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 take the perspective of another or understand cause and effect. In the last 20 years, developmental science has completely overturned that picture. in some ways, we think that this baby’s thinking like the thinking of the most brilliant scientists.
Let give you just one example of this. One thing that this baby could thinking about, that could be going on in his mind, is trying to figure out what’s going in the mind of that other baby. After all, one of the things that’s hardest for all us to do is to figure out what other people are thinking and feeling. maybe the hardest thing of all is to figure out that what other people think and feel isn’t exactly like what we think and feel. Anyone who’s followed politics can testify to how hard that for some people to get. We wanted to know if babies young children could understand this really profound thing about other people. Now the question is: How could we them? Babies, after all, can’t talk, and if you ask three year-old to tell you what he thinks, what you’ll get is a beautiful of consciousness monologue about ponies and birthdays and things like that. how do we actually ask them the question?
footnote
Well it out that the secret was broccoli. What we did — Betty Rapacholi, who was one of students, and I — was actually to give the babies two bowls food: one bowl of raw broccoli and one bowl of delicious goldfish crackers. all of the babies, even in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take a little taste of from each bowl. And she would act as if she it or she didn’t. So half the time, she acted as if she the crackers and didn’t like the broccoli — just like a and any other sane person. But half the time, she would do is take a little bit of 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 as if what she wanted was just the opposite of what the babies wanted. We this with 15 and 18 month-old babies. And then she would put her hand out and say, “Can you give me some?”
So question is: What would the baby give her, what they liked or what she liked? And the thing was 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 broccoli if liked the broccoli. On the other hand, 15 month-olds would stare at her for a long time she acted as if she liked the broccoli, like they couldn’t figure this out. then after they stared for a long time, they just give her the crackers, what they thought everybody must like. So there are two really things about this. The first one is that these little 18 month-old babies have already discovered really profound fact about human nature, that we don’t always want the thing. And what’s more, they felt that they should actually do things to help other get what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds had learned deep, profound fact about human nature in the three months when they were 15 months old. So children both know more and learn than we ever would have thought. And this is just one of hundreds and hundreds of studies over last 20 years that’s actually demonstrated it.
footnote
The question you might ask though is: Why children learn so much? And how is it possible for them to learn so much in a short time? I mean, after all, if you look at superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, because we have to put much time and energy into just keeping them alive. But if we turn to evolution an answer to this puzzle of why we spend much time taking care of useless babies, it turns out there’s actually an answer. If we look across many, many different species animals, not just us primates, but also including other mammals, birds, even 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 their bodies and how smart and flexible they are.
And sort of the posterbirds this idea are the birds up there. On one side a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as as chimpanzees in some respects. And this is a on the cover of science who’s learned how to a 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. So they’re very, very good at for grain, and they’re not much good at doing anything else. it turns out that the babies, the New Caledonian crow babies, are fledglings. depend on their moms to drop worms in their little open mouths as long as two years, which is a really long time in the of a bird. Whereas the chickens are actually mature within a couple months. So childhood is the reason why the crows end up on the of Science and the chickens end up in the soup pot.
There’s something about that childhood that seems to be connected to knowledge and learning. Well what of explanation could we have for this? Well some animals, the chicken, seem to be beautifully suited to doing one thing very well. So they seem to be beautifully suited to pecking grain one environment. Other creatures, like the crows, aren’t very good doing anything in particular, but they’re extremely good at about laws of different environments.
And of course, we human beings are way out on end of the distribution like the crows. We have bigger brains relative to our by far than any other animal. We’re smarter, we’re flexible, we can learn more, we survive in more different environments, we migrated to cover the and even go 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 those little open mouths.
All right, why would we this correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in the world, but it has big disadvantage. And that one big disadvantage is that, until you actually 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 work. Which would actually be better?” You want to know all that the mastodons actually show up. And the way the evolutions seems to have that problem is with a kind of division of labor. So the is that we have this early period when we’re completely protected. We don’t have do anything. All we have to do is learn. then as adults, we can take all those things we learned when we were babies and children and actually put them work to do things out there in the world.
So one 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 go out and learn and good ideas, and we’re production and marketing. We have to take all those ideas that learned when we were children and actually put them to use. Another of thinking about it is instead of thinking of babies and children as like defective grownups, we should think about them as being different developmental stage of the same species — kind of like caterpillars and butterflies — that they’re actually the brilliant butterflies who are flitting the garden and exploring, and we’re the caterpillars who are inching our narrow, grownup, adult path.
footnote
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 learning mechanisms. And in fact, the baby’s brain seems be the most powerful learning computer on the planet. real 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 mathematician in the 18th century. And essentially what Bayes did was to a mathematical way using probability theory to characterize, describe, the way that scientists out about the 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 that hypothesis. Then test that new hypothesis and so on and so forth. And what Bayes was a mathematical way that you could do that. And mathematics is at the core of the best machine 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 going on those beautiful brown eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies are 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. How could it that children are doing statistics?
So to test this we used a machine that we called the Blicket Detector. This is a box that lights up and music 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 are at learning the world. Let me mention just one that we did Tumar Kushner, my student. If I showed you this detector, you be likely to think to begin with that the way to make the detector go would to put a block on top of the detector. But actually, this detector works a bit of a strange way. Because if you wave a block over top of the detector, something you wouldn’t ever think of to begin with, detector will actually activate two out of three times. Whereas, if do the likely thing, put the block on the detector, it only activate two out of six times. So the unlikely hypothesis actually has stronger evidence. It looks as the waving is a more effective strategy than the strategy. So we did just this; we gave four year-olds this of evidence, and we just asked them to make go. And sure enough, the four year-olds used the evidence to wave the object top of the detector.
Now there are two things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning to count. But unconsciously, they’re doing these quite complicated calculations will give them a conditional probability measure. And the interesting thing is that they’re using that evidence to get to an idea, get to hypothesis about the world, that seems very 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 an unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using statistics to find out about world, but after all, scientists also do experiments, and we wanted to see if children doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of interesting studies recently that have shown playing around is really a kind of experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did was our Blicket Detectors. And what she did was show that yellow ones made it go and red ones didn’t, and then showed them an anomaly. And what you’ll see is that this 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 hypothesis has just been falsified.
(Laughter)
Boy: This one lighted up, and this one nothing.
AG: Okay, he’s his experimental notebook out.
Boy: What’s making this light up. (Laughter) don’t know.
AG: Every scientist will recognize 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 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 goes only to here, not here. Oh, the bottom of this 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 it light up and two on this one to make it up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — is a particularly adorable and articulate little boy, but what Cristine discovered is this is quite typical. If you look at the way children play, you ask them to explain something, what they really do is a series of experiments. This is actually pretty typical of four year-olds.
footnote
Well, what’s it to be this kind of creature? What’s it like to one of these brilliant butterflies who can test five hypotheses in two minutes? Well, if you back to those psychologists and philosophers, a lot of them have said that and young children were barely conscious if they were conscious at all. And think just the opposite is true. I think babies and children are more conscious than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and consciousness look kind of like spotlight. So what happens for adults is we decide that something’s relevant or important, we should attention to it. Our consciousness of that thing that we’re attending to becomes extremely bright and vivid, everything else sort of goes dark. And we even know something about the way the does this.
So what happens when we pay attention is that the prefrontal cortex, the sort of part of our brains, sends a signal that makes a part of our brain much more flexible, more plastic, better learning, and shuts down activity in all the rest our brains. So we have a very focused, purpose-driven kind attention. If we look at babies and young children, we see something very different. think babies and young children seem to have more of a lantern of consciousness than a spotlight consciousness. So babies and young children are very bad at narrowing down to just one thing. they’re very good at taking in lots of information lots of different sources at once. And if you actually look their brains, you see that they’re flooded with these neurotransmitters that are really good inducing learning and plasticity, and the inhibitory parts haven’t on yet. So when we say that babies and young are bad at paying attention, what we really mean is that they’re at not paying attention. So they’re bad at getting rid of the interesting things that could tell them something and just looking the thing that’s important. That’s the kind of attention, the kind of consciousness, that might expect from those butterflies who are designed to learn.
Well we want to think about a way of getting taste of that kind of baby consciousness as adults, I think the best thing is think cases where we’re put in a new situation that we’ve never been in before — when fall in love with someone new, or when we’re a new city for the first time. And what then is not that our consciousness contracts, it expands, that those three days in Paris seem to be more full of consciousness and than all the months of being a walking, talking, 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 the first after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but does tend to leave you waking up crying at three o’clock the morning.
(Laughter)
Now it’s good to be a grownup. I don’t want to say too about how wonderful babies are. It’s good to be grownup. We can do things like tie our shoelaces cross the street by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But if what we is to be like those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, at least some of the time we should be getting adults to start thinking more like children.
(Applause)