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