Great ape language

Research into great ape language has involved teaching chimpanzees, bonobos, gorillas, and orangutans to communicate with human beings and with each other using sign language, physical tokens, and lexigrams; see Yerkish. Some primatologists argue that the primates' use of these tools indicates their ability to use "language", although this is not consistent with some definitions of that term.

Questions in animal language research

Animal language research attempts to answer the following questions:

Non-human apes that demonstrate understanding

Non-human animals have been recorded to have produced behaviors that are consistent with meanings accorded to human sentence productions. (A production is a stream of lexemes with semantic content. A language is grammar and a set of lexemes. A sentence, or statement, is a stream of lexemes that obeys a grammar, with a beginning and an end.) Some animals in the following species can be said to "understand" (receive), and some can "apply" (produce) consistent, appropriate, grammatical streams of communication. David Premack and Jacques Vauclair have cited language research for the following animals (but see "Criticisms of primate language research", below):

Primate use of sign language

Sign language and computer keyboards are used in primate language research because non-human primate vocal cords cannot close fully,[11][12] and they have less control of the tongue and lower jaw.[13] However, primates do possess the manual dexterity required for keyboard operation.

Many researchers into animal language have presented the results of the studies described below as evidence of linguistic abilities in animals. Many of their conclusions have been disputed.[14][15]

It is now generally accepted that apes can learn to sign and are able to communicate with humans. However, it is disputed as to whether they can form syntax to manipulate such signs.

Washoe

Main article: Washoe (chimpanzee)

Washoe, a common chimpanzee, was caught in the wild in 1966. When she was about ten months old, she was received by the husband-and-wife research team of Beatrix T. Gardner and R. Allen Gardner.[16] Chimpanzees are completely dependent until two years of age and semi-dependent until the age of four. Full adult growth is reached between 12 and 16 years of age. Accordingly, the Gardners received her at an appropriate age for research into language development. The Gardners tried to make Washoe's environment as similar as possible to what a human infant with deaf parents would experience. There was always a researcher or assistant in attendance during Washoe's waking hours. Every researcher communicated with Washoe by using American Sign Language (ASL), minimizing the use of the spoken voice. The researchers acted as friends and companions to Washoe, using various games to make the learning as exciting as possible.

The Gardners used many different training methods:

The results of the Gardners' efforts were as follows:

Washoe also taught other chimpanzees, such as Loulis, some ASL signs without any help from humans.

Nim Chimpsky

Main article: Nim Chimpsky

Linguistic critics challenged the animal trainers to demonstrate that Washoe was actually using language and not symbols. The null hypothesis was that the Gardners were using conditioning to teach the chimpanzee to use hand formations in certain contexts to create desirable outcomes, and that they had not learned the same linguistic rules that humans innately learn.

In response to this challenge, the chimpanzee Nim Chimpsky (whose name is a play on linguist Noam Chomsky) was taught to communicate using sign language in studies led by Herbert S. Terrace. In 44 months, Nim Chimpsky learned 125 signs.[17] However, linguistic analysis of Nim's communications demonstrated that Nim's use was symbolic, and lacked grammar, or rules, of the kind that humans use in communicating via language. This constitutes a chimpanzee vocabulary learning rate of roughly 0.1 words per day. This rate is not comparable to the average college-educated English-speaking human who learns roughly 14 words per day between ages 2 and 22.[18]

Koko

Main article: Koko (gorilla)

Dr. Francine "Penny" Patterson, a student of the Gardners, in 1972 began an ongoing program to teach ASL to a lowlands gorilla. Unlike the Gardners she did not limit her English speech around Koko, and as a result Koko understands approximately 1,000 ASL signs and 2,000 English words. Her results were similar to the Gardners' results with chimpanzees; although the gorilla learned a large number of signs she never understood grammar or symbolic speech, and hasn't displayed any cognition beyond that of a 2-3 year old human child.

Gestural communication in the wild

In the first long-term study of gestural communication in the wild, researchers from the University of St Andrews, working at the Budongo Conservation Field Station in Uganda, found a large repertoire of at least 66 different gestures (including bodily movements), which included almost all types of gesture reported in studies from other chimpanzee sites both in captivity and the wild. This led them to argue that the repertoire of available gesture types that can be employed in natural chimpanzee gestural communication is species-typical.[19][20] In a parallel study at the same site, researchers from Stirling found 30 different manual gesture types in mature chimpanzees; many of which appear similar to human manual gestures such as arm beckon, point, clap and flail.[21]

Plastic tokens

Sarah and two other chimpanzees, Elizabeth and Peony, in the research programs of David Premack, demonstrated the ability to produce grammatical streams of token selections. The selections came from a vocabulary of several dozen plastic tokens; it took each of the chimpanzees hundreds of trials to reliably associate a token with a referent, such as an apple or banana. The tokens were chosen to be completely different in appearance from the referents. After learning these protocols, Sarah was then able to associate other tokens with consistent behaviors, such as negation, name-of, and if-then. The plastic tokens were placed on a magnetic slate, within a rectangular frame in a line. The tokens had to be selected and placed in a consistent order (a grammar) in order for the trainers to reward the chimpanzees.

One other chimpanzee, Gussie, was trained along with Sarah but failed to learn a single word. Other chimpanzees in the projects were not trained in the use of the tokens. All nine of the chimpanzees could understand gestures, such as supplication when asking for food; similarly, all nine could point to indicate some object, a gesture which is not seen in the wild. The supplication is seen in the wild, as a form of communication with other chimpanzees.[22]

A juvenile Sumatran orangutan Aazk (named after the American Association of Zookeepers) who lived at the Roeding Park Zoo (Fresno, California) was taught by Gary L. Shapiro from 1973 to 1975 how to "read & write" with plastic children's letters, following the training techniques of David Premack. The technique of conditional discrimination was used such that the orangutan could eventually distinguish plastic letter (symbols) as representations of referents (e.g., object, actions) and "read" an increasingly longer series of symbols to obtain a referent (e.g., fruit) or "write" an increasingly longer series of symbols to request or describe a referent. While no claim of linguistic competence was made, Aazk's performance demonstrated design features of language, many similar to those demonstrated by Premack's chimpanzee, Sarah.

Kanzi

Kanzi, a bonobo, is believed to understand more human language than any other nonhuman animal in the world. Kanzi apparently learned by eavesdropping on the keyboard lessons researcher Sue Savage-Rumbaugh was giving to his adoptive mother. Kanzi learned to communicate with a Lexigram board, pushing symbols that stand for words. The board is wired to a computer, so the word is then vocalized out loud by the computer. This helps Kanzi develop his vocabulary and enables him to communicate with researchers.

One day, Rumbaugh used the computer to say to Kanzi, "Can you make the dog bite the snake?" It is believed Kanzi had never heard this sentence before. In answering the question, Kanzi searched among the objects present until he found a toy dog and a toy snake, put the snake in the dog's mouth, and used his thumb and finger to close the dog's mouth over the snake. In 2001, Alexander Fiske-Harrison, writing in the Financial Times, observed that Kanzi was "asked by an invisible interrogator through head-phones (to avoid cueing) to identify 35 different items in 180 trials. His success rate was 93 per cent."[23] In further testing, beginning when he was 7 ½ years old, Kanzi was asked 416 complex questions, responding correctly over 74% of the time. Kanzi has been observed verbalizing a meaningful noun to his sister.[24]

Limitations of ape language

Despite their impressive (although still sometimes disputed) achievements, Kanzi and other apes, who participated in similar experiments, failed to ask questions themselves. Joseph Jordania suggested that the ability to ask questions is probably the central cognitive element that distinguishes human and animal cognitive abilities.[25] (However, a parrot named Alex was apparently able to ask simple questions. He asked what color he was, and learned "grey" after being told the answer six times.[26]) Enculturated apes, who underwent extensive language training programs, successfully learned to answer quite complex questions and requests (including question words "who", "what", "where"), although so far they failed to learn how to ask questions themselves. For example, David and Anne Premack wrote: "Though she [Sarah] understood the question, she did not herself ask any questions – unlike the child who asks interminable questions, such as What that? Who making noise? When Daddy come home? Me go Granny's house? Where puppy? Sarah never delayed the departure of her trainer after her lessons by asking where the trainer was going, when she was returning, or anything else".[27] The ability to ask questions is sometimes assessed in relation to comprehension of syntactic structures. Jordania suggested that this approach is not justified, as (1) questioning is primarily a cognitive ability, and (2) questions can be asked without the use of syntactic structures (with the use of specific intonation only). It is widely accepted that the first questions are asked by humans during their early infancy, at the pre-syntactic, one word stage of language development, with the use of question intonation.[28]

Criticisms of primate language research

Some scientists, including MIT linguist Noam Chomsky and cognitive scientist Steven Pinker, are skeptical about claims made for great ape language research.[29][30] Among the reasons for skepticism are the differences in ease with which human beings and apes can learn language; there are also questions of whether there is a clear beginning and end to the signed gestures and whether the apes actually understand language or are simply doing a clever trick for a reward.

While vocabulary words from American Sign Language are used to train the apes, native users of ASL note that mere knowledge of ASL's vocabulary does not equate to ASL.

See also

Researchers

Research subjects

Notes

  1. Plooij, F.X. (1978) "Some basic traits of language in wild chimpanzees?" in A. Lock (ed.) Action, Gesture and Symbol New York: Academic Press.
  2. Nishida, T. (1968) "The social group of wild chimpanzees in the Mahali Mountains". Primates 9, 167-224
  3. Premack, D. (1985) "'Gavagai!' or the future of the animal language controversy". Cognition 19, 207-296
  4. Gardner, R.A. and Gardner, B.T. (1969), "Teaching Sign Language to a Chimpanzee", Science 165, 664-672.
  5. Gardner, R.A., Gardner, B.T., and Van Cantfort, T.E. (1989), Teaching Sign Language to Chimpanzees, Albany: SUNY Press.
  6. Terrace, H.S. (1979). Nim: A chimpanzee who learned Sign Language New York: Knopf.
  7. 1 2 Savage-Rumbaugh, E.S, Rumbaugh, D.M., McDonald, K. (1985). "Language learning in two species of apes". Neuroscience and Biobehavioral Reviews 9, 653-665.
  8. Savage-Rumbaugh, E.S., McDonald, K, Sevcik, R.A., Hopkins, W.D., and Rupert E. (1986). "Spontaneous symbol acquisition and communicative use by pygmy chimpanzees (Pan paniscus)". Journal of Experimental Psychology:General 115, 211-235.
  9. Patterson, F.G. and Linden E. (1981), The education of Koko, New York: Holt, Rinehart and Winston
  10. Miles, H.L. (1990) "The cognitive foundations for reference in a signing orangutan" in S.T. Parker and K.R. Gibson (eds.) "Language" and intelligence in monkeys and apes: Comparative Developmental Perspectives. Cambridge Univ. Press. pp.511-539.
  11. Beard, Robert. "Can Chimpanzees Talk?". Dr. Goodword's Office. AlphaDictionary.com.
  12. Falk, Dean (July 1975). "Comparative Anatomy of the Larynx in Man and the Chimpanzee: Implications for Language in Neanderthal". American Journal of Physical Anthropology. 43: 123–132. doi:10.1002/ajpa.1330430116.
  13. Bolles, Edmund Blair (1 October 2006). "The Human FOXP2 Gene". Babel's Dawn.
  14. "Animal Communication". Department of Linguistics, The Ohio State University. 1994. Retrieved 2008-02-21.
  15. Wallman, Joel (1992). Aping Language. Cambridge University Press. ISBN 0-521-40666-8.
  16. "Meet the Family – Washoe's Biography". Friends of Washoe. Retrieved 2008-02-21.
  17. Terrace, H. S. (1979). Nim. New York: Knopf.
  18. ed. Dale Purves (ed.). Neuroscience (2nd ed.). p. 591.
  19. Hobaiter & Byrne, 2011, The gestural repertoire of the wild chimpanzee. Animal Cognition 14:745-767
  20. BBC News
  21. Premack and Premack, The mind of an ape.
  22. Fiske-Harrison, Alexander 'Talking With Apes', Financial Times, Weekend, 24–25 November 2001
  23. Sue Savage-Rumbaugh, Smithsonian magazine, November 2006
  24. Jordania, Joseph (2006). Who Asked the First Question? The Origins of Human Choral Singing, Intelligence, Language and Speech. Tbilisi: Logos. ISBN 99940-31-81-3.
  25. Wise, Steven M. (2002). Drawing the Line. Cambridge, MA: Perseus Books. p. 107. ISBN 0-7382-0340-8.
  26. Premack, David; Premack, Ann J. (1983). The mind of an ape. New York, London: W. W. Norton & Company. p. 29.
  27. Crystal, David (1987). The Cambridge Encyclopedia of Language. Cambridge. Pg. 241, 143: Cambridge University.
  28. "On the Myth of Ape Language". 2007/2008. Retrieved 2011-03-24. Check date values in: |date= (help)
  29. Pinker, Steven (2004). "The Language Instinct" (PDF). Retrieved 2011-03-24.

References

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