What is going in this baby’s mind? If you’d asked people 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 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 of the most brilliant scientists.
Let me give you one example of this. One thing that this baby could be about, that could be going on in his mind, is trying to figure out what’s going on the mind of that other baby. After all, one the things that’s hardest for all of us to is to figure out what other people are thinking and feeling. maybe the hardest thing of all is to figure that what other people think and feel isn’t actually like what we think and feel. Anyone who’s followed can testify to how hard that is for some people to get. We to know if babies and young children could understand this really profound about other people. Now the question is: How could ask them? Babies, after all, can’t talk, and if you a three year-old to tell you what he thinks, you’ll get is a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how we actually ask them the question?
footnote
Well turns out that 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 broccoli 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 would as if she liked it or she didn’t. So half the time, she acted as if she liked crackers and didn’t like the broccoli — just like a baby and any other sane person. But the time, what she would do is take a little bit the broccoli and go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a little of the crackers, and she’d go, “Eww, yuck, crackers. I 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 out and say, “Can you give me some?”
So question is: What would the baby give her, what they liked or she liked? And the remarkable thing was that 18 month-old babies, just barely walking and talking, would give her crackers if she liked the crackers, but they would her the broccoli if she liked the broccoli. On the 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 after they stared for long time, they would just give her the crackers, they thought everybody must like. So there are two remarkable things about this. The first one is that little 18 month-old babies have already discovered this really profound fact human nature, that we don’t always want the same thing. what’s more, they felt that they should actually do things to other 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 learned deep, profound fact about human nature in the three months from when were 15 months old. So children both know more and learn more we ever would have thought. And this is just of hundreds and hundreds of studies over the last 20 that’s actually demonstrated it.
footnote
The question you might ask though is: Why do children so much? And how is it possible for them learn so much in such a short time? I mean, all, if you look at babies superficially, they seem useless. And actually in many ways, they’re worse than useless, because we to put so much time and energy into just keeping alive. But if we turn to evolution for an to this puzzle of why we spend so much time care of useless babies, it turns out that there’s actually an answer. If we look across many, many species of animals, not just us primates, but also including mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s relationship between how long a childhood a species has how big their brains are compared to their bodies how smart and flexible they are.
And sort of the for this idea are the birds up there. On side is a New Caledonian crow. And crows and other corvidae, ravens, rooks so forth, are 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 a tool to get 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 pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, New Caledonian 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 long time in the 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 seems to be connected to and learning. Well what kind of explanation could we for this? Well some animals, like the chicken, seem to be beautifully suited to just one thing very well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t very at doing anything in particular, but they’re extremely good learning about laws of different environments.
And of course, human beings are way out on the end of the distribution like the crows. We have bigger brains to our bodies by far than any other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated cover the world and even go to outer space. And our babies and children are 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 worms into those little open mouths.
All right, why we see this correlation? Well an idea is that that strategy, learning strategy, is an extremely powerful, great strategy for getting on in the world, it has one big disadvantage. And that one big disadvantage is that, until actually do all that learning, you’re going to be helpless. you 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 before the mastodons show up. And the way the evolutions seems to have 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 have do anything. All we have to do is learn. And as adults, we can take all those things that we learned when we babies and children and actually put them to work to do things out there in world.
So one way of thinking about it is that babies and young are 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 have good ideas, and we’re production and marketing. We have take all those ideas that we learned when we were children and put them to use. Another way of thinking about it is instead of thinking of babies and as being like defective grownups, we should think about as being 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.
footnote
If this is true, these babies are 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 seems to be the most powerful learning computer on planet. But real computers are actually getting to be a better. And there’s been a revolution in our understanding of learning recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who 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 that scientists find out about the world. So what scientists do is they have hypothesis that they think might be likely to start with. go out and test it against the evidence. The makes them change that hypothesis. Then they test that new hypothesis so on and so forth. And what Bayes showed was a mathematical way that you could that. And that mathematics is at the core of best machine learning programs that we have now. And some 10 years ago, suggested that babies might be doing the same thing.
So if you to know what’s going on underneath those beautiful brown eyes, I think it actually looks something like this. This Reverend Bayes’s notebook. So I think those babies are actually complicated calculations with conditional probabilities that they’re revising to figure out how the world works. right, now that might seem like an even taller to actually demonstrate. Because after all, if you ask 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 have the Blicket Detector. This is a box that lights up and plays music when you put things on it and not others. And using this very simple machine, lab and others have done dozens of studies showing just good babies are at learning about the world. Let me mention just that we did with Tumar Kushner, my student. If showed you this detector, you would be likely to to begin with that the way to make the detector go be to put a block on top of the detector. actually, this detector works in a bit of a strange way. Because if you wave a block the top of the detector, something you wouldn’t ever think of to begin with, the detector actually activate two out of three times. Whereas, if you do the likely thing, put the on the detector, it will only activate two out of six times. So 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 pattern of evidence, and we just asked them to make go. And sure enough, the four year-olds used the to wave the object on top of the detector.
Now there are things that are really interesting about this. The first is, again, remember, these are four year-olds. They’re just learning how count. But unconsciously, they’re doing these quite complicated calculations will give them a conditional probability measure. And the other interesting thing is that they’re using evidence to get to an idea, get to a hypothesis about world, that seems very unlikely to begin with. And in we’ve just been doing in my lab, similar studies, we’ve show that four year-olds are actually better at out an unlikely hypothesis than adults are when we give them the same task. So in these circumstances, the children are using statistics to find out the world, but after all, scientists also do experiments, and we wanted to see children are doing experiments. When children do experiments we call it “getting into everything” or “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 from Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. And what she was show children that yellow ones made it go and red didn’t, and then she showed them an anomaly. And you’ll see is that this little boy will go five hypotheses in the space of two minutes.
(Video) Boy: How about this? as the other side.
Alison Gopnik: Okay, so his hypothesis has just been falsified.
(Laughter)
Boy: This one 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 recognize 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 try putting it onto the other location. Not working either.
Boy: Oh, because the light goes only 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. when you put four. So you put four on one to make it light up and two on this to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is a particularly — that is a particularly and articulate little boy, but what Cristine discovered is is actually quite typical. If you look at the way children play, when you them to explain something, what they really do is a series of experiments. This is actually pretty typical four year-olds.
footnote
Well, what’s it like to this kind of creature? What’s it like to be one of these brilliant butterflies can test five hypotheses in two minutes? Well, if you go to those psychologists and philosophers, a lot of them have said that and young children were barely conscious if they were at all. And I think just the opposite is true. I think babies and children actually more conscious than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and look kind of like a spotlight. So what happens adults is we decide that something’s relevant or important, we should pay attention to it. Our consciousness of thing that we’re attending to becomes extremely bright and vivid, and everything else sort of goes dark. And even know something about the way the brain does this.
So what happens when we 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 activity in all the rest of our brains. So have a very focused, purpose-driven kind of attention. If we at babies and young children, we see something very different. I 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 just one thing. But they’re very good at taking 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 neurotransmitters that are really at inducing learning and plasticity, and the inhibitory parts haven’t come yet. So when we say that babies and young children are bad at paying attention, we really mean is that they’re bad at not paying attention. they’re bad at getting rid of all the interesting things could tell them something and just looking at the thing that’s important. That’s the kind attention, the kind of consciousness, that we might expect from those butterflies are designed to learn.
Well if we want to think a way of getting a taste of that kind baby consciousness as adults, I think the best thing is about cases where we’re put in a new situation that we’ve never been in before — when we in love with someone new, or when we’re in a new city for the time. And what happens then is not that our consciousness contracts, it expands, so that three days in Paris seem to be more full of consciousness and experience all the months of being a walking, talking, faculty meeting-attending zombie back home. And by way, that coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics the effect those baby neurotransmitters. So what’s it like to be a baby? It’s like being in love in for the first time after you’ve had three double-espressos. (Laughter) That’s a fantastic way to be, but it does 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 much about how wonderful babies are. It’s good to be grownup. We can do things like tie our shoelaces and cross street 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, have open-mindedness, open learning, imagination, creativity, innovation, maybe at some of the time we should be getting the adults to thinking more like children.
(Applause)