What is going on in baby’s mind? If you’d asked people this 30 years ago, people, including psychologists, would have said that this baby was irrational, illogical, — that he couldn’t take the perspective of another person understand cause and effect. In the last 20 years, science has completely overturned that picture. So in some ways, we think this 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 be thinking about, could be going on in his mind, is trying to out what’s going on in the mind of that baby. After all, one of the things that’s hardest for all of us to do is 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 and feel. Anyone who’s followed politics can testify to hard that is for some people to get. We to know if babies and young children could understand this really thing about other people. Now the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old to tell you what he thinks, you’ll get is a beautiful stream of consciousness monologue about ponies and and things like that. So how do we actually ask the question?
footnote
Well it turns out that the secret was broccoli. What we — Betty Rapacholi, who was one of my students, and — 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 raw broccoli. (Laughter) But what Betty did was to take a little taste food from each bowl. And she would act as she liked it or she didn’t. So half the time, she as if she liked the crackers and didn’t like the broccoli — just like a baby and other sane person. But half the time, what she do is take a little bit of the broccoli go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then she would take a little bit of crackers, and she’d go, “Eww, yuck, crackers. I tasted crackers. Eww, yuck.” So she’d act as if what she wanted was just the of what the babies wanted. We did this with 15 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 the baby give her, what they or what she liked? And the remarkable thing was that 18 month-old babies, barely walking and talking, would give her the crackers she liked the crackers, but they would give her broccoli if she liked the broccoli. On the other hand, 15 month-olds would stare at her for a long time if acted as if she liked the broccoli, like they couldn’t this out. But then after they stared for a long time, they would just give her crackers, what they thought everybody must like. So there are two remarkable things about this. The first one is that these little 18 month-old babies have already this really profound fact about human nature, that we don’t want the same thing. And what’s more, they felt they should actually do things to help other people get what they wanted.
Even remarkably though, the fact that 15 month-olds didn’t do this suggests that 18 month-olds had learned this deep, profound fact about human in the three months from when they were 15 months old. So both 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 that’s actually demonstrated it.
footnote
The question you might though is: Why do children learn so much? And how is it possible them to learn so much in such a short time? I mean, all, if you 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 and energy just keeping them alive. But if we turn to evolution for an answer this puzzle of why we spend so much time taking care of useless babies, it turns out 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 marsupials like kangaroos and wombats, turns out that there’s a relationship between how long childhood a species has and how big their brains compared to their bodies and how smart and flexible they are.
And sort of the posterbirds for this are the birds up there. On one side is a New Caledonian crow. And and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart as chimpanzees some respects. And this is a bird on the cover of who’s learned how to use a tool to get food. the other hand, we have our friend the domestic chicken. And chickens and ducks and geese turkeys are basically as dumb as dumps. So they’re very, good at pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, the New Caledonian crow babies, are fledglings. They depend 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 mature within a couple of months. So childhood is reason why the crows end up on the cover Science and the chickens end up in the soup pot.
There’s about that long childhood that seems to be connected to knowledge and learning. what kind of explanation could we have 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 at doing anything in particular, they’re extremely good at learning about laws of different environments.
And of course, we human beings are way on the end of the distribution like the crows. We bigger brains relative to our bodies by far than other animal. We’re smarter, we’re more flexible, we can learn more, we survive in more different environments, migrated to cover the world and even go to outer space. our babies and children are dependent on us for much longer than the babies of any 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 would see this correlation? Well an idea is that that strategy, learning strategy, is an extremely powerful, great strategy for getting on the world, but it has one big disadvantage. And that one big disadvantage is that, until you do all that learning, you’re going to be helpless. So you don’t to have the mastodon charging at you and be saying yourself, “A slingshot or maybe a spear might work. Which actually be better?” You want to know all that the mastodons actually show up. And the way the evolutions seems to solved that problem is with a kind of division of labor. So 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 then as adults, we can take all those that we learned when we were babies and children and put them to work to do things out there in world.
So one way of thinking about it is babies and young children are like the research and development division of the human species. they’re the protected blue sky guys who just have to go and learn and have good ideas, and we’re production and marketing. We have to take all those that we learned when we were children and actually put to use. Another way of thinking about it is of thinking of babies and children as being like defective grownups, we should about them as being a different developmental stage of 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.
footnote
If this is true, if these babies are designed 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 be the powerful learning computer on the planet. But real computers are getting to be a lot better. And there’s been revolution in our understanding of machine learning recently. And all depends on the ideas of this guy, the Reverend Thomas Bayes, who a statistician and mathematician in the 18th century. And essentially what Bayes 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 they have a that they think might be likely to start with. They out 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 showed a mathematical way that you could do that. And that mathematics is the core of the best machine learning programs that we now. And some 10 years ago, I suggested that might be doing the same thing.
So if you want know what’s going on underneath those beautiful brown eyes, I think it actually looks something like this. is Reverend Bayes’s notebook. So I think those babies actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, that might seem like an even taller order to demonstrate. Because after all, if you ask even grownups about statistics, they look extremely stupid. How could be that children are doing statistics?
So to test this we used machine that we have called the Blicket Detector. This is a that lights up and plays music when you put things on it and not others. And 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 with Kushner, my student. If I showed you this detector, you would be to think to begin with that the way to make the detector go would be put a block on top of the detector. But actually, detector works in a bit of a strange way. if you wave a block over the top of detector, something you wouldn’t ever think of to begin with, the detector actually activate two out of three times. Whereas, if do the likely thing, put the block on the detector, will only activate two out of six times. So the hypothesis actually has stronger evidence. It looks as if the waving is more effective strategy than the other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked them make it go. And sure enough, the four year-olds the evidence to wave the object on top of detector.
Now there are two things that are really interesting this. The first one is, again, remember, these are year-olds. They’re just learning how to count. But unconsciously, they’re doing these quite complicated calculations that give them a conditional probability measure. And the other thing is that they’re using that evidence to get an idea, get to a hypothesis about the world, that very unlikely to begin with. And in studies we’ve just doing in my lab, similar studies, we’ve show that four year-olds actually better at finding out an unlikely hypothesis than are when we give them exactly the same task. in these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. children do experiments we call it “getting into everything” else “playing.”
And there’s been a bunch of interesting studies recently that have shown this around is really a kind of experimental research program. Here’s one from Cristine Legare’s lab. Cristine did was use our Blicket Detectors. And what she did was show that yellow ones made it go and red ones didn’t, then she showed them an anomaly. And what you’ll is that this little boy will go through five hypotheses in space of two minutes.
(Video) Boy: How about this? Same as the side.
Alison Gopnik: Okay, so his first hypothesis has just falsified.
(Laughter)
Boy: This one lighted up, and this 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 that expression of despair.
(Laughter)
Boy: Oh, it’s because needs to be like this, and this needs to like this.
AG: Okay, hypothesis two.
Boy: That’s why. Oh.
(Laughter)
AG: Now this is his next idea. He told experimenter to do this, to try putting it out onto the other location. working either.
Boy: Oh, because the light goes only to here, not here. Oh, bottom of this box 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 it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, but what Cristine is this is actually 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 year-olds.
footnote
Well, what’s it like to be this kind creature? What’s it like to be one of these brilliant butterflies who can test five in two minutes? Well, if you go back to those and philosophers, a lot of them have said that babies young children were barely conscious if they were conscious all. And I think just the opposite is true. I babies and children are actually more conscious than we are as adults. here’s what we know about how adult consciousness works. And adults’ attention and consciousness kind of like a spotlight. So what happens for adults is we decide something’s relevant or important, we should pay attention 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 the way the brain does this.
So happens when we pay attention is that the prefrontal cortex, the sort of executive part of our brains, sends signal that makes a little part of our brain more flexible, more plastic, better at learning, and shuts down activity in the rest of our brains. So we have a focused, purpose-driven kind of attention. If we look at babies and young children, we something very different. I think babies and young children to have more of a lantern of consciousness than spotlight of consciousness. So babies and young children are bad at narrowing down to just one thing. But they’re very good taking in lots of information from lots of different sources at once. And if you actually in 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 come on yet. when we say that babies and young children are bad at attention, what we really mean is that they’re bad at not 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 the kind of attention, kind of consciousness, that we might expect from those butterflies are designed to learn.
Well if we want to about a way of getting a taste of that kind of baby consciousness as adults, I the best thing is think about cases where we’re in a new situation that we’ve never been in — when we fall in love with someone new, or we’re in a new city for the first time. And what happens then is not that consciousness contracts, it expands, so that those three days Paris seem to be more full of consciousness and than all the months of being a walking, talking, faculty meeting-attending zombie back home. And the 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 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, it 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 much how wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street by ourselves. And makes sense that we put a lot of effort into making babies think like do. But if what we want is to be those butterflies, to have open-mindedness, open learning, imagination, creativity, innovation, maybe at some of the time we should be getting the to start thinking more like children.
(Applause)