ALAN ALDA (NARRATION) I’m visiting a lab Harvard University that conducts ingenious experiments to find out what children know and what they don’t. And right away I’m in for a surprise.

ALAN ALDA We are trying to figure out the Human Spark, what makes us human, and we certainly do seem to be very different from the other animals.

ELIZABETH SPELKE To say the least…

ALAN ALDA So are we born with something that right off the bat that make us vastly different?

ELIZABETH SPELKE I don’t think so. This is a question that I’ve been trying to answer for the last 30 years or so, and for most of that time, my hunch was that we were, that we would see in infants systems of knowledge that human infants alone would display. But when we look hard at what a four month old or six month old infant can do, we see very close similarities between the capacities of human infants and the capacities of infants and adults of other species. So I don’t think that that Human Spark ignites early in development.

ALAN ALDA What would bring it about, are we very reliant on this culture that we have?

ELIZABETH SPELKE I think that’s a great question, and one that’s very debated right now. My personal view is that what’s most central to the sparking of uniquely human cognitive capacities is our capacity for language, and its when children really get going on the task of learning language, learning their first words at 9 or 10 months of age, putting words together a few months later, that’s when we start seeing these uniquely human capacities emerging.

ALAN ALDA (NARRATION) So Liz Spelke sees language as igniting the Human Spark. She’s exploring that idea by studying how language allows children to interpret maps as representing the real world.

ELIZABETH SPELKE So you take a 2 1/2 year old child and show them a two-dimensional drawing that simply has a simple geometric figure on it, say a triangle, and say to them:

NATHAN WINKLER-RHOADES Nora, guess what. Kermit. He has a favorite bucket that he likes to sit in. There is one bucket that he likes the best, and today we are going to put him in his favorite bucket, OK? Here’s our picture of the room. There’s one bucket, there’s another bucket and there’s another bucket. Kermit, which one is your favorite bucket? “My favorite is this one, right here.” Oh, Kermit said that this one is his favorite. Nora, can you put Kermit in his favorite bucket? Yay!

ELIZABETH SPELKE That’s a remarkable ability. But if you ask what you have done with this child to engage this ability, to engage this symbolic function, you have talked to them, you told them…

NATHAN WINKLER-RHOADES There’s one bucket, there’s another bucket and there’s another bucket…

ELIZABETH SPELKE And that raised the question, what if you didn’t do that? What if you simply showed them the piece of paper and said:

NATHAN WINKLER-RHOADES There’s one, and there’s another, and there’s another. Now, Kermit, which is your favorite one? “My favorite one is this one, right here.”

ALAN ALDA (NARRATION) Notice that unlike Nora, Xander isn’t told that the spot on the map represents a bucket.

NATHAN WINKLER-RHOADES Can you put him in his favorite bucket? Yay, good job. You got him on the picture. We want to get Kermit in his favorite bucket in the room. Which is Kermit’s favorite bucket?

ALAN ALDA (NARRATION) Without the cue of language, Xander wasn’t able to relate the map to real world. But when he’s prompted…

ALAN ALDA And they have this ability, you think, because they’re already manipulating symbols in language.

ELIZABETH SPELKE Exactly, exactly. And as far as I can see, that ability develops spontaneously in us by virtue of being human. It doesn’t develop at birth, we don’t see it until children are about 9 or 10 months of age, but as far as I can see that’s an innate, uniquely human capacity that emerges in children toward the end of the first year.

ALAN ALDA (NARRATION) For Liz Spelke the key to both human language – and the Human Spark – is the ability to manipulate symbols in our minds… an innate ability, but one that doesn’t kick in until we’re almost a year old.

To find out just how our language skills develop in childhood, I’ve come here to the University of Oregon.

ALAN ALDA Do you think you can figure out what there is about us that enables us to talk to one another?

HELEN NEVILLE The first thing that you learn as a child is just the sounds. Babble babble. And then at about a year they start learning that words stand for objects in the world, usually nouns is what they start with. So they’ll say, “ball, cat.” And then they later they’ll get some verbs, “eat.” And then only at about a year and a half will they start making little sentences, put two words together like, “Mommy up.”

ALAN ALDA I have a grandson, his first two-word sentence was “eat out.”

ALAN ALDA (NARRATION) Helen is figuring out how we get from sounds to sentences with the aid of what must be the world’s most attractive headgear.

HELEN NEVILLE That is a lovely hat, the color really suits you.

ALAN ALDA I don’t know why these never caught on. Let me ask you about the difference between us and other animals. If I say to a well-trained dog, “Get me the bone,” he’s liable to be able to do it. But if I say to him, “Get me the bone that’s behind the door,” he might have trouble with that. Right? Because there are too many ins and outs in that sentence. Is that a big difference between us, or is that bridgeable with other animals?

HELEN NEVILLE Well, I think that just about everybody agrees that that’s the main difference between human communication or human language and other animal communication systems. Is that other animals can have visual symbols or even sound symbols can stand for particular objects in the world. That’s right, like my dog knows the meaning of several words. “Car”: we’re going in the car. Or “bone,” “Cookie, you want a cookie.”

ALAN ALDA Cookie, yeah. I know all these too you know. So far I’m right up with your dog there. But when does the dog have trouble?

HELEN NEVILLE Well, if you were to say, “I want you to get the cookie that is followed by the car” versus…

ALAN ALDA Or the cookie that’s in the car, he’d think, “we’re gonna go for a ride and where’s my cookie?”

HELEN NEVILLE Yeah, it’s all good. That’s right. So, that’s the main difference between human language and animal communication systems, is grammar. I think everybody agrees about that.

ALAN ALDA (NARRATION) So, grammar is what makes human language critical to igniting the Human Spark. Which is where my new hat comes in. It’s going to be checking out my grammatical skills while I watch a video.

ALAN ALDA I just have to watch it. These electrodes are picking up what I’m thinking.

RESEARCHER: Yeah, we see a brain reaction within a hundred milliseconds, whether you’re doing a task or not actually.

ALAN ALDA (NARRATION) The video’s narration sometimes makes sense…

PINGU A baby penguin swings on that door.

ALAN ALDA (NARRATION) And sometimes it doesn’t…

PINGU The truck goes up and down in the papers over hills.

ALAN ALDA (NARRATION) The electrodes are recording where and when my brain reacts to these mistakes. When the mistake is simply a word that doesn’t make sense…

PINGU Pingu turns up the penguin really loud. ALAN ALDA (NARRATION) An area in the back of my brain, mostly on the left, reacts within two tenths of a second. But when the mistake is grammatical…

PINGU The concert are starting.

ALAN ALDA (NARRATION) My brain pounces on the error within one tenth of a second, and this time in a region toward the front and exclusively on the left.

Following me into the video booth, and equipped with a much more fetching hat, is six-year-old Donica. When there’s a mistake of meaning…

PINGU Pingu claps her ball happily.

ALAN ALDA (NARRATION) Her brain, just like mine, reacts in two-tenths of a second. But when the video says something grammatically incorrect…

PINGU The pancake falls onto their his head.

ALAN ALDA (NARRATION) Her brain is slower to respond than mine, and the response isn’t so focused over that area in the front left. In fact, Helen Neville argues, it takes perhaps ten or fifteen years for the brain to organize itself to process grammar swiftly and efficiently in just one focused, specialized region.

HELEN NEVILLE It looks for example like that’s an important area for sequencing different kinds of information and of course sequencing is an important part of language. It looks like areas just behind there are very important for tool use in the left side as well.

ALAN ALDA Tool use?

HELEN NEVILLE Tool use, yeah.

ALAN ALDA Tool use over where language is taking place?

HELEN NEVILLE Actually, it’s possible that one aspect of language is closely tied to tool use, especially this kind of action planning and sequencing that we have to do in order to talk.

ALAN ALDA (NARRATION) Now this is a fascinating take on the Human Spark – that two of the most defining attributes of what makes us human – language, and the making and using of tools – should somehow be tied together in our brains. What makes it even more fascinating is that I’d heard this idea before – in a very different context.

JOHN SHEA Good, yeah, you’re getting the hang of this.

ALAN ALDA (NARRATION) While searching for the first glimmerings of the Spark in our ancestors, I had joined a class in stone-age technology run by John Shea at Stony Brook University. I was able to put a pretty effective cutting edge on a piece of rock…

ALAN ALDA It’s very sharp, yeah….

ALAN ALDA (NARRATION) But a key moment in human evolution, a moment many anthropologists believe the Human Spark first ignited, is when humans went from making simple stone tools to combining smaller, finer stone points with other materials to make spears and arrows.

JOHN SHEA It’s possible that the combination of different elements is paralleling linguistic structure, where meaning comes from recombining different elements and different orders. And just as there is only one proper, or a limited number of proper ways to say the sentence I’m saying right now, there’s only a few proper and effective ways to combine these elements of stone and string and wood. And if you do it the wrong way, you’re dead. Natural selection, you know!

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