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 baby was irrational, illogical, egocentric — that couldn’t take the perspective of another person or understand cause and effect. the last 20 years, developmental science has completely overturned that picture. So some ways, we think that this baby’s thinking is the thinking of the most brilliant scientists.
Let me you just one example of this. One thing that this baby be thinking about, that could be going on in his mind, is to figure out what’s going on in the mind of other baby. After all, one of the things that’s hardest all of us to do is to figure out what other people thinking and feeling. And maybe the hardest thing of all is to figure out what other people think and feel isn’t actually exactly like what think and feel. Anyone who’s followed politics can testify to how that is 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 could ask them? Babies, after all, can’t talk, and if you ask a three year-old tell you what he thinks, what you’ll get is a stream of consciousness monologue 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 secret broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give babies two bowls of food: one bowl of raw broccoli and one bowl 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 take a little taste of food from each bowl. And she would act as if liked it or she didn’t. So half the time, acted as if she liked the crackers and didn’t like the — just like a baby and any other sane person. But the time, what she would do is take a bit of the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then would take a little bit of the crackers, and she’d go, “Eww, yuck, crackers. I the crackers. Eww, yuck.” So she’d act as if what she wanted just the opposite of what the babies wanted. We did this 15 and 18 month-old babies. And then she would simply put hand out and say, “Can you give me some?”
So the question is: What the baby give her, what they liked or what she liked? And remarkable thing was that 18 month-old babies, just barely walking and talking, would 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 a long time if she acted if she liked the broccoli, like they couldn’t figure this out. But then they stared for a long time, they would just give her crackers, what they thought everybody must like. So there are two really remarkable things about this. The first is that these little 18 month-old babies have already this really profound fact about human nature, that we don’t always want the thing. And what’s more, they felt that they should actually things to help other people get what they wanted.
Even more remarkably though, the fact that 15 month-olds didn’t this suggests that these 18 month-olds had learned this deep, fact about human nature in the three months from when were 15 months old. So children both know more and more than we ever would have thought. And this is just one of hundreds and hundreds of studies the last 20 years that’s actually demonstrated it.
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The question you might though is: Why do children learn so much? And how is it possible for them to learn much in such a short time? I mean, after all, if you look babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to put so much time and energy into just keeping alive. But if we turn to evolution for an answer to this of why we spend so much time taking care of useless babies, it turns out that there’s actually answer. If we look across many, many different species of animals, just us primates, but also including other mammals, birds, marsupials like kangaroos and wombats, it turns out that there’s a relationship between how long a childhood species has and how big their brains are compared to their bodies and smart and flexible they are.
And sort of the posterbirds for this idea are the up there. On one side is a New Caledonian crow. crows and other corvidae, ravens, rooks and so forth, are incredibly birds. They’re as smart as chimpanzees in some respects. And this 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. And chickens ducks and geese and turkeys are basically as dumb as dumps. they’re very, very good at pecking for grain, and they’re much good at doing anything else. Well it turns that the babies, the New Caledonian crow babies, are fledglings. They depend on their moms drop worms in their little open mouths for as long as years, which is a really long time in the of a bird. Whereas the chickens are actually mature 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 childhood that seems to connected to knowledge and learning. Well what kind of explanation we have for this? Well some animals, like the chicken, seem to be beautifully to doing just one thing very well. So they seem to beautifully suited to pecking grain in one environment. Other creatures, the 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 beings are way out on the end 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, survive in more different environments, we migrated to cover world and even go to outer space. And our babies children are dependent on us for much longer than the babies of any 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? Well an idea that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it one big disadvantage. And that one big disadvantage is that, until you actually do that learning, you’re going to be helpless. So you don’t to have the mastodon charging at you and be saying yourself, “A slingshot or maybe a spear might work. would actually be better?” You want to know all that 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 that we have this early period when we’re completely protected. don’t have to do anything. All we have to 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 the world.
So one way of thinking about it is that babies and young children like 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 to take all those ideas that we learned when we children and actually put them to use. Another way of 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 same species — of like caterpillars and butterflies — except that they’re actually the brilliant butterflies who are flitting around garden and exploring, and we’re the caterpillars who are inching along our narrow, grownup, path.
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If this is true, if these babies are designed learn — and this evolutionary story would say children are for learning, that’s they’re for — we might expect that they would really powerful learning mechanisms. And in fact, the baby’s brain seems to be the powerful learning computer on the planet. But real computers are getting to be a lot better. And there’s been revolution in our understanding 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 what did was to provide a mathematical way using probability to characterize, describe, the way that scientists find out about the world. what scientists do is they have a hypothesis that think might be likely to start with. They go out test it against the evidence. The evidence makes them change hypothesis. Then they test that new hypothesis and so on and forth. And what Bayes showed was a mathematical way that could do that. And that mathematics is at the core of best machine learning programs that we have now. And some 10 ago, I suggested that babies might be doing the thing.
So if you want to know what’s going underneath those beautiful brown eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies are actually complicated calculations with conditional probabilities that they’re revising to figure how the world works. All right, now that might seem like even taller order to actually demonstrate. Because after all, if you ask grownups about statistics, they 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 up and music when you put some things on it and not others. And this very simple machine, my lab and others have dozens of studies showing just how good babies are at about the 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 begin with that the way to make the detector go be to put a block on top of the detector. But actually, this detector in a bit of a strange way. Because if wave a block over the top of the detector, you wouldn’t ever think of to begin with, the detector will actually activate two of three times. Whereas, if you do the likely thing, put block on the detector, it will only activate two out of six times. So the hypothesis actually has stronger evidence. It looks as if the waving is more effective strategy than the other strategy. So we did just this; we four year-olds this pattern of evidence, and we just 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 that really interesting about this. The first one is, again, remember, are four year-olds. They’re just learning how to count. unconsciously, they’re doing these quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re using evidence to get to an idea, get to a hypothesis about the world, that seems very unlikely to with. And 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 these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. When children do experiments call it “getting into everything” or else “playing.”
And there’s a bunch of interesting studies recently that have shown playing 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 what did was show children that yellow ones made it go and red ones didn’t, and then she them an anomaly. And what you’ll see is that this little boy go 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 been falsified.
(Laughter)
Boy: This lighted up, and this one nothing.
AG: Okay, he’s got 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: Now this is his next idea. He told experimenter to do this, to try putting it out onto the other location. Not either.
Boy: Oh, because the light goes only to here, not here. Oh, the of this 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 four. So you put four on this one to make it up and two on this one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is a particularly and articulate little boy, but what Cristine discovered is is actually quite typical. If you look at the way children play, when you them to explain something, what they really do is do a series experiments. This is actually pretty typical of four year-olds.
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Well, what’s it like to this kind of creature? What’s it like to be of these brilliant butterflies who can test five hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have that babies and young children were barely conscious if were conscious at all. And I think just the opposite is true. I babies and children are actually more conscious than we are adults. Now here’s what we know about how adult works. And adults’ attention and consciousness look kind of like a spotlight. what happens for adults is we decide that something’s relevant or important, we pay 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 know about the way the brain does this.
So what happens when we pay attention is that the cortex, the sort of executive part of our brains, sends a signal that makes a little part of brain much more flexible, more plastic, better at learning, and shuts down in all the rest of our brains. So we have very focused, purpose-driven kind of attention. If we look babies and young children, we see something very different. think babies and young children seem to have more a lantern of consciousness than a spotlight of consciousness. babies and young children are very bad at narrowing down to just one thing. 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 they’re flooded with these neurotransmitters that are really good at learning and plasticity, and the inhibitory parts haven’t come on yet. So when we say babies and young children are bad at paying attention, what really mean is that they’re bad at not paying attention. So they’re bad at getting rid all the interesting things that could tell them something 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 to learn.
Well if we want to think about a way getting a taste of that kind of baby consciousness as adults, I the best thing is think about cases where we’re put in new situation that we’ve never been in before — when we fall love with someone new, or when we’re in a new city the first time. And what happens then is not our consciousness contracts, it expands, so that those three days in seem to be more full of consciousness and experience than all the months of 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 being love in Paris for the first time after you’ve three double-espressos. (Laughter) That’s a fantastic way to be, but it does tend to you waking up crying at three o’clock in the morning.
(Laughter)
Now it’s good to be a grownup. don’t want to say too much about how wonderful babies are. It’s good to a grownup. We can do things like tie our shoelaces and cross street by ourselves. And it makes sense that we put a lot of effort into making babies like adults do. But if what we want is to like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be the adults to start thinking more like children.
(Applause)