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Can Chips Talks ?

Transcript extracted from the newsgroup "jrnl.pbs.nova" on 19 Feb 1994.

This transcript is provided as a service of Journal Graphics. The WGBH Educational Foundation is not responsible for any errors or mischaracterizations in this transcript. This transcript has not been proofread against the videotape and the producer's records and its accuracy cannot be guaranteed. (JPM).

ANNOUNCER:  Tonight on Nova, a chimpanzee called Kanzi seems to understand human speech to a degree never before thought possible.

SUE SAVAGE-RUMBAUGH, Georgia State University:  Parents really don't know how they teach their children language. Why should I have to know how I teach Kanzi language ? I just act normal around him, and he learns it.

ANNOUNCER:  The capacity for language was long thought to be exclusively ours, but some remarkable apes caused us to ask, `Can Chimps Talk?'

JANINE MURPHY [sp?]:  Kanzi, this is Janine. Would you like any food ? Tell me what food you'd like.

TALKING KEYBOARD:  Food surprise.

Ms. MURPHY:  Some food surprise?

TALKING KEYBOARD:  Food surprise.
Ms. MURPHY:  Kanzi, would you like a juice, or some M&Ms, or some sugar cane?


Ms. MURPHY:  You like M&Ms? Okay. Kanzi, is there any other food you'd like me to bring in the backpack?


Ms. MURPHY:  A ball? Okay.

NARRATOR:  [voice-over] This conversation is the first time that the chimp Kanzi has ever spoken on the telephone, using his talking keyboard.
On the other end of the phone was Janine Murphy. It was a conversation with someone not physically present, about events yet to take place. It's not the kind of thing which scientists thought chimpanzees could do.

SUE SAVAGE-RUMBAUGH, Georgia State University:  In looking at what Kanzi can do, the kinds of utterances that he can emit without any specific training, the kinds of really complex sentences that he can understand without any training, make one suspect that in apes now, and certainly in early hominids, there was a capacity for some form of primitive language.

NARRATOR:  [voice-over] The idea that apes and humans might share a common potential for language radically undermines the view that there is a strict divide between humans and the animal world. Kanzi is a bonobo [sp?], a rare chimpanzee species, and the latest in a long line of apes to be used by scientists to study language.
Dr. SAVAGE-RUMBAUGH:  You want to help get some sticks? Good. I have a lighter in my pocket, if you need one. You can get it out. 
[to interviewer] There's a lot of discomfort in accepting the fact that apes really have language. Kanzi's ability to understand suggests to me that if he had a human vocal tract, he would be talking.

NARRATOR:  [voice-over] This is probably the strongest claim ever made for the linguistic capacity of a chimpanzee.

Dr. SAVAGE-RUMBAUGH:  Kanzi, I need you to break this stick for Sue, please.
[to interviewer] We, as human beings, have always considered language our own domain, in that it is innate.

NARRATOR:  [voice-over] Most current theories of linguistics assume that only humans can acquire language.

Dr. SAVAGE-RUMBAUGH:  You've got to put some water on the fire. Do you see the water?

NARRATOR:  [voice-over] Only humans are thought to have a brain specially evolved to decode the complex rules of grammar.


NARRATOR:  [voice-over] Now, Kanzi's abilities are forcing scientists to reexamine this fundamental idea. Experiments to discover whether apes could acquire some form of human communication have created an academic storm which has raged for decades. One of the most famous and controversial attempts began nearly 30 years ago, in Reno, Nevada.

ALLEN GARDNER, University of Nevada:  On June 21st, 1966, an infant chimpanzee arrived in our laboratory. We named her Washoe, for Washoe County, the home of the University of Nevada. Because she was captured wild in Africa, we will never know just where or when Washoe was born, but we estimate that she was about 10 months old when she arrived in Reno.

NARRATOR:  [voice-over] Because chimps' vocal apparatus don't allow them to make the sounds of human speech, psychologists Allen and Trixie Gardner decided to teach Washoe American sign language, used by the deaf. To help Washoe learn her signs, they used many techniques, including fun and familiar games, repeated over and over again.

BEATRIX GARDNER, University of Nevada:  The first sign that we did indeed teach to Washoe was the sign for more. More. More. More. More.

NARRATOR:  [voice-over] Natural chimpanzee gestures provided the basis for some signs.

Ms. GARDNER:  Come. Open. Open hurry. Open. Open hurry. Open hurry.  Open. Open. Open. Good, good, good me. Yes, you're very good. Good go. Good go. Where? You peekaboo. Out me. Open. Hide. Peekaboo. Okay. Come good Washoe, come with me.

NARRATOR:  [voice-over] The Gardners reported that Washoe could eventually use 133 signs.

Ms. GARDNER:  Good Washoe and I are going to go.

NARRATOR:  [voice-over] By then, Washoe was five years old.

Ms. GARDNER:  Good me.

NARRATOR:  [voice-over] Altogether, the Gardners collected more than 20 years of data. Their research covered all aspects of chimp development, but it was the experiments in sign language which caught the imagination of scientists and public alike. For the first time, an ape was using human language, as these films clearly showed. But instead of sealing the ape language debate, these images were to become the focus for a bitter dispute.
In this sequence from 1974, Washoe is shown a baby doll inside a cup. The camera seems to capture clear evidence of a chimpanzee sentence, `Baby in my drink.' The problems began when another chimp began his career as a language student, commuting daily to Columbia University in New York. 
The researcher, Herb Terrace [sp?], was trying to replicate the Gardner study using his own ape, called Nim Chimsky. The name was a lighthearted dig at linguist Noam Chomsky, who believed language ability was confined to the human species. Terrace hoped to teach Nim to assemble signs into sentences, using the rules of grammar, but the experiment did not turn out quite as Terrace planned.

HERB TERRACE:  The main goal of Project Nim was to ask whether a chimpanzee could create a sentence. I have concluded that, unfortunately, the answer to that question is no.

NARRATOR:  [voice-over] In this example, Nim seems to be using a combination of signs to ask if he can hug the cat, but Terrace argued that he was not actually making a sentence. By freezing the tape, you can see that first the trainer makes the sign for hug, and just a few frames later, Nim copies her. Next, the trainer signs cat, and shortly after, so does Nim. Terrace concluded that chimps cannot produce language, they can just imitate their trainers. Terrace also looked at some of the Gardners' films. He decided that Washoe, too, was being led by her teacher. The Gardners disagreed, and attacked Terrace's methodology.

Mr. GARDNER:  Well, Herb Terrace set out to prove that if you use Skinnerian reinforcement you could teach a chimpanzee syntax. It was an entirely different objective from ours. And when he failed, he declared
that everybody had failed.

NARRATOR:  [voice-over] The Gardners also point out that in the disputed example, Washoe's signs are quite different from her teacher's, and so can't possibly be imitation. Susan is asking, `What that?' and Washoe answers, `Baby in my drink.' This, they say, was a typical conversation, and was interesting because of its similarity to ordinary conversations between adults and young children.

Mr. GARDNER:  What we were interested in is not whether it fitted some abstract theory of linguistics, but whether the chimpanzees could actually communicate information to us, things we didn't already know.

NARRATOR:  [voice-over] The Gardners continued their experiments with four more chimps who, like Washoe, were all brought up as human children. 
They tested their ability to communicate under controlled, double-blind conditions. The chimp could see an image on the screen, but the experimenter could not. Two independent observers had to agree for the sign to be marked correct. The chimps showed reliable and consistent signing. They had vocabularies above 100 signs, and each used them in their own
individual ways.

Ms. GARDNER:  Tatu, unlike the others, had black as her very favorite color. We would go through magazines, looking for black things, and she would go around naming black things for you. `That's black, and that's black, and that is black.' And sometimes you could even tease her about that. You'd go through a magazine and she'd point at it, at a picture, and
give you eye-to-eye contact - the question, `What is that?' - and for a while, you played her game and you said, `It's black, it's black,' using her favorite sign. But then you'd tease her and say it was red, and of course she would correct you right away and say, `It's black. That's black.' It's a very nice conversational use of sign language. She knew the answer, but she wanted you to talk about that.

NARRATOR:  [voice-over] But the arguments over ape language persisted.

PATRICIA MARKS GREENFIELD, UCLA:  I think that there are a lot of people who are very worried about us finding a relationship between humans and animals, and they want there to be an absolute dividing line. What Terrace did was again to say, `Yes, there is a line,' and I think people responded very emotionally. And instead of it just being another point of view where it would be interesting to do further research and see who was right, Terrace or the people who had done the early work, such as the Gardners, the whole field just closed down.

NARRATOR:  [voice-over] Eventually, the Gardners' funding ran out, and their chimps were moved to another university. The early dreams of rearing them to adolescence and beyond were never fulfilled. While the eight researchers were battling over Washoe, Nim and definitions of language, Patricia Greenfield was taking a fresh look at how human children use their
first words. If apes were a species on the threshold of developing language, it seemed logical to compare them with a child at a similar point. Her subjects were even closer to home. She studied her own children, Matthew and Lauren. Here is Matthew with his mother now, and this is Matthew, captured on film at the age of two as part of the study.

Ms. GREENFIELD:  I knew all about the Chomskyan approach to child language development, which is an approach in which grammar is very central, and the child is considered sort of like a little grammar machine, or becoming a big grammar machine. And when my daughter Lauren started to speak, what absolutely hit me was that this was not- what she was doing was nothing like what they were describing. And in fact, what they were describing were children combining words with words, using rules, but what she was doing when she first started to talk was combining words with things, with people, with gesture, all sorts of nonverbal elements. Do you want another piece of cheese ?


NARRATOR:  [voice-over] Greenfield showed that these verbal and nonverbal elements had a grammar of their own. This was the foundation on which full-blown language would be built.

Ms. GREENFIELD:  Would you like some potato ?

LAUREN:  Open.

Ms. GREENFIELD:  But that approach was very unpopular, and was very heavily criticized, I think to a large extent because of the bias that words are realer than these nonverbal elements, and that if somebody expresses something in a word, you know it was really there.

NARRATOR:  [voice-over] Greenfield, too, looked at the Gardners' films and saw that their chimps combined word signs with gestures to get their meaning across. This could be the same precursor to language as she had seen in children.

Ms. GREENFIELD:  Children can do something and it's called language. Say a two-year-old does something, the researcher calls it child language. A chimpanzee does the same thing, and it's not language. And I think the reason is, there's a double standard, and what the double standard comes from is the fact that we all know that children will ultimately grow up and speak full-blown human language. We also know that chimpanzees will not grow up and ultimately speak or produce full-blown human language, and so there's a bias in the interpretation of the data.

NARRATOR:  [voice-over] One attempt at getting data free from bias involved Lana. Instead of sign language, she was given a computer keyboard, with symbols to represent words. The keys she pressed were automatically recorded, so there could be no argument over what she had said.

DUANE RUMBAUGH, Georgia State University:  The keys were made of plastic. They were backlighted, and when they were touched they gained an additional level of brilliance. Then a facsimile of the lexagram on the surface of the key was produced in one of the projectors in a row above her keyboard, and thus she was able to produce a string of lexagrams, if you would, a primitive sentence. So this was the idea that launched the Lana project and the idea which, in fact, has carried the research project with chimpanzees and also with children across the time span now of better than 20 years.

NARRATOR:  [voice-over] Duane Rumbaugh's computer technology and Sue Savage-Rumbaugh's experience with signing chimpanzees led to a formidable alliance which has given ape language research a fresh start. Here in Atlanta, Sue Savage-Rumbaugh also had access to a different species of chimpanzee. Previous research used the common chimpanzee, but she was attracted by a number of differences found in the bonobo.

Dr. SAVAGE-RUMBAUGH:  This species is very, very rare and endangered, found only in a small area of Zaire, and was only identified as a separate species in 1929. They differ from the so-called common chimpanzee in a number of ways. First of all, they have very stable large social groups in which there are strong ties between males and females. They have a very,
very low level of aggression, and the society seems organized around caring for young bonobos. Subjectively, it has an extraordinarily different feel from other chimpanzees. The facial expressions of bonobos are much more humanlike. The vocalizations of bonobos are much more frequent and much higher-pitched. Common chimpanzees, although very wonderful creatures are, compared to the bonobo, somewhat stand-offish. The bonobos like physical contact, they like to be around people. Kanzi's mother, who was a wild-caught bonobo, is one of my very best friends.

NARRATOR:  [voice-over] Matada [sp?] was also the starting point for what has been described as a groundbreaking project, to establish just how well a chimpanzee can develop a competence with human language.

Dr. SAVAGE-RUMBAUGH:  We began with Matada, and she was not a very adept pupil. Matada seemed to have many ways of communicating. She would lead me around by the hand, she would vocalize, she would look off in the distance and vocalize and gesture to me, and I had no question but what she was trying to communicate with me. But she seemed to think lexagrams were a rather ridiculous method of communication.

NARRATOR:  [voice-over] But while Matada wasn't learning, her son Kanzi very rapidly caught on to the possibilities of the keyboard when he was only a few months old. He learned that each abstract symbol on the board meant something. Here, he pressed `bite.' What he wanted was a bite of what Sue had in her mouth. His use of symbols was the equivalent of a young child using single words.
Ten years later, Kanzi easily identifies words spoken by complete strangers, and can echo them by pressing the correct key on the lexagram board, which now talks.

TALKING KEYBOARD:  Potato. Shoe. Give.

Dr. SAVAGE-RUMBAUGH:  The most exciting thing with Kanzi was that he began to use this keyboard very, very frequently. He clearly helped us understand that he knew what those symbols meant. For example, if Kanzi said something like, `Chase apple,' he then would go over and pick up the apple and start running away, and look back at me, showing me behaviorally that he knew what he had said, and gauging me.
When I first found out that Kanzi was learning language without any attempt on my part to really teach him, it was just as we were coming up for funding renewal. Kanzi was about three or three and a half years of age, and the site visitors kept asking me, `Well, we understand that Kanzi's doing this, we've seen him do it, we hear you say that he's learning how to understand words in some sentences, but how is he doing it ?
How did you teach him to do it? How did you get him to do it ?' And I was at a complete loss. I said, `Well, parents really don't know how they teach their children language. Why should I have to know how I teach Kanzi language? I just act normal around him and he learns it. I don't really know what's going on in his head.' But they made me realize that, unlike a parent, as a scientist I really had an obligation to figure out how this was happening. 

Kanzi was an ape, not a child, and so I wanted to construct some kind of environment that would make the usage of language real for Kanzi. And I asked myself, `Well, what do apes do in the wild?' Well, everyone knows they travel around to different places and they find food and they eat it, so I decided, because we had 55 acres of forest, to have certain feeding areas, and to spend Kanzi's days traveling from place to place, talking about where we were going to go, what kind of food we were going to eat, and what we were going to do next.

NARRATOR:  [voice-over] The experiment continued with Kanzi's sister, and everyday use of English language.

RESEARCH ASSISTANT:  Panbenisha, will you do something for Sue ?

Dr. SAVAGE-RUMBAUGH:  And then you'll chase her.

RESEARCH ASSISTANT:  And then I'll chase you.


Dr. SAVAGE-RUMBAUGH:  Tell her yes, you'll chase her, but you want her to do something for me later on.

RESEARCH ASSISTANT:  And I want you to do something for Sue.

Dr. SAVAGE-RUMBAUGH:  Now, we're going to do some things, and then Ryan will chase you, okay, Panbenisha? Could you throw the kiwi? Good job, good job. Thank you. You can have some jelly, it's all right. Let's go chase, Ryan.

Dr. SAVAGE-RUMBAUGH:  What we have begun to learn is that chimpanzees and, I suspect as well, children have an intrinsic desire to try to figure out what's going to happen to them next. They would like their world to be predictable, whether they're going for a walk in the woods, whether they're going down to visit the river. They'd sort of like to know, when they're very young, in particular, what everybody is going to do next. And so, because they really want to know this, there's an intrinsic desire to figure out what the language is about.

Dr. SAVAGE-RUMBAUGH:  I've got the onions in a bowl. Let's go put them in our hot food and we'll come back and turn the TV on. Put your onions right here and put them in your bowl. Look, you spilled some of them.

NARRATOR:  [voice-over] The chimps have responded well to such a rich environment, and show an unprecedented grasp of spoken English.

Dr. SAVAGE-RUMBAUGH:  Let me get you a spoon to stir it with, Kanzi.

NARRATOR:  [voice-over] In addition to spoken language, they receive a steady stream of nonverbal cues, attention-directing maneuvers, and repetition, the hallmarks of the way we speak to young children.

Dr. SAVAGE-RUMBAUGH:  Here, will you wash this potato off for me ? Could you wash the potato ?

NARRATOR:  [voice-over] Sue Savage-Rumbaugh is convinced that the combination of all these everyday interactions at an early age is essential for the acquisition of language. Scientists call this process enculturation.

Dr. SAVAGE-RUMBAUGH:  All right. Your noodles are going to go in here, and you can have a few of them for your tummy. Kanzi, could you turn the water off again, please? Turn the water off, please.

NARRATOR:  [voice-over] In the kitchen, in Sue's company, Kanzi functions impressively. But does Kanzi, like a human, really have the ability to understand words? He can match spoken words with lexagrams, but what do they mean to him? Can he make the connection between words and things in the real world under test conditions ? A set of 16 photographs has been selected from the several hundred which represent the nouns in his vocabulary.

Dr. SAVAGE-RUMBAUGH:  Okay, here's your pictures. Here's your pictures. Watch now, they're coming around. All right. Kanzi, see if you can find mushrooms. Mushrooms. That's right, those are the mushrooms. Real good. Can you turn back around ? Okay. Now, now- okay, you're doing real good, Kanzi. See if you can find Mardu [sp?] the orangutan. Do you see Mardu? Good job. Good job. See if you can find some melon. Melon. Melon. Thank you.

NARRATOR:  [voice-over] Kanzi consistently scores better than 90 percent with such sets of pictures. A more rigorous test involves Kanzi wearing headphones, so only he can hear which picture is being requested.

RESEARCH ASSISTANT:  Kanzi, give Sue bananas. That's right. Kanzi, give Sue ice. That's right. Kanzi, give Sue pears. That's right. Kanzi, give Sue potatoes.

NARRATOR:  [voice-over] The tests on single words are convincing, but how does Kanzi deal with words in combination? How do researchers know that he is not just doing the most obvious thing, given the range of possibilities available to him? One of the hallmarks of human language is its creativity, the possibility of expressing an infinite number of ideas. We can understand the meaning of a sentence even if we have never heard its words in that particular order ever before. Dr. Savage-Rumbaugh set out to test whether the same applied to Kanzi. There were 600 sentences in all, designed to use different grammatical forms and to be as unpredictable as possible.

Dr. SAVAGE-RUMBAUGH:  Give the doggie a shot. Good job. Put the keys in the refrigerator. Good job. Thank you. Very nice. Okay. Go get the ball that's outdoors.

NARRATOR:  [voice-over] To do this, Kanzi has to ignore another ball which is indoors. That Kanzi could comprehend and carry out such instructions is interesting enough, but Dr. Savage-Rumbaugh went a step further. How did Kanzi's understanding of language compare with that of human children? Janine Murphy volunteered her daughter, Alea [sp?], to take part in an identical study at the age of two years. On some sentence types, Kanzi excelled; on others the child did better. But by and large, both were correct about three-quarters of the time. So far as comprehension went, child and chimp were on a par.

Dr. SAVAGE-RUMBAUGH:  Could you take my shoe off, please? You might need to untie it.

NARRATOR:  [voice-over] For both child and chimp, the ability to understand outstripped their ability to produce language, the girl because of her age, and Kanzi because the chimpanzee vocal tract does not allow it. 

Dr. SAVAGE-RUMBAUGH:  :  Now you can take it off. It will come off now. 

Mr. SAVAGE:  It is in what an individual comprehends that we use as the basis for saying that individual is language-competent. If they can't speak because of some anatomic reason, we don't say, well, they don't have language. We say that they can't speak and they need some other kind of medium for that.

TALKING KEYBOARD:  Want milk. Milk.

Dr. SAVAGE-RUMBAUGH:  You want some milk? I know, you always want some milk when you're planning to be good.

TALKING KEYBOARD:  Key. Matada. Good.

Dr. SAVAGE-RUMBAUGH:  Oh, you want the key to Matada, and you're going to be good. Well, I'm glad to hear that. I'm glad to hear that.

Dr. SAVAGE-RUMBAUGH:  For a long time, it was thought that only the human brain could understand human speech. Now we know that Kanzi's brain can understand human speech, which says very clearly that something important happened in our evolution. Our brains were able to understand speech, and suddenly our mouths became able to produce speech.

NARRATOR:  [voice-over] The sudden emergence of speech from a hominid, which hitherto had, like the ape, only a potential for language, may be linked with our unique anatomy.

Dr. SAVAGE-RUMBAUGH:  I suspect that there's something very, very unique about the human bipedal posture and the human vocal laryngeal apparatus. One of the things that we know it enables us to do is make sounds like ga and ba and pa and da, sounds that we call consonants. Kanzi can't make these kinds of sounds. His sounds are mostly vowel sounds. And
if I try to talk to another person using only vowel sounds, they can't understand me.

NARRATOR:  [voice-over] Kanzi often tries to copy human speech, but analysis of the voiceprints of human and bonobo shows the problem. The human print shows the boundaries of the words clearly, where Kanzi's are blurred.

Dr. SAVAGE-RUMBAUGH:  We tried to invent a language for Kanzi that was composed only of vowel sounds, and we couldn't understand ourselves, which tells you what consonants do for us. They wrap little packages around vowel sounds. They are like edges around vowel sounds, and they help us tell our words apart, where one word stops and another word starts. And because we could do that, we could invent languages. We could utter new sounds that were discriminably different. We could go around and name all kinds of things with words that sounded different to other individuals. And I think this must have been a great turning point in the evolution of mankind. And I think if you could give chimpanzees or bonobos that same ability today, they would take off and they might follow a course that would be eerily similar to that of our own species.

NARRATOR:  [voice-over] Research in areas other than language is showing similar results. In Columbus, Ohio, Sarah Boyson is exploring the way chimps handle numbers, and is finding capabilities never before suspected.

SARAH BOYSON, Ohio State University:  Can you bring me one just like this ? That's the right one, huh-huh. It's just like that, isn't it ? This here is a little gumdrop. That was good.

NARRATOR:  [voice-over] Sarah Boyson previously worked with Sue Savage-Rumbaugh. She uses nursery style methods of education with her chimps to encourage the development of mathematical skills. Bobby is five years old. In the wild, he would still be very dependent on his mother, and only just weaned.

Ms. BOYSON:  Like that? No, they don't look alike. They don't look alike.

NARRATOR:  [voice-over] As with children, it takes patience and repetition to convey key concepts.

Ms. BOYSON:  This one looks like that one. Oh-oh. That looks like this. That has a mat. You are doing such a good job today. Look, here a red gumdrop and a yellow jellybean, just for you. That's right, two things, one, two things.

NARRATOR:  [voice-over] Bobby is learning to identify numbers of things with Arabic numerals.

Ms. BOYSON:  One, you have to watch, one, two, three, four.

NARRATOR:  [voice-over] Using his touch screen, Bobby is able to clearly indicate his choices. Technology is combined with essential human contact.

Ms. BOYSON:  Similar to a child, you have to create a loving environment in order to have a healthy, confident child. You have to create a similar kind of relationship with a chimpanzee in order to have a healthy, happy, confident chimpanzee student. What that buys you, when they are a little older, is a willingness to negotiate and to persist at a task when otherwise they might not be so excited about working further that day. 

[to chimp] You ready for your [unintelligible] already? Okay. Now, watch what I'm going to do. I'm going to put a banana here, but look. How much banana's left? A half of a banana, that's right. A half a banana is left. And you get that. Oh, you want two things? No, I'm not giving you two things. You just wait.

NARRATOR:  [voice-over] Using this approach, Boyson has demonstrated in her chimpanzees some fairly sophisticated capabilities with numbers.

Ms. BOYSON:  Two, that's right. It's two oranges. Look, I have two orange things for you, two orange jellybeans. This is ready. Yeah. Okay. Now, look, I've got a half a banana here. Right here's a half. But watch what I'm going to do with it. I'm going to only take part of a half. Look there, I just have a little piece left. It's one-fourth. That's right, one-fourth. Do you want that one-fourth? Okay.

NARRATOR:  [voice-over] These chimps are able to extend their capabilities beyond the tasks in which they were acquired. In one particular experiment, Sheba exceeded all expectations.

Ms. BOYSON:  Very good. Okay. 
[to interviewer] Sheba's goal was to move from place to place, pay attention to how many oranges were there, come back to a starting location where her numbers were displayed, and pick the answer that stood for the total number of oranges that were hidden.
[to chimp] Are you paying attention? Let's try a real easy one. All you have to do is remember. Yeah, okay. How many would you call that? How many is that? How many oranges were in your bin, Shebe? Can you try and show me? Four. Right. Have some candy. Go ahead. No, you can have some candy. Oh, you got four candies out, too. That was very nice. And you've never done that before.
[to interviewer] Now, remember, this is a task I thought she could eventually learn. What we discovered, much to our surprise, was that the very first time Sheba had the opportunity to do that, to go look at different amounts of oranges in different places, she was able to give us the total. How- how did she learn to do this when all we thought we taught her to do was to associate Arabic numerals with quantities? Clearly, some way out of that experience with simple counting, or simple association, if you will, came an emergent capability.
[to chimp] Bob, we're about to start. I need your cooperation. Thank you very much.

NARRATOR:  [voice-over] The next test exploits the fact that a chimp confronted by two piles of candy will automatically choose the larger one. The question is, can their behavior be changed by learning the rules of the game ?

Ms. BOYSON:  Good, here we go. We'll do another turn. All right. This time we'll put this many here, and we'll put this many here. See which- oh, you want to pick these first. Okay, well, we'll have to give these six to Bobby. Sheba gets three and Bobby's happy.

NARRATOR:  [voice-over] The animals are given a choice between two different amounts of candy, and the rule is simple. If you pick an amount, it goes to your partner, and you get whatever is left over. That's it. That's the rule.

Ms. BOYSON:  Okay. One here. Sheba, which one's for Bob? Point. Oh, Bob gets two. Good. All right. There you go. See, you get that one.
[to interviewer] So if you are aware of the rule, then in order to get the most, the first amount you should pick should be the smallest amount, right? Because then you get the biggest remainder.
[to chimp] I'm going to put this many here and this many here. Which shall we give away? Oh, we're going to give away these. All right. All right. Bob gets four, and Sheba only gets two.
[to interviewer] They don't get it. They can't do it. They can't inhibit selecting the larger array immediately. And so even though it might be very distressing, as soon as they do it they understand, `Oh, no, I did it again. She's going to get more than me.' And as we explored further, it occurred to us to try to substitute the numbers of candies with numbers. 
[to chimp] Two for Bob.
[to interviewer] From the moment that occurred, the rules unfolded as you would expect.
[to chimp] Which one are you going to pick, this one or this one ? Now give it to Bobby. You're going to pick two. Okay. We broke that up.
[to interviewer] And you could literally shift from trial to trial, numbers, candy, candy, numbers, and her performance would go up and down.
[to chimp] Well, how about if you could choose between this and this ? Bob should get three. Okay. We'll give three to Bob. You're happy, aren't you? One, two, three for Bobby. And Sheba, you get six.
[to interviewer] The introduction of the numbers completely releases the animal from that very, very rigid automatic response of selecting more, and allows them to use this cultural rule that we had established. It was quite extraordinary.

NARRATOR:  [voice-over] Chimps do acquire complex skills in the wild, but this happens slowly, over many years. Some groups have learned to use stones as hammers and anvils to crack nuts. In Atlanta, they found that Kanzi was able to grasp such a skill with amazing ease by watching a demonstration and then trying it for himself in the forest.
Kanzi was also able to make his own tools after watching a demonstration by a visiting archaeologist. He went on to show particular insight and creativity in his approach to problem-solving. He was presented with this puzzle box, held closed by a strong rope. He quickly caught on to the solution, and also found his own way of making a sharp tool by throwing, rather than striking the stones together in his hand. His way was just as effective. Kanzi's ability to observe tool use and quickly adapt it for his own purposes is very significant. This facility is not seen in wild chimpanzees, only in those who have been exposed to human culture. Perhaps we are seeing in a chimpanzee the same stages of learning that our ancestors must have experienced.
Going back in time from the human species today, we see that some three million years ago our ancestor might have looked something like this, not very different yet from the way the bonobo chimps look today when they walk upright, with hands free. Archaeology can reveal much about our own past, but words leave no fossils, and scientists have to depend upon comparisons between living species to draw conclusions about how our own capacity for language might have come about. Sue Savage-Rumbaugh's findings point to an origin of language which goes back several million years, and may even predate human evolution. 

To do this sort of work with great apes, you have to become part of the group and win their respect. Some rules, like not jumping on the researcher's head, have to be enforced, otherwise working with adult apes would be too dangerous. Physically, humans are no match for chimpanzees.

Dr. SAVAGE-RUMBAUGH:  I'm not going to have it.

NARRATOR:  [voice-over] Here, young Tumuli [sp?] has broken the rule, and Sue reprimands her. It is interesting how Kanzi seems to intercede on behalf of his younger sister. Kanzi and Panbenisha have had intensive contact with humans every day and have been shown to understand human speech.

Dr. SAVAGE-RUMBAUGH:  Tumuli, some bark.

NARRATOR:  [voice-over] Young Tumuli was reared by her mother, and shows no comprehension of spoken English.

Dr. SAVAGE-RUMBAUGH:  Tumuli, Tumuli. That's some bark. Thank you, Panbenisha. Tumuli.

NARRATOR:  [voice-over] Sometimes it seems as though Kanzi is able to act as a kind of interpreter, showing his younger sister what the words mean.

Dr. SAVAGE-RUMBAUGH:  Tumuli, could you slap Kanzi? Tumuli, you, slap Kanzi. You slap Kanzi. You slap Kanzi. Tumuli, could you give Kanzi a hug? Tumuli, could you groom Kanzi? He's asking you to groom him. Look, he put your hand up there. Isn't that nice? Go ahead, groom Kanzi. Look, he's showing you.

Mr. RUMBAUGH:  Now, more so than ever, the data are so strong that every reasonable scientist, every reasonable person should be willing to conclude that yes, indeed, the chimpanzee does have not just the appearance of language, but does have the competence for language, particularly if it is reared from birth as though it is something it is not, namely, a human child.

NARRATOR:  [voice-over] So the more completely a chimpanzee is immersed a child, the researcher seems to transmit the necessary knowledge through the everyday process of caregiving. Treating a young ape as a human child is natural enough, but extending all the trappings of human culture to adult apes presents a number of practical problems. The chimps hand-reared by the Gardners over 20 years ago now live at Central Washington University, under the care of Roger and Debbi Fouts.

DEBBI FOUTS, Central Washington University:  They have four rooms and five tunnels, and it could be deadly boring, but instead, we try to make each day a unique, interesting day.

NARRATOR:  [voice-over] These five chimps lived as a social group in temporary accommodations on the third floor of the psychology building. 
This is Washoe, the chimp who, 25 years ago, learned sign language in Reno. She and the other Gardner chimps still communicate with the researchers in sign language.

Ms. FOUTS:  During the day they have any manner of things to play with. They have buckets of Kool-Aid with hoses for straws. They can dip for yogurt. They have dress-up clothes. They have brushes, toothbrushes. 
[to chimp] You want what? You want a toothbrush ?

NARRATOR:  [voice-over] Ape language researchers now believe that once a chimp has become accustomed to a rich human environment, it would be a cruel deprivation to lose it. These adult chimps could live for another 30 years or more. They'll require constant human care and attention.

RESEARCH ASSISTANT:  They have a lunchtime meal that is served to them. They- if they would like some more - it's usually a vegetable kind of a soup that has protein in it - they ask for more soup, and then they're served more soup. We don't ever just throw bowls in. We don't necessarily spoonfeed them. They are offered spoons and dishes to eat.

NARRATOR:  [voice-over] English is spoken here, but sign language still predominates between chimp and human. Debbi Fouts has published work describing the signing between the chimps when no one else is present. 
Students have observed how signs are used by the chimps to initiate conversations. Before she was brought here, Washoe had already given birth to two infants, neither of whom lived beyond a few weeks. The second baby died after being taken away from her for medical treatment. It was Roger Fouts's job to make Washoe understand what had happened.

ROGER FOUTS, Central Washington University:  I had to go back the next morning, and she was very depressed, of course, and quite, quite alone, not signing with anybody. And so I went in, and she came up to me, her eyes lit up. She came up to me and she said, `Baby, holding, holding.' And it was a question, she was saying, basically, `Where's my baby?' And I had to tell her, I said, `He's dead. He's finished.' And with that, the baby sign literally dropped into her lap, her head dropped, and she moved away into the corner and stopped signing.

So we searched and searched and searched, and 10 days after his death, we finally found a replacement. It was Lulis [sp?], he was 10 months old. The next morning I went in and I signed, `Have baby.' And she immediately started signing, `Baby, baby,' getting very excited, `Baby, baby, baby, baby, baby,' slapping her hands, bipedal, hair up, extreme excitement. And then when she signed, `My baby,' I knew we were in trouble.

I knew she misunderstood me. So I went out and got him, 10-month-old, he was on my chest, came in, and then went in the enclosure with her, and when I got about maybe two or three feet away she got a good look at him. And all this time she's signing, `Baby, baby, baby, baby,' and she gets a good look at him and she just sits down. And then she looks back up, and the she signs, `Baby.' Obviously, she'd realized it wasn't her baby any longer, it was a strange baby.

That night she tried to sleep with him like her own baby. She always took her to bed with her and slept with her, and so on, and slept with him. She tried to do that with Lulis, too, and he would have nothing to do with it. He laid down on his own end of the bench, and when she'd come he'd move, until finally she let him. And then, at 4:00 in the morning, she woke up, went into a bipedal swagger, banged the enclosure and signed, `Come, hug,' slapping her hands, making a loud noise, and with that he jumped up out of a sound sleep and leapt into the nearest hairy arms that were available, which were hers, and she literally engulfed him and lay back down. And from that moment on, they were inseparable.
[to chimp] Washoe, Washoe, hey, hey, what's this?

NARRATOR:  [voice-over] From the time Lulis arrived, the researchers deliberately restricted their signing to Washoe, to test whether or not Lulis would learn sign language without human intervention. By the time he was five, they reported that Lulis had learned a total of 51 signs.

Mr. FOUTS:  Lulis.

NARRATOR:  [voice-over] In May, 1993, the chimps were finally moved out of the psychology building into a new specially designed home.

Mr. FOUTS;  If you want good research, you have to have proper care. You owe them that, at least. They're not volunteers, they don't want to do this. We're still at the notion of treating them like a hairy test tube, and that's an abomination. They are not hairy test tubes. They are thinking, feeling, emotional beings with wants, desires in a life, just like we do.

NARRATOR:  [voice-over] As this research proceeds, it could have some powerful implications. If chimpanzees show they can acquire human language, use it to communicate, and manipulate abstract symbols like words and numbers, then the possibility is that chimp and human minds have a great deal more in common than we thought.

Ms. GARDNER:  The uses and misuses to which we put animals certainly have to do with lines that we draw differentiating ourselves from them. I'm certain that even within human populations, when we behave in a way that is not humanitarian, it is because we draw a distinction. `If these people are not like me, they don't have the same rights.' By drawing a continuity, I think we behave in a more human fashion to all concerned.

Mr. GARDNER:  The reason why this research has become so controversial is that it's part of a very long battle, not the battle over whether human beings are descended from chimpanzees, but the battle over whether the same laws of nature apply to mice and leopards and chimpanzees and human beings.
Most of the history of modern science has been a retreat from the notion of human speciality, and people more or less have accepted this now about blood and bone, but behavior, emotion, cognition, that's very hard. You can see the history of science of behavior as a slow, retreating battle with separatists drawing the wagons in an ever-tightening circle. And right now the last great stand seems to be made over language.

Dr. SAVAGE-RUMBAUGH:  If we take seriously the fact that the chimpanzee has an understanding of language and an ability to produce language, it raises all kinds of other questions. Are they conscious? How should we treat them? Are they rational? Should they have chimpanzee rights? And we're not prepared to answer all of these questions. We don't really know.

Serie written and directed by  Jenny Jones for NHK Japan.

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