What going on in this baby’s mind? If you’d asked this 30 years ago, most people, including psychologists, would have said this baby was irrational, illogical, egocentric — that he couldn’t the perspective of another person or understand cause and effect. the last 20 years, developmental science has completely overturned that picture. So in ways, we think 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 going in his mind, is trying to figure out what’s going on in mind of that other baby. After all, one of the things that’s for all of us to do is to figure out what other 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 what we and feel. Anyone who’s followed politics can testify to how hard that is for some people get. We wanted to know if babies and young children understand this 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 what he thinks, what you’ll get is a beautiful stream consciousness monologue about ponies and birthdays and things like that. how do we actually ask them the question?
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Well it turns out that the was broccoli. What we did — Betty Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: bowl of raw broccoli and one bowl of delicious goldfish crackers. Now all of babies, even in Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But then what Betty was to take a little taste of food from each bowl. And she would act as she liked it or she didn’t. So half the time, she acted as if she liked the crackers didn’t like the broccoli — just like a baby any other sane person. But half the time, what she would is take a little bit of the broccoli and go, “Mmmmm, broccoli. I tasted broccoli. Mmmmm.” And then she would take a little bit the crackers, and she’d go, “Eww, yuck, crackers. I tasted crackers. Eww, yuck.” So she’d act as if what she wanted was just the opposite of the babies wanted. We did this with 15 and 18 month-old babies. And then she would simply put her hand and say, “Can you give me some?”
So the question is: What would the baby give her, they liked or what she liked? And the remarkable thing that 18 month-old babies, just barely walking and talking, would give her crackers if she liked the crackers, but they would give her the if she liked the broccoli. On the other hand, 15 month-olds would at her for a long time if she acted as she liked the broccoli, like they couldn’t figure this out. But after they stared for a long time, they would just her the crackers, what they thought everybody must like. So are two really remarkable things about this. The first one is these little 18 month-old babies have already discovered this really profound fact human nature, that we don’t always want the same thing. what’s more, they felt that they should actually do to help other people get what they wanted.
Even remarkably though, the fact that 15 month-olds didn’t do suggests that these 18 month-olds had learned this deep, profound fact about human nature in the months from when they were 15 months old. So children both know more and 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 learn so much? And how is it possible for them to learn much 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 put so much time and into just keeping them alive. But if we turn to evolution for an to this puzzle of why we spend so much time taking care useless babies, it turns out that there’s actually an answer. If we look across many, different species of animals, not just us primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a relationship between how long a 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 and corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart as chimpanzees some respects. And this is a bird on the cover of science who’s learned how to use tool to get food. On the other hand, we our friend the domestic chicken. And chickens and ducks and and turkeys are basically as dumb as dumps. So they’re very, very good 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. depend on their moms to drop worms in their open mouths for as long as two years, which a really long time in the life of a bird. Whereas the chickens actually 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 in soup 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 beautifully suited to doing just one thing very well. So they seem be beautifully suited to pecking grain in one environment. creatures, like the crows, aren’t very good at doing anything in particular, but they’re extremely good at learning laws of different environments.
And of course, we human are way out on the end of the distribution like crows. We have bigger brains relative to our bodies by than any other animal. We’re smarter, we’re more flexible, we can learn more, we survive in different 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 is 23. (Laughter) And at 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, an extremely powerful, great strategy for getting on in the world, 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 don’t want to have the mastodon charging at you and saying to yourself, “A slingshot or maybe a spear might work. Which would actually better?” You want to know all that before the actually show up. And the way the evolutions seems to have solved problem is with a kind of division of labor. So the idea that we have this early period when we’re completely protected. We don’t have to do anything. All we to do is learn. And then as adults, we take all those things that we learned when we babies and children and actually put them to work to do out there in the world.
So one way of thinking about it is that babies and children are like the research and development division of human species. So they’re the protected blue sky guys who just have go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas that learned when we were children and actually put them to use. Another way of thinking about it instead of thinking of babies and children as being like defective grownups, we should think about them being a different developmental stage of the same species — kind of like 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 our 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 are for learning, that’s what they’re — we might expect that they would have really powerful learning mechanisms. in fact, the baby’s brain seems to be the powerful learning computer on the planet. But real computers are actually getting to be a better. And there’s been a revolution in our understanding of machine learning recently. it all depends on the ideas of this guy, Reverend Thomas Bayes, who was a statistician and mathematician in 18th century. And essentially what Bayes did was to provide a 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 evidence. The evidence makes them change that hypothesis. Then they test that new hypothesis and so and so forth. And what Bayes showed was a mathematical way that you could do that. that mathematics is at the core of the best machine programs that we have now. And some 10 years ago, I suggested that babies might be the same thing.
So if you want to know what’s on underneath those beautiful brown eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies actually making complicated calculations with conditional probabilities that they’re revising to out how the world works. All right, now that might seem like even taller order to actually demonstrate. Because after all, you ask even grownups about statistics, they look extremely stupid. could it be that children are doing statistics?
So to this we used a machine that we have called the Detector. This is 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 babies are at learning about the world. Let me mention one that we did with Tumar Kushner, my student. I showed you this detector, you would be likely to think to with that the way to make the detector go would be to put a on top of the detector. But actually, this detector works in a of a strange way. Because if you wave a block over the top of detector, something you wouldn’t ever think of to begin with, the detector actually activate two out of three times. Whereas, if you do the likely thing, put the block on detector, it will only activate two out of six times. So the unlikely hypothesis actually has evidence. It looks as if the waving is a more effective than the other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked 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 are interesting about this. The first one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these complicated calculations that will give them a conditional probability measure. And the interesting thing is that they’re using that evidence to get an idea, get to a hypothesis about the world, that seems unlikely to begin with. And in studies we’ve just doing in my lab, similar studies, we’ve show that four year-olds are actually better at finding out unlikely hypothesis than adults are when we give them exactly the same task. in these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, and wanted to see if children are doing experiments. When children do experiments we it “getting into everything” or else “playing.”
And there’s been a bunch of interesting studies recently have shown this playing around is really a kind of experimental program. Here’s one from Cristine Legare’s lab. What Cristine was 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. And what you’ll see is this little boy will go through five hypotheses in the space of minutes.
(Video) Boy: How about this? Same as the other side.
Alison Gopnik: Okay, so his first hypothesis just been falsified.
(Laughter)
Boy: This one lighted up, this one nothing.
AG: Okay, he’s got his experimental out.
Boy: What’s making this light up. (Laughter) I don’t know.
AG: Every 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: this is his next idea. He told the experimenter to do this, to putting it out onto the other location. Not working either.
Boy: Oh, because the light goes 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 up. So when you put four. So you put four on this one to it light up and two on this one to make it light up.
AG: Okay,there’s fifth hypothesis.
Now that is a particularly — that is a particularly and articulate little boy, but what Cristine discovered is this is actually quite typical. If you at 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, if you back to those psychologists and philosophers, a lot of 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 babies and are actually more conscious than we are as adults. Now here’s we know about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens for is we decide that something’s relevant or important, we should pay attention it. Our consciousness of that thing that we’re attending to extremely bright and vivid, and everything else sort of goes dark. And we even know something about way the brain does this.
So what happens when we 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 have a very focused, purpose-driven kind of attention. If we look at and young children, we see something very different. I think babies and young children seem to more of a lantern of consciousness than a spotlight of consciousness. So babies and young are very bad at narrowing down to just one thing. they’re very good at taking in lots of information from lots of different sources at once. if you actually look in their brains, you see that they’re with these neurotransmitters that are really good at inducing learning plasticity, and the inhibitory parts haven’t come on yet. when we say that babies and young children are bad paying attention, what we really mean is that they’re bad at not 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 kind of attention, the kind of consciousness, that we might expect from those who are designed 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 thing is think about cases 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 in a new for the first time. And what happens then is not that consciousness contracts, it expands, so that those three days in Paris seem to be more full consciousness and experience than all the months of being a walking, talking, faculty meeting-attending back home. And by the way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics the 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 three 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 a grownup. I don’t want to say too much about how wonderful babies are. It’s good be a grownup. We can do things like tie our shoelaces and the street by ourselves. And it makes sense that put a lot of effort into making babies think adults do. But if what we want is to be like those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults start thinking more like children.
(Applause)