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1. Teaching Sign Language to a Chimpanzee R. Allen Gardner; Beatrice T. Gardner Science, New Series, Vol. 165, No. 3894. (Aug. 15, 1969), pp. 664-672. Stable URL:…
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  • 1. Teaching Sign Language to a Chimpanzee R. Allen Gardner; Beatrice T. Gardner Science, New Series, Vol. 165, No. 3894. (Aug. 15, 1969), pp. 664-672. Stable URL: http://links.jstor.org/sici?sici=0036-8075%2819690815%293%3A165%3A3894%3C664%3ATSLTAC%3E2.0.CO%3B2-Z Science is currently published by American Association for the Advancement of Science. Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/about/terms.html. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/journals/aaas.html. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. The JSTOR Archive is a trusted digital repository providing for long-term preservation and access to leading academic journals and scholarly literature from around the world. The Archive is supported by libraries, scholarly societies, publishers, and foundations. It is an initiative of JSTOR, a not-for-profit organization with a mission to help the scholarly community take advantage of advances in technology. For more information regarding JSTOR, please contact support@jstor.org. http://www.jstor.org Sun Dec 2 11:24:01 2007
  • 2. We have always had to reckon with the likelihood that at some point Washoe's physical maturity will make this proce- dure prohibitively dangerous. A more serious disadvantage is that Teaching Sign Language human speech sounds are unsuitable as a mediunl of con~munication for the to a Chimpanzee chimpanzee. The vocal apparatus of the chimpanzee is very different from that of man (2). More important, the vocal behavior of the chimpanzee is very dif- A standardized system of gestures provides a means ferent from that of man. Chimpanzees do make many different sounds, but of two-way communication with a chimpanzee. generally vocalization occurs in situa- tions of high excitenlent and tends to be specific to the exciting situations. R. Allen Gardner and Beatrice T. Gardner Undisturbed, chimpanzees are usually silent. Thus, it is unlikely that a chim- panzee could be trained to make refined use of its vocalizations. Moreover, the Preliminary Considerations The extenl to which another species intensive work of Hayes and Hayes might be able to use human language (3) with the chimpanzee Viki indicates The chimpanzee as a subject. Some is a classical problem in comparative that a vocal language is not appropriate psychology. One approach to this prob- discussion of the chimpanzee as an for this species. The Hayeses used lem is to consider the nature of lan- experinlental subject is in order because modern, sophisticated, psychological this species is relatively uncommon in guage, the processes of learning, the methods and seem to have spared no neural mechanisms of learning and of the psychological laboratory. Whether effort to teach Viki to make speech language, and the genetic basis of these or not the chimpanzee is the most in- sounds. Yet in 6 years Viki learned mechanisms, and then, while recogniz- telligent animal after man can be dis- only four sounds that approximated ing certain gaps in what is known puted; the gorilla, the orangutan, and English words (4). about these factors, to attempt to arrive even the dolphin have their loyal par- Use of the hands, however, is a at an answer by dint of careful scholar- tisans in this debate. Nevertheless, it is prominent feature of chimpanzee be- ship (I). An alternative approach is to generally conceded that chinlpanzees havior; nlanipulatory mechanical prob- try to teach a form of human lan- are highly intelligent, and that mem- lems are their forte. More to the point, guage to an animal. We chose the lat- bers of this species might be intelligent even caged, laboratory chimpanzees de- ter alternative and, in June 1966, began enough for our purposes. Of equal or velop begging and similar gestures spon- training an infant female chimpanzee, greater importance is their sociability taneously ( 5 ) , while individuals that namcd Washoe, to use the gestural lan- and their capacity for forming strong have had extensive contact with human guage of the deaf. Within the first 22 attachments to human beings. We want beings have displayed an even wider months of training it became evident variety of conlmunicative gestures ( 6 ) . to emphasize this trait of sociability; it that we had been correct in at least one seems highly likely that it is essential In our choice of sign language we major aspect of method, the use of a were influenced more by the behavioral for the development of language in gestural language. Additional aspects of human beings, and it was a primary evidence that this medium of conlmuni- method have evolved in the course of consideration in our choice of a chim- cation was appropriate to the species the project. These and some inlplica- panzee as a subject. than by anatomical evidence of struc- tions of our early results can now be tural similarity between the hands of Affectionate as chimpanzees are, described in a way that may be useful chimpanzees and of men. The Hayeses they are still wild animals, and this is in other studies of communicative be- point out that human tools and mechan- a serious disadvantage. Most psycholo- havior. Accordingly, in this article we ical devices are constructed to fit the gists are accustomed to working with discuss the considerations which led us human hand, yet chimpanzees have animals that have been chosen, and to use the chimpanzee as a subject and little difficulty in using these devices sonletinles bred, for docility and adap- American Sign Language (the language with great skill. Nevertheless, they tability to laboratory procedures. The used by the deaf in North America) as seem unable to adapt their vocalizations difficulties presented by the wild nature a mediunl of comnlunication; describe to approximate human speech. of an experimental animal must not the general methods of training as they Psychologists who work extensively be underestimated. Chimpanzees are were initially conceived and as they de- with the instrumental conditioning of also very strong animals; a full-grown veloped in the course of the project; animals become sensitive to the need specimen is likely to weigh more than and summarize those results that could to use responses that are suited to the 120 pounds (55 kilograms) and is be reported with some degree of confi- species they wish to study. Lever- estimated to be from three to five times dence by the end of the first phase of pressing in rats is not an arbitrary re- as strong as a man, pound-for-pound. the project. sponse invented by Skinner to confound Coupled with the wildness, this great the mentalists; it is a type of response strength presents serious difficulties for The authors are, respectively, (i) professor of commonly made by rats when they are a procedure that requires interaction at psychology and (ii) research associate and lec- turer in pychology at the University of Nevada, first placed in a Skinner box. The ex- close quarters with a free-living animal. Reno 89507. SCIENCE, VOL. 165 664
  • 3. quisite control of instrumental behavior that seem quite arbitrary today once we reasoned that the dangers of start- by schedules of reward is achieved had an iconic origin that was lost ing too late were much greater than the only if the original responses are well through years of stylized usage. Thus, dangers of starting too early, and we chosen. We chose a language based on the signs of ASL are neither' uniformly sought the youngest infant we could gestures because we reasoned that ges- arbitrary nor uniformly iconic; rather get. Newborn laboratory chimpanzees tures for the chimpanzee should be the degree of abstraction varies from are very scarce, and we found that the analogous to bar-pressing for rats, key- sign to sign over a wide range. This youngest laboratory infant we could would seem to be a useful property of pecking for pigeons, and babbling for get would be about 2 years old at the ASL for our research. humans. time we planned to start the project. It American Sign Language. Two sys- The literate deaf typically use a seemed preferable to obtain a wild- tems of manual communication are combination of ASL and finger spell- caught infant. Wild-caught infants are used by the deaf. One system is the ing; for purposes of this project we have usually at least 8 to 1 0 months old be- manual alphabet, or finger spelling, in avoided the use of finger spelling as fore they are available for research. which configurations of the hand cor- much as possible. A great range of ex- This is because infants rarely reach the respond to letters of the alphabet. I n pression is possible within the limits of United States before they are 5 months this system the words of a spoken ASL. We soon found that a good way old, and to this age must be added 1 language, such as English, can be to practice signing among ourselves was or 2 months before final purchase and spelled out manually. The other system, to render familiar songs and poetry into 2 or 3 months for quarantine and sign language, consists of a set of signs; as far as we can judge, there is other medical services. manual configurations and gestures that no message that cannot be rendered We named our chimpanzee Washoe correspond to particular words or con- faithfully (apart from the usual prob- for Washoe County, the home of the cepts. Unlike finger spelling, which is lems of translation from one language University of Nevada. Her exact age the direct encoding of a spoken lan- to another). Technical terms and proper will never be ltnown, but from her guage, sign languages have their own names are a problem when first in- weight and dentition we estimated her rules of usage. Word-for-sign transla- troduced, but within any comnlunity of age to be between 8 and 1 4 months at tion between a spoken language and a signers it is easy to agree on a conven- the end of June 1966, when she first ar- sign language yields results that are tion for any conlmonly used term. For rived at our laboratory. (Her dentition similar to those of word-for-word trans- example, among ourselves we do not has continued to agree with this initial lation between two spoken languages: finger-spell the words psychologirt and estimate, but her weight has increased the translation is often passable, though psychology, but render them as quot;think rather more than would be expected.) awkward, but it can also be ambiguous doctorquot; and quot;think science.quot; Or, among This is very young for a chimpanzee. or quite nonsensical. Also, there are users of ASL, quot;Californiaquot; can be fin- The best available information indicates national and regional variations in sign ger-spelled but is commonly rendered that infants are conlpletely dependent languages that are comparable to those as quot;golden playland.quot; (Incidentally, the until the age of 2 years and semi- of spoken languages. sign for quot;goldquot; is made by plucking at dependent until the age of 4; the first We chose for this project the Amer- the earlobe with thumb and forefinger, signs of sexual maturity (for example, indicating an earring-another example ican Sign Language (ASL), which, with menstruation, sexual swelling) begin to of an iconic sign that is at the same certain regional variations, is used by appear at about 8 years, and full adult time arbitrary and stylized.) the deaf in North America. This partic- growth is reached between the ages of ular sign language has recently been The fact that ASL is in current use 1 2 and 16 (8). As for the complete life- the subject of formal analysis (7). The by human beings is an additional advan- span, captive specimens have survived ASL can be compared to pictograph tage. The early linguistic environment for well over 40 years. Washoe was writing in which some symbols are of the deaf children of deaf parents is indeed very young when she arrived; quite arbitrary and some are quite in some respects similar to the linguis- she did not have her first canines o r representational or iconic, but all are tic environment that we could provide molars, her hand-eye coordination was arbitrary to some degree. For example, for an experimental subject. This should rudimentary, she had only begun to in ASL the sign for quot;alwaysquot; is made permit some comparative evaluation of crawl about, and she slept a great deal. by holding the hand in a fist, index Washoe's eventual level of competence. Apart from making friends with her finger extended (the pointing hand), For example, in discussing Washoe's and adapting her to the daily routine, early performance with deaf parents while rotating the arm at the elbow. we could accomplish little during the This is clearly an arbitrary representa- we have !been told that many of her first few months. tion of the concept quot;always.quot; The sign variants of standard signs are similar to Laboratory conditions. At the outset for quot;flower,quot; however, is highly iconic; the baby-talk variants commonly ob- we were quite sure that Washoe could it is made by holding the fingers of one served when human children sign. learn to make various signs in order hand extended, all five fingertips touch- Washoe. Having decided on a species to obtain food, drink, and other things. ing (the tapered hand), and touching and a medium of communication, our For the project to be a success, we the fingertips first to one nostril then next concern was to obtain an experi- felt that something more must be de- to the other, as if sniffing a flower. mental subject. It is altogether possible veloped. We wanted Washoe not only While this is an iconic sign for quot;flower,quot; that there is some critical early age for to ask for objects but to answer ques- it is only one of a number of conven- the acquisition of this type of behavior. tions about them and also to ask us tions by which the concept quot;flowerquot; On the other hand, newborn chimpan- questions. We wanted to develop be- could be iconically represented; it is havior that could be described as con- zees tend to be quite helpless and vege- thus arbitrary to some degree. Un- tative. They are also considerably less versation. With this in mind, we at- doubtedly, many of the signs of ASL hardy than older infants. Nevertheless, tempted to provide Washoe with an 15 AUGUST 1969
  • 4. environment that might be conducive and hands are clapped for attention. imitation of this sort has not been an to this sort of behavior. Confinement The rule is that all meaningful sounds, important method for introducing new was to be minimal, about the same as whether vocalized or not, must be signs into Washoe's vocabulary. that of human infants. H e r human sounds that a chimpanzee can imitate. As a methd of prompting, we have companions were to be friends and been able to use imitation extensively playmates as well as providers and to increase the frequency and refine the protectors, and they were to introduce Training Methods form of signs. Washoe sometitnes fails a great many games and activities that to use a new sign in an appropriate would be likely to result in maximum Iv~zitatio~z. h e imitativeness of apes situation, o r uses another, incorrect T inter;lction with Washoe. is proverbial, and rightly so. Those who sign. A t such times we can make the In practice, such an environment is have worked closely with chimpanzees correct sign to Washoe, repeating the readily achieved with a chimpanzee; have frequently remarked on their performance until she makes the sign hontis of wartn affection have always readiness to engage in visually guided herself. (With more stable signs, more been established between Washoe and imitation. Consider the following typi- indirect forms of prompting can be her several human companions. W e used-for example, pointing at, o r cal comment of Yerkes (9): quot;Chi~urand have enjoyed the interaction almost touching, Washoe's hand o r a part of Panzee would imitate many of my acts, as much as Washoe has, within the hut never have I heard them iniitate a her body that should be involved in limits of human endurance. A number sound and rarely make a sound pecu- the sign; making the sign for quot;sign,quot; of h t ~ m a n companions have been en- liarly their own in response to mine. As which is equivalent to saying quot;Speak listed to participate in the project and preriiously stated, their imitative tend- upquot;; o r asking a question in signs, such relieve each other at intervals, so that ency is as remarkable for its specializa- as quot;What d o you want?quot; o r quot;What :it least one person would be with tion and limitations as for its strength. is it?quot;) Again, with new signs, and Washoe during all her waking hours. It seems to be controlled chiefly by often with old signs as well, Washoe At first we feared that such frequent visual stimuli. Things which are seen can lapse into what we refer to as changes would be disturbing, but tend to bc imitated or reproduced. poor quot;diction.quot; Of course, a great deal Washoe seemed to adapt very well to What is heard is not reproduced. Ob- of slurring and a wide range of variants this proccdure. Apparently it is pos- are permitted in ASI, as in any spoken viously an animal which lacks the sihlc to provide an infant chinlpanzee language. In any event, Washoe's dic- tendency to reinstate auditory stin-luli- with atfection on a shift basis. tion has frequently been i~iiprovedby in other words to imitate sounds-can- All o f Washoe's human companions not reasonably be expected to talk. The the simple device of repeating, in ex- havc heen 1,equired to master ASI, and human infant exhibits this tendency to aggeratedly correct form, the sign she a retnarkable degree. So also does the has just made, until she repeats it her- to usc it extensively in her presence, in parrot. If the imitative tendency of the self in more correct for~ii. On the association with interesting activities parrot could be coupled with the qr~ality whole, she has responded quite well to and events and also in a general way, prompting, but there are strict limits as one chatters at a h u ~ i i a ninfant in of intellige~iceof the chimpanzee, the to its use with n wild animal-one that thc course of the day. The ASL has latter undoubtedly could speak.quot; I n the course of their work with Viki, is probably quite spoiled, besides. been used altnost exclusively, although th'e Hayeses devised a galiie in which Pressed too hard, Washoe can become occa3ional finger spelling has been Viki would imitate various actions on completely diverted from her original permitted. Fro111time to time, of course, hearing the command quot;Do thisquot; ( 1 0 ) . object; she may ask for something en- there are lapses into spoken English, Once established, this was an effective tirely different, run away, go into a as when medical personnel must ex- tantrum, or even bite her tutor. aminc Washoe. A t one time, we con- means of training Vilti to perform Chi~iipanzeesalso imitate, after some sidcrecl :in alternative procedure i n actions that could be visually guided. The same method should be adniiral>ly delay, and this delayed imitation c a n which we would sign and speak English suited to training a chimpanzee to use be quite elaborate (10). T h e follow- to Washoe siniultaneo~~sly, thus giving sign language; accordingly we hav
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