What is going on this baby’s mind? If you’d asked people this 30 years ago, most people, including psychologists, would said that this baby was irrational, illogical, egocentric — that he couldn’t take the of another person or understand cause and effect. In the last 20 years, developmental has completely overturned that picture. So in some ways, we think that this baby’s thinking is like the of the most brilliant scientists.
Let me give you one example of this. One thing that this baby be thinking about, that could be going on in his mind, trying to figure out what’s going on in the of that other baby. After all, one of the things that’s hardest for of us to do is to figure out what other people are thinking feeling. And maybe the hardest thing of all is to out that what other people think and feel isn’t actually like what we think and feel. Anyone who’s followed politics can testify to how hard that is for people to get. We wanted to know if babies and young could understand this really profound thing about other people. Now the is: How could we 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 beautiful stream consciousness monologue about ponies and birthdays and things like that. So do we actually ask them the question?
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it turns out that the secret was broccoli. What we did — Betty Rapacholi, was one of my students, and I — was actually to the babies two bowls of food: one bowl of raw and 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 was to take a little taste of food from each bowl. And she act as if she liked it or she didn’t. half the time, she acted as if she liked the crackers and didn’t like broccoli — just like a baby and any other sane person. But half time, what she would do is take a little of the broccoli and go, “Mmmmm, broccoli. I tasted 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 wanted just the opposite of what the babies wanted. We did this with 15 18 month-old babies. And then she would simply put her hand out say, “Can you give me some?”
So the question is: would the baby give her, what they liked or what liked? And the remarkable 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 she liked the broccoli. On the other hand, 15 month-olds stare at her for a long time if she as if she liked the broccoli, like they couldn’t figure out. But then after they stared for a long time, they would just give the crackers, what they thought everybody must like. So there are really remarkable things about this. The first one is that these 18 month-old babies have already discovered this really profound fact about human nature, that we don’t always want same thing. And what’s more, they felt that they should actually things to help other people get what they wanted.
Even more remarkably though, fact that 15 month-olds didn’t do this suggests that these 18 month-olds had this deep, profound fact about human nature in the three months from when they 15 months old. So children both know more and learn than we ever would have thought. And this is 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 children so much? And how is it possible for them to so much in such a short time? I mean, after all, if look at babies superficially, they seem pretty useless. And actually in many ways, they’re than useless, because we have to put so much time and energy into just keeping them alive. if we turn to evolution for an answer to this puzzle of 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, not just primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a relationship how long a childhood a species has and how big brains are compared to their bodies and how smart and flexible they are.
And sort of the for this idea are the birds up there. On one side is a New crow. And crows and other corvidae, ravens, rooks and so forth, incredibly smart birds. They’re as smart as chimpanzees in some respects. And this is 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 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 out that the babies, the New crow babies, are fledglings. They depend on their moms to drop worms in their open mouths for as long as two years, which is a really 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 in the soup pot.
There’s something about that long that seems to be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, the chicken, seem to be beautifully suited to doing just thing very well. So they seem to be beautifully suited to grain in one environment. Other creatures, like the crows, aren’t very good at doing anything in particular, they’re extremely good at learning about laws of different environments.
And course, we human beings are way out on the of the distribution like the crows. We have bigger relative to our bodies by far than any other animal. We’re smarter, we’re more flexible, we can learn more, we survive more different environments, we migrated to cover the world and even go to outer space. our babies and children are dependent on us for much longer than the babies of any species. My son is 23. (Laughter) And at least until they’re 23, we’re popping those worms into those little open mouths.
All right, why would see this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in world, but it has one big disadvantage. And that one big disadvantage is that, until you actually all that learning, you’re going to be helpless. So you don’t to have the mastodon charging at you and be saying to yourself, “A slingshot or maybe a might work. Which would actually be better?” You want know all that before the mastodons actually show up. And the way the evolutions seems have solved that problem is with a kind of division of labor. the idea is that we have this early period when we’re completely protected. We don’t to do anything. All we have to do is learn. And then as adults, we can take those things that we learned when we were babies and and actually put them to work to do things there in the world.
So one way of thinking about is that babies and young children are like the research and development division 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 we learned when we were children and actually put them use. Another way of thinking about it is instead of thinking of and children as being like defective grownups, we should about them as being a different developmental stage of the species — kind of like caterpillars and butterflies — except that they’re actually the brilliant butterflies who are around the garden and exploring, and we’re the caterpillars who are 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 are for learning, that’s they’re for — we might expect that they would have really powerful learning mechanisms. in fact, the baby’s brain seems to be the most powerful learning computer on the planet. But computers are actually getting to be a lot better. there’s been a revolution in our understanding of machine recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician and in the 18th century. And essentially what Bayes did was to provide a mathematical way using probability to characterize, describe, the way that scientists find out about the world. So what scientists is they have a hypothesis that they think might 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 showed was a mathematical way that you could do that. that mathematics is at the core of the best machine learning programs that we now. And some 10 years ago, I suggested that babies be doing the same thing.
So if you want know what’s going on underneath those beautiful brown eyes, think it actually looks something like this. This is Bayes’s notebook. So I think those babies are actually making complicated with conditional probabilities that they’re revising to figure out how the world works. right, now that might seem like an even taller order to actually demonstrate. Because all, if you ask even grownups about statistics, they look extremely stupid. How could it be that children doing statistics?
So to test this we used a machine that we have the Blicket Detector. This is a box that lights up and plays music when put some things on it and not others. And using very simple machine, my lab and others have done of studies showing just how good babies are at learning about the world. Let mention just one that we did with Tumar Kushner, my student. If I you this detector, you would be likely to think to begin with that the way to the detector go would be to put a block on of the detector. But actually, this detector works in a bit a strange way. Because if you wave a block the top of the detector, something you wouldn’t ever think of to with, the detector will actually activate two out of times. Whereas, if you do the likely thing, put block on the detector, it will only activate two out of six times. the unlikely hypothesis actually has stronger evidence. It looks as if the waving is a more effective than the other strategy. So we did just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And sure enough, four year-olds used the evidence to wave the object 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 quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re that evidence to get to an idea, get to a hypothesis about the world, that seems unlikely to begin with. And in studies we’ve just been in my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than are when we give them exactly the same task. So in these circumstances, the are using statistics to find out about the world, but all, scientists also do experiments, and we wanted to see if children are doing experiments. children do experiments we call it “getting into everything” else “playing.”
And there’s been a bunch of interesting studies recently that have shown this playing is really a kind of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine was use our Blicket Detectors. And what she did was show that yellow ones made it go and red ones didn’t, and she showed them an anomaly. And what you’ll see is that this boy will go through five hypotheses in the space two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and one nothing.
AG: Okay, he’s got his experimental 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 because this needs to like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this his next idea. He told the experimenter to do this, to try putting it onto the other location. Not working either.
Boy: Oh, because the light goes to here, not here. Oh, the bottom of this has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So you put four. So you put four on this one to make it up and two on this one to make it up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — that is a particularly adorable articulate little boy, but what Cristine discovered is this actually quite typical. If you look at the way children play, when you them to explain something, what they really do is do a of experiments. This is actually pretty typical of four year-olds.
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Well, what’s it like to be this kind creature? What’s it like to be one of these butterflies who can test five hypotheses in two minutes? Well, if go back to those psychologists and philosophers, a lot of them have that babies and young children were barely conscious if they were at all. And I think just the opposite is true. think babies and children are actually more conscious than are as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind of like spotlight. So what happens for adults is we decide that something’s relevant important, we should pay attention to it. Our consciousness of that thing that we’re attending to becomes extremely and vivid, and everything else sort of goes dark. And we even know something about the way brain does this.
So what happens when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a signal 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 of attention. If look at babies and young children, we see something very different. I think babies and young seem to have more of a lantern of consciousness a spotlight of consciousness. So babies and young children 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 flooded with these that are really good at inducing learning and plasticity, and inhibitory parts haven’t come on yet. So when we say babies and young children are bad at paying attention, we really mean is that they’re bad at not paying attention. So they’re at getting rid of all 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 those butterflies who are designed to learn.
Well if we want think about a way of getting a taste of 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 with someone new, or when we’re in new city for the first time. And what happens then is not that our contracts, it expands, so that those three days in Paris seem to be more of consciousness and experience than all the months of a walking, talking, faculty meeting-attending zombie back home. And by the way, that coffee, wonderful coffee you’ve been drinking downstairs, actually mimics the of those baby neurotransmitters. So what’s it like to a baby? It’s like being in love in Paris for first time after you’ve had three double-espressos. (Laughter) That’s a fantastic to be, but it does tend to leave you waking up at three 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 to be a grownup. We can do things like tie our shoelaces and cross the by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But what we want is to be like those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least some the time we should be getting the adults to start thinking more children.
(Applause)