What is going on in this baby’s mind? you’d asked people this 30 years ago, most people, including psychologists, have said that this baby was irrational, illogical, egocentric — that he couldn’t take the perspective of 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 is like the thinking of the most brilliant scientists.
Let me give you one example of this. One thing that this baby could be thinking about, that could be going in his mind, is trying to figure out what’s going on the mind of that other baby. After all, one of things that’s hardest for all of us to do is to figure out what other people are and feeling. And maybe the hardest thing of all is to figure out that what people think and feel isn’t actually exactly like what think 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 profound thing about other people. Now the question is: could we 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 a beautiful stream consciousness monologue about ponies and birthdays and things like that. So how do actually ask them the question?
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Well it turns out the secret was broccoli. What we did — Betty Rapacholi, who 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 of the babies, even in Berkley, like the crackers don’t like the raw broccoli. (Laughter) But then what Betty did to take a little taste of food from each bowl. And she would act as if liked it or she didn’t. So half the time, she acted as if she liked the 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 and 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 was just the opposite of what the babies wanted. We did this 15 and 18 month-old babies. And then she would simply put her hand and say, “Can you give me some?”
So the question is: What would the give her, what they liked or what she liked? And the remarkable thing that 18 month-old babies, just barely walking and talking, would her the crackers if she liked the crackers, but they would give her the 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 really remarkable things about this. The first one is that these little 18 month-old babies already discovered this really profound fact about human nature, that we don’t always the same thing. And what’s more, they felt that they should actually do things to help people get what they wanted.
Even more remarkably though, the fact 15 month-olds didn’t do this suggests that these 18 month-olds had learned this deep, profound fact about human nature 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 demonstrated it.
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question you might ask though is: Why do children so much? And how is it possible for them learn so much in such a short time? I mean, after all, if you at 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 into just keeping them alive. But if we turn evolution for an answer to this puzzle of why spend so much time taking care of useless babies, it turns that there’s actually an answer. If we look across many, many different species of animals, not just us primates, 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 are compared to their bodies how smart and flexible they are.
And sort of the posterbirds for this idea are the birds there. On one side is 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 who’s learned how to use a tool to get food. On 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, very good at pecking for grain, and they’re not good at doing anything else. Well it turns out that babies, the New Caledonian crow babies, are fledglings. They depend on their moms to drop worms in little open 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 couple of months. So childhood is the reason why the crows end up on the cover of 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? Well some animals, the chicken, seem to be beautifully suited to doing one thing very well. So they seem to be suited to pecking grain in one environment. Other creatures, 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 have bigger brains relative our 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 and even go to outer space. And our babies and are dependent on us for much longer than the babies of other 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 we see this correlation? Well an idea that that strategy, that learning strategy, is an extremely powerful, great strategy getting on in the world, but it has one big disadvantage. that one big disadvantage is that, until you actually do all 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 would actually be better?” You want to know that before the mastodons actually show up. And the way the evolutions seems to have solved that is with a kind of division of labor. So the idea is that we have this early when we’re completely protected. We don’t have to do anything. All have to do is learn. And then as adults, can take all those things that we learned when we were babies and children and put them to work to do things out there in the world.
So one of thinking about it is that 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 take all those ideas that we learned when we children and actually put them to use. Another way of thinking about it is instead of thinking of and children as being like defective grownups, we should think about them as being a different developmental of the same species — kind of like caterpillars butterflies — except that they’re actually the brilliant butterflies are flitting around the garden and exploring, and we’re the caterpillars are inching along our narrow, grownup, adult path.
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this is true, if these babies are designed to learn — and this evolutionary would say children are for learning, that’s what they’re — we might expect that they would have really powerful mechanisms. And in fact, the 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 a revolution our understanding of machine learning recently. And it all depends on the of this guy, the Reverend Thomas Bayes, who was a statistician and mathematician the 18th century. And essentially what Bayes did was to provide a mathematical using probability theory to characterize, describe, the way that scientists find out about the world. So what do is they have a hypothesis that they think might be likely to start with. They out and test it against the evidence. The evidence makes them change that hypothesis. they test that new hypothesis and so on and so forth. what Bayes showed was a mathematical way that you do that. And that mathematics is at the core the best machine learning programs that we have now. some 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. is Reverend Bayes’s notebook. So I think those babies are actually making calculations with conditional probabilities that they’re revising to figure out the world works. All right, now that might seem like even taller order to actually demonstrate. Because after all, if ask even grownups about statistics, they look extremely stupid. How could it that children are doing statistics?
So to test this used a machine that we have called the Blicket Detector. is a box that lights up and plays music when put some things on it and not others. And using this very machine, my lab and others have done dozens of studies showing just how good babies at learning about the world. Let me mention just that we did with Tumar Kushner, my student. If showed you this detector, you would be likely to think to begin that the way to make the detector go would be to put block on top of the detector. But actually, this detector works in a of a strange way. Because if you wave a block over the top of the detector, you wouldn’t ever think of to begin with, the detector will activate two out of three times. Whereas, if you do the likely thing, put the block on detector, it will only activate two out of six times. So unlikely hypothesis actually has stronger evidence. It looks as if the waving is more effective strategy than the other strategy. So we just this; we gave four year-olds this pattern of evidence, and just asked them to make it go. And sure enough, four year-olds used the evidence to wave the object on top of detector.
Now there are two things that are really interesting about this. first one is, again, remember, these are four year-olds. They’re learning how to count. But unconsciously, they’re doing these quite complicated calculations that give them a conditional probability measure. And the other interesting thing is that they’re using that to get to an idea, get to a hypothesis about the world, that seems very to begin with. And in studies we’ve just been in my lab, similar studies, we’ve show that four year-olds are actually at finding out an unlikely hypothesis than adults are we give them exactly the same task. So in these circumstances, children are using statistics to find out about the world, after all, scientists also do experiments, and we wanted to see if children are experiments. When children do experiments we call it “getting into everything” or else “playing.”
And there’s been bunch of interesting studies recently that have shown this playing around is a kind of experimental research program. Here’s one from Legare’s lab. What Cristine did was use our Blicket Detectors. what she did was show children that yellow ones made it and red ones 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 two minutes.
(Video) Boy: How about this? Same as other side.
Alison Gopnik: Okay, so his first hypothesis just been 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 recognize that 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 is his idea. He told the experimenter to do this, to try putting it out onto the location. Not working either.
Boy: Oh, because the light only to here, not here. Oh, the bottom of this has electricity in here, but this doesn’t have electricity.
AG: Okay, that’s fourth hypothesis.
Boy: It’s lighting up. So when you put four. So you put four on this to make it light up and two on this to make it light up.
AG: Okay,there’s his fifth hypothesis.
Now that is particularly — that is a particularly adorable and articulate little boy, but Cristine discovered is this is actually quite typical. If you look at the way children play, when ask them to explain something, what they really do do a series of experiments. This is actually pretty typical of year-olds.
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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 in minutes? Well, if you go back to those psychologists and philosophers, lot of them have said that babies and young children were barely conscious if they were conscious all. And I think just the opposite is true. think babies and children are actually more conscious than we as adults. Now here’s what we know about how consciousness works. And adults’ attention and consciousness look kind of like a spotlight. what happens for adults is we decide that something’s relevant or important, we pay attention to it. Our consciousness of that thing that we’re attending to becomes extremely bright vivid, and everything else sort of goes dark. And we know something about the way the brain does this.
So what when we pay attention is that the prefrontal cortex, the sort of part of our brains, sends a signal that makes a little part our brain much more flexible, more plastic, better at learning, shuts down activity in all the rest of our brains. we have a very focused, purpose-driven kind of attention. If we look at babies and young children, see something very different. I think babies and young seem to have more of a lantern of consciousness than a spotlight of consciousness. So babies young children are very bad at narrowing down to just one thing. But they’re very good at in lots of information from lots of different sources at once. And if you actually look 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 yet. So when we say that babies and young are bad at paying attention, what we really mean is that they’re bad at paying attention. So they’re bad at getting rid of all the interesting things 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 expect from those who are designed to learn.
Well if we want to think about a way of getting taste of that kind of baby consciousness as adults, I think best thing is think about cases where we’re put in a situation that we’ve never been in before — when we fall in love with someone new, when we’re in a new city for the first time. And what happens then is that our consciousness contracts, it expands, so that those three in Paris seem to be more full of consciousness and experience than all the months of 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 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 way be, but it does tend to leave you waking up crying three o’clock in the morning.
(Laughter)
Now it’s good be a grownup. I don’t want to say too much about wonderful babies are. It’s good to be a grownup. We do things like tie our shoelaces and cross the street by ourselves. And it sense that we put a lot of effort into making babies think adults do. But if what we want is to be like those butterflies, have open-mindedness, open learning, imagination, creativity, innovation, maybe at least of the time we should be getting the adults to thinking more like children.
(Applause)