What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, 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, developmental science completely overturned that picture. So in some ways, we that this baby’s thinking is like the thinking of most brilliant scientists.
Let me give you just one of this. One thing that this baby could be thinking about, that could be on in his mind, is trying to figure out what’s going on the mind of that other baby. After all, one of the things that’s hardest for all of to do is to figure out what other people are thinking feeling. And maybe the hardest thing of all is to figure out that what other think and feel isn’t actually exactly like what we think feel. Anyone who’s followed politics can testify to how that is for some people to get. We wanted know if babies and young children could understand this really profound thing about other people. the question is: How could we ask them? Babies, all, can’t talk, and if you ask a three year-old to tell you he thinks, what you’ll get is a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how do we actually ask them question?
footnote
Well it turns out that the was broccoli. What we did — Betty Rapacholi, who was one my students, and I — was actually to give the babies two bowls of food: one bowl of broccoli and one bowl of delicious goldfish crackers. Now of the babies, even in Berkley, like the crackers and don’t like the broccoli. (Laughter) But then what Betty did was to take a little taste of food from each bowl. she would act as if she liked it or she didn’t. half the time, she acted as if she liked crackers and didn’t like the broccoli — just like a and any other sane person. But half the time, she would do is take a little bit of the broccoli go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And then 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 just the opposite of what babies wanted. We did this with 15 and 18 month-old babies. then she would simply put her hand out and say, “Can give me some?”
So the question is: What would baby give her, what they liked or what she liked? And the thing was that 18 month-old babies, just barely walking and talking, give her the crackers if she liked the crackers, but would give her the broccoli 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 liked the broccoli, they couldn’t figure this out. But then after they stared for a long time, would just give her the crackers, what 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 about human nature, that we don’t always want the same thing. And what’s more, felt that they should actually do things to help other get what they wanted.
Even more remarkably 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 three months from they were 15 months old. So children both know and learn more than we ever would have thought. And this is just one of and hundreds of studies over the last 20 years that’s actually 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 a short time? I mean, after all, if you look at babies superficially, they pretty useless. And actually in many ways, they’re worse than useless, we have to put so much time and energy into keeping them alive. But if we turn to evolution for an answer this puzzle of why we spend so much time taking of useless babies, it turns out that there’s actually answer. If we look across many, many different species of animals, just us primates, but also including other mammals, birds, even marsupials kangaroos and wombats, it turns out that there’s a between how long a childhood a species has and how big their are compared to their bodies and how smart and they are.
And sort of the posterbirds for this idea are the up there. On one side is a New Caledonian crow. And crows and other corvidae, ravens, and so forth, are incredibly smart birds. They’re as smart as chimpanzees in some respects. And this a bird on the cover of science who’s learned 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 basically as dumb as dumps. So they’re very, very good at pecking for grain, and they’re not much at doing anything else. Well it turns out that babies, the New Caledonian crow babies, are fledglings. They 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 of months. So childhood is the reason why the crows end 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 and learning. Well what kind of explanation could we for this? Well some animals, like the chicken, seem to be beautifully to doing just one thing very well. So they seem to beautifully suited to pecking grain in one environment. Other creatures, like the crows, aren’t 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 end of the distribution like the crows. We have bigger brains relative to bodies by far than any other animal. We’re smarter, we’re flexible, we can learn more, we survive in more different environments, we migrated to cover the world and go to outer space. And our babies and children are dependent on 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 worms into those little open mouths.
All right, why would we see this correlation? Well an is that that strategy, that learning strategy, is an extremely powerful, strategy for getting on in the world, but it one big disadvantage. And that one big disadvantage is that, until you actually do that learning, you’re going to be helpless. So you don’t want to have the mastodon charging at and be saying to yourself, “A slingshot or maybe a spear work. Which would actually be better?” You want to know all before the mastodons actually 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 to anything. All we have to do is learn. And as adults, we can take all those things that we when we were babies and children and actually put them to to do things out there in the world.
So one way of about it is that babies and young children are like the research and division of the human species. So they’re the protected blue sky who just have to go out and learn and have good ideas, we’re production and marketing. We have to take all ideas 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 grownups, we should think about them as being a different developmental stage of the same — kind of like caterpillars and butterflies — except they’re actually the brilliant butterflies who are flitting around the garden exploring, and we’re the caterpillars who are inching along our narrow, grownup, adult path.
footnote
this is true, if these babies are designed to learn — and this evolutionary 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 to be the most powerful learning computer on planet. But real computers are actually getting to be a lot better. there’s been a revolution in our understanding of machine recently. And it all depends on the ideas of guy, the Reverend Thomas Bayes, who was a statistician mathematician in the 18th century. And essentially what Bayes did was to provide a mathematical way probability theory to characterize, describe, the way that scientists out about the world. So what scientists do is they have a hypothesis that they might be likely to start with. They 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 mathematical way that you could do that. And that mathematics is at the of the best machine learning programs that we have now. And 10 years ago, I 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 making complicated calculations with conditional probabilities they’re revising to figure out how the world works. All right, now that might like an even taller order to actually demonstrate. Because after all, you ask even grownups about statistics, they look extremely stupid. How could it be that children are statistics?
So to test this we used a machine that have called the Blicket Detector. This is a box that lights up and music when you put some 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 one that we did with Tumar Kushner, my student. If I you this detector, you would be likely to think to begin with that the way to make detector go would be to put a block on of the detector. But actually, this detector works in bit of a strange way. Because if you wave a block the top of the detector, something you wouldn’t ever think of begin with, the detector will actually activate two out three 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 actually has stronger evidence. It looks as if the waving is more effective strategy than the other strategy. So we did this; we gave four year-olds this pattern of evidence, and we just asked them make it go. And sure enough, the four year-olds used the evidence to wave the object on top the detector.
Now there are two things that are really about this. The first one is, again, remember, these four year-olds. They’re just learning how to count. But unconsciously, they’re doing these complicated calculations that will give them a conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, get to 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 that four year-olds are actually better finding out an unlikely hypothesis than adults are when we give them exactly the same task. So in circumstances, the children are using statistics to find out the world, but after all, scientists also do experiments, we wanted to see if children are doing experiments. When do experiments we call 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 what did was show children that yellow ones made it go and red ones didn’t, and then she showed an anomaly. And what you’ll see is that this little boy will go through five hypotheses the space of two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis has been falsified.
(Laughter)
Boy: This one lighted up, and this nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s this light up. (Laughter) I don’t know.
AG: Every scientist recognize that expression of despair.
(Laughter)
Boy: Oh, it’s this needs to be like this, and this needs be like this.
AG: Okay, hypothesis 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, the light goes only to here, not here. Oh, the bottom this box has electricity in here, but this doesn’t electricity.
AG: Okay, that’s a fourth hypothesis.
Boy: It’s lighting up. So when 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 boy, but what Cristine discovered is this is actually 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 four year-olds.
footnote
Well, what’s it like to be this kind of creature? What’s it like be one of these brilliant butterflies who can test five hypotheses two minutes? Well, if you go back to those psychologists philosophers, a lot of them have said that babies and young children were barely if they were conscious at all. And I think just the opposite is true. I think babies and are actually more conscious than we are as adults. Now here’s what we about how adult consciousness works. And adults’ attention and consciousness look kind of a spotlight. So what happens for adults is we decide 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 of goes dark. And we even know something about the way the does this.
So what happens when we pay attention is the prefrontal cortex, the sort of executive part of brains, sends a signal that makes a little part of our brain much 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, we see something very different. I think and young children seem to have more of a of consciousness than a spotlight of consciousness. So babies and young children are very bad at narrowing to just one thing. But they’re very good at taking in of information from lots of different sources at once. And if you actually look in their brains, you that they’re flooded with these neurotransmitters that are really good at inducing learning and plasticity, and inhibitory parts haven’t come on yet. So when we say that babies and young children bad at paying attention, what we really mean is they’re bad at not paying attention. So they’re bad getting rid of all the interesting things that could 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 butterflies who 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 cases where we’re put in a new situation that we’ve never been in before — when we fall in with someone new, or when we’re in a new city the first time. And what happens then is not our consciousness contracts, it expands, so that those three in Paris seem to be more full of consciousness and experience than 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 of those baby neurotransmitters. what’s it like to be a baby? It’s like being in love in Paris for the time after you’ve had three double-espressos. (Laughter) That’s a fantastic way be, but it does tend to leave you waking up crying at three o’clock in morning.
(Laughter)
Now it’s good to be a grownup. I don’t to say too much about how wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the by ourselves. And it makes sense that we put lot of effort into making babies think like adults do. But if we want is to be like those butterflies, to open-mindedness, open learning, imagination, creativity, innovation, maybe at least some of time we should be getting the adults to start thinking like children.
(Applause)