What is going on 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 the perspective another person or understand cause and effect. In the 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 baby could be thinking about, that could be going on in his mind, trying to figure out what’s going on in the mind that other baby. After all, one of the things that’s hardest for of us to do is to figure out what other people are and feeling. And maybe the hardest thing of all is figure out that what other people think and feel isn’t actually 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 if babies and young children understand this really profound thing about other people. Now question is: How could we ask them? Babies, after all, can’t talk, and if you a three year-old to tell you what he thinks, what you’ll get is a beautiful stream of consciousness about ponies and birthdays and things like that. So do we actually ask them the question?
footnote
Well it turns that the secret was broccoli. What we did — Betty Rapacholi, who was one my 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, the crackers and 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, acted as if she liked the crackers and didn’t like the broccoli — 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.” then she would take a little bit of the crackers, and she’d go, “Eww, yuck, crackers. I tasted crackers. Eww, yuck.” So she’d act as if what she was just the opposite of what the babies wanted. 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 baby her, what they liked or what she liked? And the remarkable thing that 18 month-old babies, just barely walking and talking, would give the 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 at her for a long time if she acted as if she liked broccoli, like they couldn’t figure this out. But then they stared for a long time, they would just her the crackers, what they thought everybody must like. So there are two really remarkable about this. The first one is that these little 18 month-old babies have discovered this really profound fact about human nature, that don’t always want the same thing. And what’s more, they felt that they should actually do things help other people get what they wanted.
Even more remarkably though, fact that 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 they were 15 months old. So children both know more and learn more than we ever have thought. And this is just one of hundreds 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 possible for them to learn so in such a short time? I mean, after all, if look at babies superficially, they seem pretty useless. And 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 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. we look across many, many different species of animals, not just primates, but also including other mammals, birds, even marsupials like kangaroos 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 smart flexible they are.
And sort of the posterbirds for this are the birds up there. On one side is a New Caledonian crow. crows and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart chimpanzees in some respects. And this is a bird the cover of science who’s learned how to use tool to get food. On the other hand, we have our friend the domestic chicken. And and ducks and geese and turkeys are basically as as dumps. So they’re very, very good at pecking grain, and they’re not much good at doing anything else. Well it turns out that the babies, New Caledonian crow babies, are fledglings. They depend on moms to drop worms in their little open mouths for as long as two years, which is really long time in the life of a bird. Whereas the chickens are actually mature a couple of months. So childhood is the reason why the crows end up on the cover Science and the chickens end up in the soup pot.
There’s something that long childhood that seems to be connected to knowledge and learning. Well what kind explanation could we have for this? Well some animals, like the chicken, seem to be beautifully suited doing just one thing very well. So they seem to beautifully suited to pecking grain in one environment. Other creatures, like crows, aren’t very good at 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 the end of 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 to cover the world and even go to outer space. And babies and children are dependent on us for much longer than the of any other species. My son is 23. (Laughter) And at least until they’re 23, we’re still those worms into those little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that strategy, is an extremely powerful, great strategy for getting on in world, but it has one big disadvantage. And that one big is that, until you actually do all that learning, you’re going to helpless. So you don’t want to have the mastodon at you and be saying to yourself, “A slingshot or maybe a spear might work. would actually be better?” You want to know all that the mastodons actually show up. And the way the evolutions to have solved that problem is with a kind division of labor. So the idea is that we 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 were babies and children and actually put them to work to do out there in the world.
So one way of thinking about is that babies and young children are like the research and development division of human species. So they’re the protected blue sky guys who just have go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas we learned when we were children and actually put to use. Another way of thinking about it is instead thinking of babies and children as being like defective grownups, we should think them as being 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 exploring, and we’re the caterpillars who are inching along narrow, grownup, adult path.
footnote
If this is true, these babies are designed to learn — and this story would say children are for learning, that’s what they’re for — we might expect that they would have powerful learning mechanisms. And in fact, the baby’s brain seems be the most powerful learning computer on the planet. But real computers are actually to be a lot better. And there’s been a in our understanding of machine learning recently. And it depends on the ideas of this guy, the Reverend Thomas Bayes, who was a statistician and mathematician in 18th century. And essentially what Bayes did was to provide a mathematical using probability theory to characterize, describe, the way that scientists find about the world. So what scientists do is they have a hypothesis that they think might be to start with. They go out and test it against evidence. The evidence makes them change that hypothesis. Then they test that new hypothesis and so on so forth. And what Bayes showed was a mathematical way that you do that. And that mathematics is at the core of the best machine learning programs that have now. And some 10 years ago, I suggested that babies might doing the same thing.
So if you want to 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 those babies are making complicated calculations with conditional probabilities that they’re revising to figure out the world works. All right, now that might seem like an taller order to actually demonstrate. Because after all, if you ask grownups about statistics, they look extremely stupid. How could be that children are doing statistics?
So to test this used a machine that we have called the Blicket Detector. is a box that lights up and plays music when put some things on it and not others. And using this very machine, my lab and others have done dozens of studies just how good babies are at learning about the world. Let me just one that we did with Tumar Kushner, my student. I showed you this detector, you would be likely to think to begin that the way to make the detector go would be to put a block on top of detector. But actually, this detector works in a bit of a strange way. if you wave a block over the top of the detector, something wouldn’t ever think of to begin with, the detector actually activate two out of three times. Whereas, if you the likely thing, put the block on the detector, it will only two out of six times. So the unlikely hypothesis actually stronger evidence. It looks 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, and we just them to make it go. And sure enough, the year-olds used the evidence to wave the object on of the detector.
Now there are two things that are really interesting about this. first one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these quite complicated that will give them a conditional probability measure. And the other thing is that they’re using that evidence to get to an idea, get to hypothesis about the world, that seems very unlikely to with. And in 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 hypothesis than adults when we give them exactly the same task. So in these circumstances, the children using statistics to find out about the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. When children do experiments we it “getting into everything” or else “playing.”
And there’s been a of interesting studies recently that have shown this playing is really a kind of experimental research program. Here’s one Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. And she did was show children that yellow ones made it go and red ones didn’t, and she showed them an anomaly. And what you’ll see is that little boy will go through 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 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 is his next idea. He the experimenter to do this, to try putting it out onto the location. Not working either.
Boy: Oh, because the light goes only to here, not here. Oh, 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 on this one to make it light up two on this one to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now is a particularly — that is a particularly adorable and articulate little boy, but 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 do series of experiments. This is actually pretty typical of year-olds.
footnote
Well, what’s it like to be this kind of creature? What’s like to be one of these brilliant butterflies who can test five hypotheses in two minutes? Well, if go back to those psychologists and philosophers, a lot them have said that babies and young children were conscious if they were conscious at all. And I think just the opposite is true. I think and children are actually more conscious than we are as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant or important, we pay attention to it. Our consciousness of that thing we’re attending to becomes extremely bright and vivid, and else sort of goes dark. And we even know about the way the brain does this.
So what happens when pay attention is that the prefrontal cortex, the sort executive 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 of our brains. So we have a focused, purpose-driven kind of attention. If we look at babies and children, we see something very different. I think babies and young children seem to have more a lantern of consciousness than a spotlight of consciousness. So babies and young children are very at narrowing down to just one thing. But they’re good at taking in lots of information from lots different sources at once. And if you actually look in their brains, you see that they’re flooded with neurotransmitters that are really good at inducing learning and plasticity, and the inhibitory parts haven’t come on yet. So we say that babies and young children are bad at attention, what we really mean is that they’re bad not paying attention. So they’re bad at getting rid of the interesting things that could tell them something and just looking at the thing that’s important. That’s the of 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 of consciousness as adults, I think the best thing is think about cases where we’re put a new situation that we’ve never been in before — when we fall in love someone new, or when we’re in a new city for the first time. And happens then is not that our consciousness contracts, it expands, so that three days in Paris seem to be more full of consciousness experience 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 effect of baby neurotransmitters. So what’s it like to be a baby? It’s being in love in Paris for the first time after you’ve had three double-espressos. (Laughter) That’s a way to be, but it does tend to leave you waking up crying three o’clock in the morning.
(Laughter)
Now it’s good be a grownup. I don’t want to say too much about how wonderful babies are. It’s to be a grownup. We can do things like tie shoelaces and cross the street by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. 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)