This is a box that lights and plays music when you put some things on it and others. And using this very simple machine, my lab and others have done dozens studies showing just how good babies are at learning about world. Let me mention just one that we did with Tumar Kushner, my student. If I you this detector, you would be likely to think to begin that the way to make the detector go would be to a block on top of the detector. But actually, this detector works in a 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 detector actually activate two out of three times. Whereas, if you the likely thing, put the block on the detector, will only activate two out of six times. So the unlikely actually has stronger evidence. It looks as if the waving is a more effective strategy the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just asked to make it go. And sure enough, the four year-olds the evidence to 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 learning 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 evidence to get to an idea, get to a about the world, that seems very unlikely to begin with. in studies we’ve just been doing in my lab, studies, we’ve show that four year-olds are actually better at finding out an unlikely hypothesis than adults 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 do experiments, and we 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 around is really kind of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did was use Blicket Detectors. And what she did was show children that yellow ones made it and 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 as the side.
Alison Gopnik: Okay, so his first hypothesis has just falsified.
(Laughter)
Boy: This one lighted up, and this one nothing.
AG: Okay, he’s his experimental notebook out.
Boy: What’s making 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: this is his next idea. He told the experimenter to this, to try putting it out onto the other location. Not working either.
Boy: Oh, because the goes only to here, not here. Oh, the bottom of this box has electricity 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 put on this one to make it light up and two on one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, but what discovered is this is actually quite typical. If you look the way children play, when you ask them to explain something, what they really do is a series of experiments. This is actually pretty typical of year-olds.
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Well, what’s it like to be this of creature? What’s it like to be one of these brilliant who can test five hypotheses in two minutes? Well, you go back to those psychologists and philosophers, a lot of them have said that babies and young were barely conscious if they were conscious at all. And think just the opposite is true. I think babies children are actually more conscious than we are as adults. Now here’s what know about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens adults is we decide that something’s relevant or important, we should attention to it. Our consciousness of that thing that we’re attending becomes extremely bright and vivid, and everything else sort of goes dark. And we even something about the way the brain does this.
So what happens when we pay attention is the prefrontal cortex, the sort of executive part of our brains, sends signal that makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in all rest of our brains. So we have a very focused, purpose-driven kind attention. If we look at babies and young children, see something very different. I think babies and young children seem to more of a lantern of consciousness than a spotlight consciousness. So babies and young children are very bad narrowing down to just one thing. But they’re very at taking in lots of information from lots of different at once. And if you actually look in their brains, you see that they’re flooded these neurotransmitters that are really good at inducing learning and plasticity, and the parts haven’t come 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 paying attention. So they’re bad at getting rid of the interesting things that could tell them something and just looking at the 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 way of getting a taste of that kind of consciousness as adults, I think the best thing is think cases where we’re put in a new situation that we’ve never been 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 full of consciousness and experience than all months 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 the effect of 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 up crying at three o’clock in the morning.
(Laughter)
Now it’s good be a grownup. I don’t want to say too much how wonderful babies are. It’s good to be a grownup. We can do things like our shoelaces and cross the street by ourselves. And it makes sense that we a lot of effort into making babies think like do. But if what we want is to be like those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of the time we should be the adults to start thinking more like children.
(Applause)