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 last 20 years, developmental has completely overturned that picture. So in some ways, we think that this baby’s thinking like the thinking of the most brilliant scientists.
Let me give you just one example of this. One that this baby could be thinking about, that could be going on his mind, is trying to figure out what’s going on in the mind that other baby. After all, one of the things that’s hardest all of us to do is to figure out what people are thinking and feeling. And maybe the hardest thing of all is to figure out what other people think and feel isn’t actually exactly like what we think feel. Anyone who’s followed politics can testify to how hard that is 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: could we ask 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 beautiful stream of consciousness monologue about ponies and birthdays and things like that. So do we actually ask them the question?
footnote
Well it out that the secret was broccoli. What we did — Rapacholi, who was one of my students, and I — was actually to give babies two bowls of food: one bowl of raw and one bowl of delicious goldfish crackers. Now all 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 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 liked the crackers and didn’t like the — just like a baby and any other sane person. But half the time, what would do is take a little bit of the 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 wanted was the opposite of what the babies wanted. We did this with 15 and 18 month-old babies. then she would simply put her hand out and say, “Can you give me some?”
So question is: What would the baby give her, what they or what she liked? And the remarkable thing was that 18 month-old babies, just walking and talking, would give her the crackers if she liked the crackers, but they would give her broccoli if she liked the broccoli. On the other hand, 15 month-olds would stare her for a long time if she acted as if she liked the broccoli, like 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 things about this. The first one is that these little 18 month-old babies have already discovered this profound fact about human nature, that we don’t always the same thing. And what’s more, they felt that they should do things to help other people get what they wanted.
Even more remarkably though, the that 15 month-olds didn’t do this suggests that these 18 month-olds had this deep, profound fact about human nature in the three from when they were 15 months old. So children both know more learn more than we ever would have thought. And this is one of hundreds and hundreds of studies over the 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 such short time? I mean, after all, if you look at babies superficially, seem pretty useless. And actually in many ways, they’re worse than useless, because we to put so much time and energy into just keeping them alive. But if turn to evolution for an answer to this puzzle of why spend so much time taking care of useless babies, it turns out that there’s an answer. If we look across many, many different of animals, not just us primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a relationship between how a childhood a species has and how big their brains are compared to bodies and how smart and flexible they are.
And sort the posterbirds for this idea are the birds up there. On one side a New Caledonian crow. And crows and other corvidae, ravens, rooks and forth, are incredibly smart birds. They’re as smart as chimpanzees some respects. And this is a bird on the cover of science who’s how to use a tool to get food. On the other hand, we have our friend domestic chicken. And chickens and ducks and geese and turkeys are basically as as dumps. So they’re very, very good at pecking for grain, they’re not much good at doing anything else. Well it out that the babies, the New Caledonian crow babies, are fledglings. They depend on their to drop worms in their little open mouths for as as two years, which is a really long time in the life of a bird. Whereas chickens are actually mature within a couple of months. So childhood is the reason why the crows up on the cover of Science and the chickens end up in the soup pot.
There’s something that long childhood that seems to be connected to knowledge learning. Well what kind of explanation could we have for this? some animals, like the chicken, seem to be beautifully suited to just one thing very well. So they seem to be beautifully to pecking grain in one environment. Other creatures, like 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 beings are way out on the end of the like the crows. We have bigger brains relative to bodies by far than any other animal. We’re smarter, we’re more flexible, can learn more, we survive in more different environments, we migrated to the world and even go to outer space. And our babies and children dependent on us for 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 into little open mouths.
All right, why would we see correlation? Well an idea is that that strategy, that learning strategy, is an extremely powerful, great strategy for on in the world, but it has one big disadvantage. And that one big disadvantage that, until you actually do all that learning, you’re going to be helpless. So don’t want to have the mastodon charging at you and be to yourself, “A slingshot or maybe a spear might work. would actually be better?” You want to 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 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 that learned when we were babies and children and actually put to work to do things out there in the world.
So one way of thinking about it is 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 to go out and learn have good ideas, and we’re production and marketing. We have to take all 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 them as being a different developmental of the same species — kind of like caterpillars and butterflies — except that they’re actually brilliant butterflies who are flitting around the garden and exploring, we’re the caterpillars who are inching along our narrow, grownup, adult path.
footnote
If is true, if 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, baby’s brain seems to be the most powerful learning computer the planet. But real computers are actually getting to be a lot better. And there’s been 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 what Bayes did was to a mathematical way using probability theory to characterize, describe, the way that scientists find out about the world. what scientists do is they have a hypothesis that they think be likely to start with. They go out and test against the evidence. The evidence makes them change that hypothesis. Then they test that new and so on and so forth. And what Bayes was a mathematical way that you could do that. And that mathematics is at the core of the machine learning programs that we have now. And some 10 years ago, I suggested that might be doing the same thing.
So if you want to know what’s going on underneath those brown eyes, I think it actually looks something like this. This 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 an even taller order to actually demonstrate. Because after all, if you ask even grownups statistics, they look extremely stupid. How could it be that children are statistics?
So to test this we used a machine that we have called the Detector. This is a box that lights up and plays when you put some things on it and not others. And this very simple machine, my lab and others have done dozens of studies showing just good babies are at learning about the world. Let me mention just one we did with Tumar Kushner, my student. If I showed you this detector, you would likely to think to begin with that the way to make the detector go would be to put block on top of the detector. But actually, this works in a bit of a strange way. Because you wave a block over the top of the detector, something you wouldn’t ever think of begin with, the detector will actually activate two out of times. Whereas, if you do the likely thing, put the block on detector, it will only activate two out of six times. So the unlikely hypothesis actually stronger evidence. It looks as if the waving is a effective strategy than the other 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 wave the object on top of the detector.
Now there two things that are really interesting about this. The one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these quite calculations that will give them a conditional probability measure. the other interesting thing is that they’re using that evidence get to an idea, get to a hypothesis about the world, that seems unlikely to begin 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 hypothesis than adults are when we give them exactly the same task. So these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, and wanted to see if children are doing experiments. When children do we call it “getting into everything” or else “playing.”
And there’s been a bunch of studies recently that have shown this playing around is really a kind experimental research program. Here’s one from Cristine Legare’s lab. What Cristine did was use our Blicket Detectors. And 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 boy go through five hypotheses in the space of two minutes.
(Video) Boy: about this? Same as the other side.
Alison Gopnik: Okay, so first hypothesis has just been falsified.
(Laughter)
Boy: This lighted up, and this one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s this 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 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 here, but this 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 up and two on this one to make it light up.
AG: Okay,there’s his hypothesis.
Now that is a particularly — that is a particularly adorable and articulate little boy, what Cristine discovered 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 do a series of experiments. is actually pretty typical of four year-olds.
footnote
Well, what’s like to be this kind of creature? What’s it to be one of these brilliant butterflies who can test hypotheses in two minutes? Well, if you go back those psychologists and philosophers, a lot of them have said babies and young children were barely conscious if they conscious at all. And I think just the opposite is true. I think and children are actually more conscious than we are as adults. here’s what we know about how adult consciousness works. adults’ attention and consciousness look kind of like a spotlight. So what happens for 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 the way the brain does this.
So what happens we pay attention is that the prefrontal cortex, the sort of part of our brains, sends a signal that makes a little part of our brain much more flexible, plastic, better at learning, and shuts down activity in all the rest of our brains. So we a very focused, purpose-driven kind of attention. If we look babies and young children, we see something very different. I babies and young children seem to have more of lantern of consciousness than a spotlight of consciousness. So and young children are very bad at narrowing down just one thing. But 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 good at inducing learning and plasticity, and the inhibitory parts haven’t on yet. So when we say that babies and children are bad at paying attention, what we really mean that they’re bad at not paying attention. So they’re bad at getting rid all the interesting things that could tell them something and looking at 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 if we want to think about a way getting a taste of that kind of baby consciousness adults, I think the best thing is think about cases where we’re put in a new 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 contracts, it expands, so that those three days in Paris seem to be more full consciousness and experience than all the months of being a walking, talking, meeting-attending zombie back home. And by the way, that coffee, that wonderful you’ve been drinking downstairs, actually mimics the effect of those neurotransmitters. So what’s it like to be a baby? It’s like in love in Paris for the first time after you’ve had three double-espressos. (Laughter) That’s a fantastic to be, but it does tend to leave you waking up crying at o’clock in 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 a grownup. We do things like tie our shoelaces and cross the street ourselves. And it makes sense that we put a lot effort into making babies think like adults do. But what we want is to be like those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of the time we should getting the adults to start thinking more like children.
(Applause)