What is going on 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 the perspective of another person or understand cause and effect. In the 20 years, developmental science has completely overturned that picture. So some ways, we think that this baby’s thinking is 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 in his mind, is to figure out what’s going on in the mind of that other baby. After all, one of the that’s hardest for all of us to do is figure out what other people are thinking and feeling. And maybe the hardest thing all is to figure out 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 wanted know if babies and young children could understand this profound thing about other people. Now the question is: How could ask them? Babies, after all, can’t talk, and if you ask a three year-old tell you what he thinks, what you’ll get is beautiful stream of consciousness monologue about ponies and birthdays things like that. So how do we actually ask the question?
footnote
Well it turns out that the secret broccoli. What we did — Betty Rapacholi, who was one of my students, I — was actually to give the babies two bowls of food: one of raw broccoli and one bowl of delicious goldfish crackers. Now all of the babies, even Berkley, like the crackers and don’t like the raw broccoli. (Laughter) But then Betty did was to take a little taste of food from each bowl. And would act as if she liked it or she didn’t. So half the time, she as if she liked the crackers and didn’t like broccoli — just like a baby and any other sane person. half the time, what she would do is take little bit of the broccoli and go, “Mmmmm, broccoli. tasted the broccoli. Mmmmm.” And then she would take a little bit of crackers, and she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” So she’d act as if she wanted was just the opposite of what the wanted. We did this with 15 and 18 month-old babies. And then she would simply her hand out and say, “Can you give me some?”
So question is: What would the baby give her, what they liked 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 stare at her for a long time if she acted as if liked the broccoli, like they couldn’t figure this out. But after they stared for a long time, they would just give the crackers, what they thought everybody must like. So there are really 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. And what’s more, they that they should actually do things to 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 this deep, profound about human nature in the three months from when they 15 months old. So children both know more and learn more than ever would have thought. And this is just one of hundreds and of studies over the last 20 years that’s actually it.
footnote
The question you might ask though is: do children learn so much? And how is it possible them to learn so much in such a short time? I mean, after all, if you at babies superficially, they seem pretty useless. And actually in ways, they’re worse than useless, because we have to put so much time and energy into just keeping alive. But if we turn to evolution for an answer to this puzzle 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 species of animals, not just us primates, but also including other mammals, birds, even marsupials like and wombats, it turns out that there’s a relationship between how long a a species has and how big their brains are compared to their bodies and how smart and they are.
And sort of the posterbirds for this idea are the birds 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 as in some respects. And this is a bird on cover of science who’s learned how to use a tool get food. On the other hand, we have our friend domestic chicken. And chickens and ducks and geese and turkeys are basically as dumb dumps. So they’re very, very good at pecking for grain, and they’re not much good at anything else. Well it turns out that the babies, the New crow babies, are fledglings. They depend on their moms to drop worms in little open mouths for as long as two years, which a really long time in the life of a bird. Whereas chickens are actually mature within a couple of months. So childhood is the why the crows end up on the cover of Science and the chickens up in the soup pot.
There’s something about that long childhood seems to be connected to knowledge and learning. Well what kind of explanation could we have for this? some animals, like the chicken, seem to be beautifully suited to doing just one very well. So they seem to be beautifully suited to pecking in one environment. Other creatures, like the crows, aren’t very good at doing in particular, but they’re extremely good at learning about of different environments.
And of course, we human beings are way out the end of the distribution like the crows. We have bigger brains relative to our bodies far than any other animal. We’re smarter, we’re more flexible, we can more, we survive in more different environments, we migrated to cover the world and even go outer space. And our babies and children are dependent on us for much longer than the babies any other species. My son is 23. (Laughter) And at least until they’re 23, we’re still popping those 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 in 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 want have the mastodon charging at you and be saying to yourself, “A slingshot or a spear might work. Which would actually be better?” You want know all that before the mastodons actually show up. And the way the evolutions seems have solved that problem is with a kind of division of labor. the idea is that we have this early period we’re completely protected. We don’t have to do anything. All we have to is learn. And then as adults, we can take those things that we learned when we were babies and children actually put them to work to do things out there in world.
So one way of thinking about it is that and young children are like the research and development of the human species. So they’re the protected blue sky guys who have to go out and learn and have good ideas, and we’re and marketing. We have to take all those ideas that we learned we were children and actually put them to use. Another way of thinking it is instead of thinking of babies and children as being like defective grownups, we should think them as being a different developmental stage of the same — kind of like caterpillars and butterflies — except that they’re actually the 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 to learn — this evolutionary story would say children are for learning, that’s what they’re for — might expect that they would have really powerful learning mechanisms. And fact, the baby’s brain seems to be the most powerful computer on the planet. But real computers are actually to be a lot better. And there’s been a revolution our understanding of machine learning recently. And it all depends on the ideas this guy, the Reverend Thomas Bayes, who was a statistician and in the 18th century. And essentially what Bayes did was to provide a mathematical way probability theory to characterize, describe, the way that scientists find out about world. So what scientists do is they have a hypothesis that they think might be likely start with. They go out and test it against the evidence. The evidence makes change that hypothesis. Then they test that new hypothesis and so on so forth. And what Bayes showed was a mathematical way you could 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 might be doing the same thing.
So if you want to know what’s going underneath those beautiful brown eyes, I think it actually looks something like this. This is Reverend Bayes’s notebook. I think those babies are actually making complicated calculations with conditional probabilities that they’re to figure out how the world works. All right, now that might seem like even taller order to actually demonstrate. Because after all, if you ask even grownups about statistics, look extremely stupid. How could it be that children are doing statistics?
So test this we used a machine that we have called the Detector. This is a box that lights up and plays music you put some things on it and not others. using this very simple machine, my lab and others have done dozens studies showing just how good babies are at learning about the world. Let me mention just that we did with Tumar Kushner, my student. If I showed you detector, you would be likely to think to begin with that the to make the detector go would be to put a block on of the detector. But actually, this detector works in a bit a strange way. Because if you wave a block over the top of detector, something you wouldn’t ever think of to begin with, the detector will actually two out of three times. Whereas, if you do the thing, put the block on the detector, it will only activate out of six times. So the unlikely hypothesis actually has stronger evidence. It looks as if the is a more effective strategy than the other strategy. we did just this; we gave four year-olds this pattern evidence, and we just asked them to make it go. sure enough, the four year-olds used the evidence to wave the object on of the detector.
Now there are two things that really interesting about this. The first one is, again, remember, are four year-olds. They’re just learning how to count. unconsciously, they’re doing these quite complicated calculations that will give them a conditional measure. And the other interesting thing is that they’re using that to get to an idea, get to a hypothesis the world, that seems very unlikely to begin with. And in studies we’ve just been doing my lab, similar studies, we’ve show that four year-olds are actually better at finding an unlikely hypothesis than adults are when we give them exactly same task. So in these circumstances, the children are using to find out about the world, but after all, scientists also do experiments, and wanted to see if children are doing experiments. When do experiments we call it “getting into everything” or “playing.”
And there’s been a bunch of interesting studies recently that have this playing 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 did was show children that yellow ones made it go and red didn’t, and then she showed them an anomaly. And what you’ll see is that this boy will go through five hypotheses in the space of two minutes.
(Video) Boy: about this? Same as the other side.
Alison Gopnik: Okay, so his first has just been falsified.
(Laughter)
Boy: This one lighted up, and one nothing.
AG: Okay, he’s got his experimental notebook out.
Boy: What’s making this 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 be like this.
AG: Okay, 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 other location. Not working either.
Boy: Oh, because the goes only to here, not here. Oh, the bottom of box has electricity in 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 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 — that is a particularly adorable 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 of four year-olds.
footnote
Well, what’s it like be this kind of creature? What’s it like to be 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 conscious they were conscious at all. And I think just the opposite is true. I babies and children are actually more conscious than we as adults. Now here’s what we know about how adult consciousness works. adults’ attention and consciousness look kind of like a spotlight. So happens for adults is we decide that something’s relevant or important, we should 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 way the brain does this.
So what happens when pay attention is that the prefrontal cortex, the sort of part of our brains, sends a signal that makes little part of our brain much more flexible, more plastic, better at learning, and shuts down activity in all rest of our brains. So we have a very focused, purpose-driven kind of attention. If we look babies and young children, we see something very different. I think babies and young seem to have more of a lantern of consciousness than spotlight of consciousness. So babies and young children are very at narrowing down to just one thing. But they’re very good at taking in lots of from lots of different sources at once. And if you actually look in 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 on yet. So when say that babies and young children are bad at paying attention, we really mean is that they’re bad at not attention. So they’re bad at getting rid of all interesting things that could tell them something and just looking at the that’s important. That’s the kind of attention, the kind of consciousness, that we might from those butterflies who are designed to learn.
Well if we want think about a way of getting a taste of that kind of baby consciousness as adults, think the best thing is think about cases where we’re put in new situation that we’ve never been in before — when we fall in love with someone new, or we’re in a new city for the first time. what happens then is not that our consciousness contracts, it expands, so that three days in Paris seem to be more full consciousness and experience than all the months of being walking, talking, faculty meeting-attending zombie back home. And by the way, coffee, that wonderful coffee you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s like to be a baby? It’s like being in love Paris for the first 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 want to say too about how wonderful babies are. It’s good to be grownup. We can do things like tie our shoelaces and cross the street by ourselves. And it makes that we put a lot of 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 should be getting the adults to start thinking more children.
(Applause)