What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, would have that this baby was irrational, illogical, egocentric — that couldn’t take the perspective of another person or understand and effect. In the last 20 years, developmental science has completely overturned that picture. in some ways, we think that this baby’s thinking is like the thinking of the most scientists.
Let me give you just one example of this. One thing that this baby could be thinking about, could be going on in his mind, is trying figure out what’s going on in the mind of that other baby. After all, of the things that’s hardest for all of us to do to figure out what other people are thinking and feeling. And maybe the hardest thing of all is to out that what other people think and feel isn’t actually exactly like what we think feel. Anyone who’s followed politics can testify to how hard that is for people to get. We wanted to know if babies and children could understand this really profound thing about other people. the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old tell you what he thinks, what you’ll get is a beautiful of consciousness monologue about ponies and birthdays and things like that. So how do we actually them the question?
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Well it turns out the secret was 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 and one bowl of delicious goldfish crackers. Now all of the babies, even in Berkley, like crackers and don’t like the raw broccoli. (Laughter) But then what Betty did was to take a little of food from each bowl. And she would act if she liked it or she didn’t. So half the time, she acted if she liked the crackers and didn’t like the — just like a baby and any other sane person. But half time, what she would do is take a little bit of broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take little bit of the crackers, and 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 what the 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 is: What would the baby give her, what they liked or she liked? And the remarkable thing was that 18 month-old babies, barely walking and talking, would give her the crackers if she liked the crackers, but they give her the broccoli if she liked the broccoli. the other hand, 15 month-olds would stare at her for a long time if she acted as if 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 really remarkable things about this. The first one is that these 18 month-old babies have already discovered this really profound fact about nature, that we don’t always want the same thing. And what’s more, felt that they should actually do things to help people get what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds had this deep, profound fact about human nature in the months from when they were 15 months old. So children know more and learn more than we ever would thought. And this is 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 children learn 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 pretty useless. And actually in many ways, they’re worse useless, because we have to put so much time and energy into just them alive. But if we turn to evolution for an answer to this puzzle why we spend so much time taking care of useless babies, it out that there’s actually an 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 how and flexible they are.
And sort of the posterbirds for idea are the birds up there. On 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 in some respects. And this is a bird on the cover science who’s learned how to use a tool to food. On the other hand, we have our friend the chicken. And chickens and ducks and geese and turkeys are as dumb as dumps. So they’re very, very good at pecking for grain, they’re not much good at doing anything else. Well it turns that the babies, the New Caledonian crow babies, are fledglings. They on their moms to drop worms in their little open mouths for as as two years, which is a really long time the life of a bird. Whereas the chickens are actually mature within couple of months. So childhood is the reason why the crows end up on the cover of and the chickens end up in the soup pot.
There’s about that long childhood that seems to be connected knowledge and learning. Well what kind of explanation could we for this? Well some animals, like the chicken, seem be beautifully suited to doing just one thing very well. So seem to be beautifully suited to pecking grain in environment. Other creatures, like the crows, aren’t very good doing anything in particular, but they’re extremely good at learning about laws of different environments.
And course, we human beings are way out on the end of the distribution like the crows. have bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to cover world and even go to outer space. And our babies and are dependent on us for much longer than the babies of other species. My son is 23. (Laughter) And at least until they’re 23, we’re still popping those into those little open mouths.
All right, why would we see this correlation? Well an idea that that strategy, that learning strategy, is an extremely powerful, great for getting on in the world, but it has one disadvantage. And that one big disadvantage is that, until actually do 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 a spear might work. Which would actually be better?” You want know all that before the mastodons actually show up. And the the evolutions seems to have solved that problem is with a kind of of labor. So the idea is that we have early period when we’re completely protected. We don’t have do anything. All we have to do is learn. And then as adults, we can all those things that we learned when we were babies 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 young children like the research and development division of the human species. So they’re the blue sky guys who just have to go out and learn and have ideas, and we’re production and marketing. We have to take all those ideas we learned when we were children and actually put them to use. Another way of thinking about is instead of thinking of babies and children as like defective grownups, we should think about them as being a different stage of the same species — kind of like caterpillars and butterflies — that they’re actually the brilliant butterflies who are flitting around the garden and exploring, we’re the caterpillars who are inching along our narrow, grownup, path.
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If this is true, if these babies designed to learn — and this evolutionary story would say children are learning, that’s what they’re for — we might expect that would have really powerful learning mechanisms. And in fact, the baby’s brain seems to the most powerful learning computer on the planet. But real computers actually getting to be a lot better. And there’s been a revolution in our understanding machine learning recently. And it all depends on the ideas this guy, the Reverend Thomas Bayes, who was a statistician mathematician in the 18th century. And essentially what Bayes did was to provide mathematical way using probability theory to characterize, describe, the way that scientists find about the world. So what scientists do is they have hypothesis that they think might be likely to start with. They go out and it against the evidence. The evidence makes them change that hypothesis. Then they test that new and so on and so forth. And what Bayes showed was a mathematical way you could do that. And that mathematics is at the core of the best learning programs that we have now. And some 10 years ago, I suggested that babies might doing the same thing.
So if you want to know what’s on underneath those beautiful brown eyes, I think it looks something like this. This is Reverend Bayes’s notebook. So I think those babies are making complicated calculations with conditional 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 stupid. How could it be that children are doing statistics?
So test this we used a machine that we have called the 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 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 showed you detector, you would be likely to think to begin with that the way to make detector go would be to put a block on top the detector. But actually, this detector works in a bit of a strange way. Because you wave a block over the top of the detector, something wouldn’t ever think of to begin with, the detector will actually activate out of three times. Whereas, if you do the thing, put the block on the detector, it will only activate two out six times. So the unlikely hypothesis actually has stronger evidence. It as if the waving is a more effective strategy than the other strategy. So did just this; we gave four year-olds this pattern of evidence, we just asked them to make it go. And enough, the four year-olds used the evidence to wave object on top of the detector.
Now there are two things that really interesting about this. The first one is, again, remember, these are four year-olds. They’re just how to count. But unconsciously, they’re doing these quite calculations that will give them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, get to a hypothesis the world, that seems very unlikely to begin with. And studies we’ve just been doing in my lab, similar studies, we’ve show four year-olds are actually better at finding out an unlikely than adults are when we give them exactly the same task. in these circumstances, the children are using statistics to find out about the world, but after all, scientists do experiments, and we wanted to see if children are doing experiments. children do experiments we 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 from Cristine Legare’s lab. What Cristine did was use Blicket Detectors. And what she did was show children that yellow made it go and red ones didn’t, and then showed them an anomaly. And what you’ll see is this little boy will go through five hypotheses in space of two minutes.
(Video) Boy: How 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 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 this needs to be like this, and this needs be like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: this is his next idea. He told the experimenter to this, to try putting it out onto the other location. Not working either.
Boy: Oh, because the goes only 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 this one to make it light up and two this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now is a particularly — that is a particularly adorable and little boy, but what Cristine discovered is this is actually quite typical. If you look at the children play, when you ask them to explain something, what they really do is a series of experiments. This is actually pretty typical 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 test five hypotheses in two minutes? Well, if you go back to psychologists and philosophers, a lot of them have said that and young children were barely conscious if they were conscious at all. And I think just opposite is true. I think babies and children are more conscious than we are as adults. Now here’s what we know about how 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 extremely bright and vivid, and everything else sort of goes dark. And we know something about the way the brain does this.
So what happens when we pay attention is the prefrontal cortex, the sort of executive part of our brains, sends a signal that a little part of our brain much more flexible, more plastic, better at learning, and down activity in all the rest of our brains. So we have a very focused, purpose-driven of attention. If we look at babies and young children, see something very different. I think babies and young children seem to have more of a lantern consciousness than a spotlight of consciousness. So babies and young children are very bad at narrowing down to one thing. But they’re very good at taking in lots of information from lots of sources at once. And if you actually look in brains, you see that 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 that babies and children are bad at paying attention, what we really is that they’re bad at not paying attention. So they’re bad at getting rid of all the interesting that could tell them something and just looking at 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 the best thing think about cases where we’re put in a new that we’ve never been in before — when we in love with someone new, or when we’re in a city for the first time. And what happens then is not our consciousness contracts, it expands, so that those three days in Paris seem to be full of consciousness and experience than all the months of being a walking, talking, faculty meeting-attending zombie home. And by the way, that coffee, that wonderful you’ve been drinking downstairs, actually mimics the effect of baby neurotransmitters. So what’s it like to be a baby? It’s like being in love Paris for the 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 be a grownup. don’t want to say too much about how wonderful are. It’s good to be a grownup. We can do things tie our shoelaces and cross the street by ourselves. And makes sense that we put a lot of effort making babies think like adults do. But if what we want to be like those 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)