What going on in this baby’s mind? If you’d asked 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 in ways, we think that this baby’s thinking is like the thinking the most brilliant scientists.
Let me give you just example of this. One thing that this baby could be thinking about, that be going on in his mind, is trying to figure what’s going on in the mind of that other baby. After all, one of the things that’s for all of us to do is to figure out what other people are thinking and feeling. And the hardest thing of all is to figure out what other people think and feel isn’t actually exactly like we think and feel. Anyone who’s followed politics can testify to how hard is for some people to get. We wanted to know babies and young children could understand this really profound thing other people. Now the question is: How could we 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 a beautiful stream of consciousness monologue ponies and birthdays and things like that. So how we actually ask them the question?
footnote
Well it turns out the secret was broccoli. What we did — Betty Rapacholi, was one of my students, and I — was actually to the babies two bowls of 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 if she liked it or didn’t. So 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, what would do is take a little bit of the broccoli go, “Mmmmm, broccoli. I tasted the broccoli. Mmmmm.” And she would take a little bit of the crackers, she’d go, “Eww, yuck, crackers. I tasted the crackers. Eww, yuck.” she’d act as if what she wanted was just opposite of what the babies wanted. We did this with 15 18 month-old babies. And then she would simply put hand out and say, “Can you give me some?”
So question is: What would the baby give her, what they liked or what she liked? And the remarkable was that 18 month-old babies, just barely walking and talking, would give her the crackers if she the crackers, but they would give her the broccoli if she the broccoli. On the other hand, 15 month-olds would stare at her for a long if she acted as if she liked the broccoli, they 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 remarkable things about this. The one is that these little 18 month-old babies have already discovered this really profound fact about nature, that we don’t always want the same thing. And what’s more, they felt that 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 that these 18 month-olds had learned this deep, profound fact about nature in the three months from when they were 15 months old. So children know more and learn more than we ever would 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: Why do children learn much? And how is it possible for them to learn much in such a short time? I mean, after all, if you look babies superficially, they seem pretty useless. And actually in many ways, they’re worse than useless, we have to put so much time and energy just keeping them alive. But if we turn to evolution for an answer to this puzzle of we spend so much time taking care of useless babies, it turns out that there’s actually an answer. If look across many, many different species of animals, not just us primates, but also other mammals, birds, even marsupials like kangaroos and wombats, it turns that there’s a relationship between how long a childhood a species has and how big their brains are to their bodies and how smart and flexible they are.
And sort of posterbirds for this idea are the birds up there. On one side is a Caledonian crow. And crows and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re smart as chimpanzees in some respects. And this is a bird on the of science who’s learned how to use a tool to get food. On the other hand, we have friend the 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, and they’re not much good at doing 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 the reason why the end up on the cover of Science and the chickens end up in the soup pot.
There’s about that long childhood that seems to be connected 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 thing very well. they seem to be 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 learning about laws of different environments.
And of course, human beings are way out on the end of the distribution like the crows. We have bigger brains to our bodies by far than any other animal. We’re smarter, we’re more flexible, we can learn more, we survive more different environments, we migrated to cover the world and even go to outer space. And babies and children are dependent on us for much longer than the babies of any other species. 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 we see this correlation? Well an 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 big disadvantage is that, until you actually do all learning, you’re going to be 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. Which would actually better?” You want to know all that before the mastodons show up. And the way the evolutions seems to have solved that problem is a kind of division of labor. So the idea is that we have 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 we learned when we were babies and and actually put them to work 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 development of the human species. So they’re the protected blue sky guys who just have to out and learn and have good ideas, and we’re and marketing. We have to take all those 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 children being like defective grownups, we should think about them as 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 and exploring, and we’re the caterpillars are inching along our narrow, grownup, adult path.
footnote
If is true, if these babies are designed to learn — and this evolutionary story would 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 the most powerful learning computer on the planet. But real computers are actually to be a lot better. And there’s been a revolution in understanding of machine learning recently. And it all depends on ideas of this guy, the Reverend Thomas Bayes, who was a statistician and mathematician in the 18th century. essentially what Bayes did was to provide a mathematical way using probability theory to characterize, describe, the way scientists find out about the world. So what scientists do is they have hypothesis that they think might be likely to start with. go out and test it against the evidence. The evidence them change that hypothesis. Then they test that new hypothesis and so on and so forth. And what showed 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 babies be doing the same thing.
So if you want to know what’s going on those beautiful brown eyes, I think it actually looks something like this. This is 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, that might seem like an even 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 we used a machine we have called the Blicket Detector. This is a box that lights and plays music when you put some things on it not others. And using this very simple machine, my and others have done dozens of studies showing just how good babies are at learning about 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 the detector go would be to put a block on top of 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 activate two out three times. Whereas, if you do the likely thing, the block on the detector, it will only activate two out of times. So the unlikely hypothesis actually has stronger evidence. It as if the waving is a more effective strategy than other strategy. So we did just this; we gave year-olds this pattern of evidence, and we just asked them to make it go. sure enough, the four year-olds used the evidence to the object on top 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 conditional probability measure. And the other interesting thing is they’re using that evidence to get to an idea, get a hypothesis about the world, that seems very unlikely to with. And in studies we’ve just been doing in lab, similar studies, we’ve show that four year-olds are actually better at out an unlikely hypothesis than adults are when we them exactly the same task. So in these circumstances, the children are using statistics to find about the world, but after all, scientists also do experiments, and we to see if children are doing experiments. When children do experiments we call it “getting everything” or else “playing.”
And there’s been a bunch of interesting studies recently that shown this playing around is really a kind of research program. Here’s one from Cristine Legare’s lab. What did was use our Blicket Detectors. And what she did was show children yellow ones made it go and red ones didn’t, and then showed them an anomaly. And what you’ll see is that this little boy will through five hypotheses in the space of two minutes.
(Video) Boy: How about this? 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 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: this is his next idea. He told the experimenter do this, to try 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 has electricity in here, but this doesn’t have 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 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 discovered is this is actually quite typical. If you at the way children play, when you ask them to something, what they really do is do a series of experiments. This is actually typical of four year-olds.
footnote
Well, what’s it like to be this of creature? What’s it like to be one of these brilliant butterflies can test five hypotheses in two minutes? Well, if you go to those psychologists and philosophers, a lot of them have that babies and young children were barely conscious if they conscious at all. And I think just the opposite is true. I think babies and children are more conscious than we are as adults. Now here’s what we know about adult consciousness works. And 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 pay 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 something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, sort of executive part of our brains, sends a that makes a little part of our brain much more flexible, more plastic, better at learning, and down activity in all the rest of our brains. So we a very focused, purpose-driven kind of attention. If we look at babies young children, we see something very different. I think babies young children seem to have more of a lantern consciousness than a spotlight of consciousness. So babies and children are very bad at narrowing down to just thing. But they’re very good at taking in lots information from lots of different sources at once. And you actually look in their brains, you see that they’re flooded with these neurotransmitters are really good at inducing learning and plasticity, and the parts haven’t come on yet. So when we say that babies and young are bad at paying attention, what we really mean is that they’re at not paying attention. So they’re bad at getting of all the interesting things that could tell them something and just looking the thing that’s important. That’s the kind of attention, the kind of consciousness, we might expect from those butterflies who are designed to learn.
Well if we want to think about way of getting a taste of that kind of baby consciousness as adults, I think the thing is think about cases where we’re put in a new situation we’ve never been in before — when we fall love with someone new, or when we’re in a city for the first time. And what happens then not that our 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 back home. And by the way, that coffee, that coffee you’ve been drinking downstairs, actually mimics the effect of those baby neurotransmitters. So what’s it like to 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 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 say too much about how wonderful babies are. It’s to be a grownup. We can do things like our shoelaces and cross the street by ourselves. And it makes sense we put a lot of effort into making babies like adults do. But if what we want is to be like those butterflies, have 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)