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 perspective of another person understand cause and effect. In the last 20 years, developmental has completely overturned that picture. So in some ways, we think this baby’s thinking is like the thinking of the most brilliant scientists.
Let give you just one example of this. One thing that this baby could be thinking about, that be going on in his mind, is trying to out what’s going on in the mind of that other baby. After all, one the things that’s hardest for all of us to is to figure out what other people are thinking and feeling. maybe the hardest thing of all is to figure 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 to know if babies and young children could understand this really profound thing other people. Now the question is: How could we them? Babies, after all, can’t talk, and if you ask a three year-old to tell what he thinks, what you’ll get is a beautiful stream of monologue about ponies and birthdays and things like that. So how do actually ask them the question?
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Well it out that the secret was broccoli. What we did — Betty Rapacholi, was one of my students, and I — was actually to give the babies bowls of food: one bowl of raw broccoli and one bowl of goldfish crackers. Now all of the babies, even in Berkley, the crackers and don’t like the raw broccoli. (Laughter) But then what did was to take a little taste of food from each bowl. And she would act if she liked it or she didn’t. So half the time, she acted as if liked the crackers and didn’t like the broccoli — just like baby and any other sane person. But half the time, what she would do is take a little of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And 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 wanted was the 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 give 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 and talking, would give the crackers if she liked the 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 after they stared for a long time, they would just give the crackers, what they thought everybody must like. So there two really remarkable things about this. The first one that these little 18 month-old babies have already discovered this really profound fact about nature, that we don’t always want the same thing. what’s more, they felt that they should actually do things to other people get what they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t do suggests that these 18 month-olds had learned this deep, profound fact about nature in the three months from when they were 15 months old. So both know more and 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 demonstrated it.
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The question you might ask though is: Why do children learn much? And how is it possible for them to learn so much in such short time? I mean, after all, if you look at babies superficially, they seem pretty useless. actually in many ways, they’re worse than useless, because we have to put so much time energy into just keeping them alive. But if we turn to evolution for answer to this puzzle of why we spend so much time taking care useless babies, it turns out that there’s actually an answer. we look across many, many different species of animals, not just primates, but also including other mammals, birds, even marsupials like and wombats, it turns out that there’s a relationship between how a childhood a species has and how big their brains are to their bodies and how smart and flexible they are.
And sort the posterbirds for this idea are the birds up there. one side is a New Caledonian crow. And crows other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as as chimpanzees in some respects. And this is a bird on cover of science who’s learned how to use a tool get food. On the other hand, we have our friend domestic chicken. And chickens and ducks and geese and turkeys basically as dumb as dumps. So they’re very, very at pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, the New Caledonian crow babies, fledglings. They depend on their moms to drop worms in their little mouths for as long as two years, which is a really long time the life of a bird. Whereas the chickens are actually mature within a couple of months. So is the reason why the crows end up on the cover of Science the chickens end up in the soup pot.
There’s something about that long childhood seems 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 to doing one thing very well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t 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 like the crows. We have bigger brains relative to our bodies by than any other animal. We’re smarter, we’re more flexible, can learn more, we survive in more different environments, 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 least they’re 23, we’re still popping those worms into those open mouths.
All right, why would we see this correlation? an idea is that that strategy, that learning strategy, an extremely powerful, great strategy for getting on in world, but it has one big disadvantage. And that one big disadvantage 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 to know all before the mastodons actually show up. And the way the seems to have solved that problem is with a kind of division labor. So the idea is that we have this period when we’re completely protected. We don’t have to do anything. All have to do is learn. And then as adults, we can take all things that we learned when we were babies and children and actually put them work to do things out there in the world.
So one way of about it is that babies and young children are like the research and development of the human species. So they’re the protected blue sky guys who just have to go out and and have good ideas, and we’re production and marketing. We have to take all those ideas that we when we were children and actually put 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 — kind of like caterpillars butterflies — except that they’re actually the brilliant butterflies who are flitting around garden and exploring, and we’re the caterpillars who are along our narrow, grownup, adult path.
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If this true, if these babies are designed to learn — and evolutionary story would say children are for learning, that’s what they’re for — might expect that they would have really powerful learning mechanisms. And in fact, baby’s brain seems to be the most powerful learning 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 ideas of this guy, the Reverend Thomas Bayes, who was statistician and mathematician in the 18th century. And essentially what Bayes did was to provide a mathematical using probability theory to characterize, describe, the way that scientists find out the 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 them change hypothesis. Then they test that new hypothesis and so and so forth. And what Bayes showed was a way that you could do that. And that mathematics is at the core of the best machine learning that we have now. And some 10 years ago, I suggested babies might be doing the same thing.
So if you want to know what’s on underneath those beautiful brown eyes, I think it actually looks like this. This is Reverend Bayes’s notebook. So I think those babies are actually complicated 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 to actually demonstrate. after all, if you ask even grownups about statistics, look extremely stupid. How could it be that children are statistics?
So to test this we used a machine we have called the Blicket Detector. This is a box that lights up and plays music when put some things on it and not others. And using this very simple machine, lab and others have done dozens of studies showing just good babies are at learning about the world. Let me mention just one we did with Tumar Kushner, my student. If I you this detector, you would be likely to think begin with that the way to make the detector would be to put a block on top of the detector. But actually, this works in a bit of a strange way. Because if you wave a over the top of the detector, something you wouldn’t ever think of begin with, the detector will actually activate two out of times. Whereas, if you do the likely thing, put the block the detector, it will only activate two out of six times. So unlikely hypothesis actually has stronger evidence. It looks as if the waving is a more strategy than the other strategy. So we did just this; we gave four year-olds this pattern evidence, and we just asked them to make it go. And sure enough, the four year-olds used evidence to wave the object on top of the detector.
Now there are two things are really interesting about this. The first one is, again, remember, these are year-olds. They’re just learning how to count. But unconsciously, they’re doing these quite complicated calculations that will them a conditional probability measure. And the other interesting thing that they’re using that evidence to get to an idea, to a hypothesis about the world, that seems very to begin with. And in studies we’ve just been doing my lab, similar studies, we’ve show that four year-olds are better at finding out an unlikely hypothesis than adults are we give them exactly the same task. So in these circumstances, the children are using to find out about the world, but after all, also do experiments, and we wanted to see if are doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of interesting studies recently have shown this playing around is really a kind of research program. Here’s one from Cristine Legare’s lab. What did was use our Blicket Detectors. And what she did was show children yellow ones made it go and red ones didn’t, then she showed them an anomaly. And what you’ll is that this little boy will go through five hypotheses in the space of two minutes.
(Video) Boy: about this? Same as the other side.
Alison Gopnik: Okay, so first hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this up. (Laughter) I don’t know.
AG: Every scientist will that expression of despair.
(Laughter)
Boy: Oh, it’s because this to be like this, and this needs to be this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this his next idea. He told the experimenter to do this, try putting it out onto the other location. Not either.
Boy: Oh, because 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 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 particularly — that is a particularly adorable and articulate little boy, but what Cristine discovered this is actually quite typical. If you look at way children play, when you ask them to explain something, what they really do is do series of experiments. This is actually pretty typical of 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 butterflies who can test five hypotheses in two minutes? Well, if you go back to those psychologists philosophers, a lot of them have said that babies and young children were barely if they 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 what we know about adult consciousness works. And adults’ attention and consciousness look kind like a spotlight. So what happens for adults is decide that something’s relevant or important, we should pay attention it. Our consciousness of that 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 executive of our brains, sends a signal that makes a little of our brain much more flexible, more plastic, better at learning, shuts down activity in all the rest of our brains. So we have a very focused, purpose-driven kind attention. If we look at babies and young children, we see something very different. I think and young children seem to have more of a lantern of consciousness than a of consciousness. So babies and young children are very bad narrowing down to just one thing. But they’re very good at in lots of information from lots of different sources at once. And if you actually look their brains, you see that they’re flooded with these that are really good at inducing learning and plasticity, and the inhibitory haven’t come on yet. So when we say that babies and young children are bad paying attention, what we really mean is that they’re bad not paying attention. So they’re bad at getting rid of all interesting things that could tell them something and just at the thing that’s important. That’s the kind of attention, the kind of consciousness, 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, I think the best thing is about cases where we’re put in a new situation 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 in Paris seem to be more full of consciousness and experience than the 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 the effect of those baby neurotransmitters. So what’s it like be a baby? It’s like being in love in Paris 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 three o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want say too much about how wonderful babies are. It’s good to be a grownup. can do things like tie our shoelaces and cross the street by ourselves. And makes sense that we put a lot of effort into making babies think like do. But if what we want is to be like butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe least some of the time we should be getting the adults start thinking more like children.
(Applause)