What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would have said that baby was irrational, illogical, egocentric — that he couldn’t take the perspective of another person understand cause and effect. In the last 20 years, developmental science has completely overturned that picture. So in ways, we think that this baby’s thinking is like thinking of the most brilliant scientists.
Let me give you just one of this. One thing that this baby could be about, that could be going on in his mind, trying 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 are thinking and feeling. And the hardest thing of all is to figure out that what other people think and isn’t actually exactly like what we think and feel. Anyone who’s followed politics can testify to how hard is for some people to get. We wanted to know babies and young children could understand this really profound thing about people. Now the question is: How could we ask them? Babies, after all, can’t talk, and if you ask a year-old to tell you what he thinks, what you’ll get is a stream of consciousness monologue about ponies and birthdays and things that. So how do we actually ask them the question?
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Well it out that the secret was broccoli. What we did — Rapacholi, who was one of my students, and I — actually to give the babies two bowls of food: one bowl of raw and one bowl of delicious goldfish crackers. Now all of babies, even in Berkley, like the crackers and don’t the raw broccoli. (Laughter) But then what Betty did was to take a taste of food from each bowl. And she would as if she liked it or she didn’t. So half time, she acted as if she 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 bit the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” 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 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 hand out and say, “Can you give me some?”
So the question is: What would the give her, what they liked or what she liked? the remarkable thing was that 18 month-old babies, just walking and talking, would give her the crackers if she liked crackers, but they would give her the broccoli if liked the broccoli. On the other hand, 15 month-olds stare at her for a long time if she acted if she liked the broccoli, like they couldn’t figure out. But then after they stared for a long time, would just give her the crackers, what they thought everybody like. So there are two really remarkable things about this. The first one is these little 18 month-old babies have already discovered this really fact about human nature, that we don’t always want the same thing. And what’s more, they felt they should actually do things to help other people get what they wanted.
Even more though, the fact that 15 month-olds didn’t do this suggests these 18 month-olds had learned this deep, profound fact about human 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 is just one of hundreds and hundreds of studies over the last 20 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 learn so much in such a 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 to evolution for an answer to this puzzle of why we spend so time taking care of useless babies, it turns out that there’s an answer. If we look across many, many different species of animals, not us primates, but also including other mammals, birds, even like kangaroos and wombats, it turns out that there’s a between how long a childhood a species has and big their brains are compared to their bodies and how smart and flexible are.
And sort of the posterbirds for this idea 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 respects. And this is a bird on the cover of science who’s learned how use a tool to get food. On the other hand, we have our friend the chicken. And chickens and ducks and geese and turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much good at doing anything else. Well it out that the babies, the New Caledonian crow babies, are fledglings. They depend on their to drop worms in their little 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 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 to be connected to and learning. Well what kind of explanation could we have for this? Well animals, like the chicken, seem to be beautifully suited doing just one thing very well. So they seem to be suited to pecking grain in one environment. Other creatures, like the crows, aren’t good at doing anything in particular, but they’re extremely good at learning laws of different environments.
And of course, we human beings way out on the end of the distribution like crows. We have bigger brains relative to our bodies by far than any 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 outer space. And our babies and children are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at until 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, great strategy for getting on the world, but it has one big disadvantage. And that one big disadvantage is that, until you do all that learning, you’re going to be helpless. So don’t want to have the mastodon charging at you be saying to yourself, “A slingshot or maybe a might work. Which would actually be better?” You want to know all that before mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind of division of labor. So the idea is that 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 take all those things that we learned when we were babies and children and actually them to work to do things out there in 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 have to go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas that we learned we were children and actually put them to use. Another way thinking about it is instead of thinking of babies and as being like defective grownups, we should think about them as a different developmental stage of the same species — kind of like caterpillars and — 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 is true, if these babies are designed 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. And fact, the baby’s brain seems to be the most powerful learning computer the planet. But real computers are actually getting to be a lot better. And there’s been a revolution our understanding of machine learning recently. And it all on the ideas of this guy, the Reverend Thomas Bayes, was a statistician and mathematician in the 18th century. essentially what Bayes did was to provide a mathematical way using probability theory characterize, describe, the way that scientists find out about world. So what scientists do is they have a hypothesis they think might be likely to start with. They go and test it against the evidence. The evidence makes them change 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 now. And some 10 years ago, I suggested that babies might doing the same thing.
So if you want to know what’s going on underneath those brown eyes, I think it actually looks something like this. This Reverend Bayes’s notebook. So I think those babies are actually making complicated calculations with probabilities that they’re revising to figure out how the works. All right, now that might seem like an even taller to actually demonstrate. Because after all, if you ask even grownups about statistics, they look extremely stupid. could it be that children are doing statistics?
So to test this we used machine that we have called the Blicket Detector. This is a box that lights up and plays when you put some things on it and not others. using this very simple machine, my lab and others done dozens of studies showing just how good babies at learning about the world. Let me mention just that we did with Tumar Kushner, my student. If I you this detector, you would be likely to think to with that the way to make the detector go would to put a block on top of the detector. But actually, this detector works in a bit of strange way. Because if you wave a block over the of the detector, something you wouldn’t ever think of to with, the detector will actually activate two out of three times. Whereas, if you do likely thing, put the block on the detector, it will only two out of six times. So the unlikely hypothesis has stronger evidence. It looks as if the waving a more effective strategy than the other strategy. So did just this; we gave four year-olds this pattern of evidence, and we just them to make it go. And sure enough, the four year-olds used the to wave the object on top of the detector.
Now there are two things that are really 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 quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re using that evidence to get to idea, get 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 actually better finding out an unlikely hypothesis than adults are when give them exactly the same task. So in these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, and we wanted to see if children are experiments. When children do experiments we call it “getting into everything” or else “playing.”
And there’s been a of interesting studies recently that have shown this playing around is really a of experimental research program. Here’s one from Cristine Legare’s lab. What did was use our Blicket Detectors. And what she did show children that yellow ones made it go and red ones didn’t, and then she showed them anomaly. And what you’ll see is that this little boy will go through five hypotheses in the space two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis has just been falsified.
(Laughter)
Boy: one lighted up, and this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making light up. (Laughter) I don’t know.
AG: Every scientist will that expression of despair.
(Laughter)
Boy: Oh, it’s because this needs be like this, and this needs to be like this.
AG: Okay, two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. told the experimenter to do this, to try putting it onto the other location. Not working either.
Boy: Oh, 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 a hypothesis.
Boy: It’s lighting up. So when you put four. So you four on this one to make it light up and on this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that a particularly — that is a particularly adorable and articulate little boy, but Cristine discovered is this is actually quite typical. If you at the way children play, when you ask them to explain something, they really do is do a series of experiments. This is 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 brilliant butterflies who can test hypotheses in two minutes? Well, if you go back to psychologists and philosophers, a lot of them have said that babies and young were barely conscious if they were conscious at all. I think just the opposite is true. I think babies and children 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 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 everything else of goes dark. And we even know something about the way the does this.
So what happens when we pay attention is that the cortex, the sort of executive part of our brains, a signal that makes a little part of our brain more flexible, more plastic, better at learning, and shuts down activity all the rest of our brains. So we have very focused, purpose-driven kind of attention. If we look at babies and young children, we see something different. I think babies and young children seem to have more of a lantern of consciousness than spotlight of consciousness. So babies and young children are bad at narrowing down to just one thing. But they’re good at taking in lots of information from lots of different sources at once. And if actually look in 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 are bad at paying attention, what we really mean is they’re bad at not paying attention. So they’re bad getting rid of all the interesting things that could tell something and just looking 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 a taste of that kind of baby consciousness as adults, I think best thing is think about cases where we’re put a new situation that we’ve never been in before — we fall in love with someone new, or when we’re in a city for the first time. And what happens then not that our consciousness contracts, it expands, so that those three days in Paris seem to more full of consciousness and experience than all the months of being walking, talking, faculty meeting-attending zombie back home. And by the way, that coffee, that wonderful you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it like to a baby? It’s like being in love in Paris for the time after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, it 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 babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street ourselves. And it makes sense that we put a lot 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 of the time we should be getting the adults start thinking more like children.
(Applause)