is the modeling of human language in non human animal systems. While the term is widely used, most researchers agree that animal languages are not as complex or expressive as human language
Some researchers argue that there are significant differences separating human language from animal communication even at its most complex, and that the underlying principles are not related.
Others argue that an evolutionary continuum exists between the communication methods these animals use and human language.
The following properties of human language have been argued to separate it from animal communication:
- Arbitrariness: There is no rational relationship between a sound or sign and its meaning. (There is nothing "housy" about the word "house".)
- Cultural transmission: Language is passed from one language user to the next, consciously or unconsciously.
- Discreteness: Language is composed of discrete units that are used in combination to create meaning.
- Displacement: Languages can be used to communicate ideas about things that are not in the immediate vicinity either spatially or temporally.
- Duality: Language works on two levels at once, a surface level and a semantic (meaningful) level.
- Metalinguistics: Ability to discuss language itself.
- Productivity: A finite number of units can be used to create a very large number of utterances.
Research with apes, like that of Francine Patterson with Koko, suggested that apes are capable of using language that meets some of these requirements.
In the wild chimpanzees have been seen "talking" to each other, when warning about approaching danger. For example, if one chimpanzee sees a snake, he makes a low, rumbling noise, signalling for all the other chimps to climb into nearby trees.
Arbitrariness has been noted in meerkat calls; bee dances show elements of spatial displacement; and cultural transmission has occurred with the offspring of many of the great apes who have been taught sign languages, the celebrated bonobos Kanzi and Panbanisha being examples.
However, these single features alone do not qualify such instances of communication as being true language.
Non-Primates: Studied examples
The most studied examples of animal languages are:
- Bee dance - used to communicate direction and distance of food source in many species of bees
- Bird songs - songbirds can be very articulate. African Grey Parrots are famous for their ability to mimic human language, and at least one specimen, Alex, appeared able to answer a number of simple questions about objects he is presented with. Parrots, hummingbirds and songbirds- display vocal learning patterns.
- Whale songs - Two groups of whales, the Humpback Whale and the subspecies of Blue Whale found in the Indian Ocean, are known to produce the repetitious sounds at varying frequencies known as whale song. Male Humpback Whales perform these vocalizations only during the mating season, and so it is surmised the purpose of songs is to aid sexual selection. Humpbacks also make a sound called the feeding call. This is a long sound (5 to 10 s duration) of near constant frequency. Humpbacks generally feed cooperatively by gathering in groups, swimming underneath shoals of fish and all lunging up vertically through the fish and out of the water together. Prior to these lunges, whales make their feeding call. The exact purpose of the call is not known, but research suggests that fish do know what it means. When the sound was played back to them, a group of herring responded to the sound by moving away from the call, even though no whale was present.
- Prairie dog language: Dr. Slobodchikoff studied prairie dog communication and made the following discoveries. His current findings are that prairie dogs have:
- different alarm calls for different species of predators;
- different escape behaviors for different species of predators;
- transmission of semantic information, in that playbacks of alarm calls in the absence of predators lead to escape behaviors that are appropriate to the kind of predator who elicited the alarm calls;
- alarm calls containing descriptive information about the general size, color, and speed of travel of the predator. Northern Arizona University Research
- Caribbean Reef Squid have been shown to communicate using a variety of color, shape, and texture changes. Squid are capable of rapid changes in skin color and pattern through nervous control of chromatophores. In addition to camoflauge and appearing larger in the face of a threat, squids use color, patterns, and flashing to communicate with one another in various courtship rituals. Caribbean Reef Squid can send one message via color patterns to a squid on their right, while they send another message to a squid on their left.
Comparison of the term with "animal communication"
It is worth distinguishing "animal language" from "animal communication", no matter how complex that latter may be. In general the term "animal language" is reserved for the modeling of human language in animal systems, although there is some comparative interchange in certain cases (e.g. Cheney & Seyfarth's vervet monkey
call studies). Thus "animal language" typically does not include bee dancing, bird song, whale song, dolphin signature whistles, prairie dogs, nor the communicative systems found in most social mammals. Also the features of language as listed above are a dated formulation by Hockett in 1960, one of the first attempts ever to break down features of human language for the purpose of being able to apply Darwinian gradualism, and although an influence on early animal language efforts (see below), is today not considered the key architecture at the core of "animal language" research.
Also, Animal Language results are controversial for several reasons. (For a related controversy, see also Clever Hans.) In the 1970s John Lilly was attempting to "break the code" to speak full-out with wild populations of dolphins so we could speak to them, and share our cultures, histories, and more. This effort failed. The very early chimpanzee work was with chimpanzee infants raised as if they were human, a test of the nature vs. nurture hypothesis. Of course, they had a different laryngeal structure, as well as no voluntary control of their breathing, so this didn't work well, leading subsequent researchers to move toward a gestural (sign language) modality, as well as "keyboard" devices laden with buttons adorned with symbols (known as lexigrams) that the animals could push to produce artificial language, or observe humans pushing to comprehend it. These later keyboard and gestural chimpanzee researchers are perhaps the best known in animal language, and their animals are also known on a first-name basis: Sarah, Lana, Kanzi, Koko, Sherman, Austin, Chantek.
Perhaps the best known critic of "Animal Language" is Herbert Terrace. Terrace's 1979 criticism using his own research with the chimpanzee Nim Chimpsky was scathing and basically spelled the end of animal language research in that era, most of which emphasized the production of language by animals. In short, he accused researchers of over-interpreting their results, especially as it is rarely parsimonious to ascribe true intentional "language production" when other simpler explanations for the behaviors (gestural hand signs) could be put forth. Also, his animals failed to show generalization of the concept of reference between the modalities of comprehension and production; this generalization is one of many fundamental ones that are trivial for human language use. The simpler explanation according to Terrace was that the animals had learned a sophisticated series of context-based behavioral strategies to obtain either primary (food) or social reinforcement, behaviors that could be over-interpreted as language use.
In 1984 during this anti-Animal Language backlash, Louis Herman published an account of artificial language in the bottlenosed dolphin in the human journal Cognition. A major difference between Herman's work and previous research was his emphasis on a method of studying language comprehension only (rather than language comprehension and production by the animal(s)), which enabled rigorous controls and statistical tests, largely due to the fact that he was limiting his researchers to evaluating the animals' physical behaviors (in response to sentences) with blinded observers, rather than attempting to interpret possible language utterances or productions. The dolphins' names here were Akeakamai and Phoenix. Irene Pepperberg used the vocal modality for language production and comprehension in an African Grey Parrot named Alex in the verbal mode, and Sue Savage-Rumbaugh continues to study Bonobos such as Kanzi and Panbanisha. R. Schusterman duplicated many of the dolphin results in his California Sea Lions ("Rocky"), and came from a more behaviorist tradition than Herman's cognitive approach. Schusterman's emphasis is on the importance on a learning structure known as "equivalence classes."
However, overall, there has not been any meaningful dialog between the linguistics and animal language spheres, despite capturing the public's imagination in the popular press. Also, the growing field of language evolution is another source of future interchange between these disciplines. Most primate researchers tend to show a bias toward a shared pre-linguistic ability between humans and chimpanzees, dating back to a common ancestor, while dolphin and parrot researchers stress the general cognitive principles underlying these abilities. More recent related controversies regarding animal abilities include the closely linked areas of Theory of mind, Imitation (e.g. Nehaniv & Dautenhahn, 2002), Animal Culture (e.g. Rendell & Whitehead, 2001), and Language Evolution (e.g. Christiansen & Kirby, 2003).
Selected References from Primate, Parrot, Marine Mammal animal language programs, as well as the Linguistics literature:
- Bickerton, D. (2005). Language evolution: a brief guide for linguists. link
- Chomsky, N. (1957). Syntactic Structures. The Hague: Mouton. Reprint. Berlin and New York (1985).
- Chomsky, N. (1959). A Review of B.F. Skinner’s Verbal Behavior. Language, 35, 26-58.
- Chomsky, N. (1965). Aspects of the Theory of Syntax. Cambridge: The MIT Press.
- Chomsky, N. (1995). The minimalist program. Cambridge, MA: MIT Press.
- Chomsky, N. & Lasnik, H. (1993). The theory of principles and parameters, in: J. Jacobs A. von Stechow, W. Sternefeld, and T. Vennemann (eds.) Syntax: an international handbook of contemporary research. Berlin: De Gruyter.
- Christiansen, M.H. & Kirby, S.H. (Eds.)(2003). Language Evolution: The States of the Art. Oxford: Oxford University Press.
- Deacon, T. W. (1997) The Symbolic Species: The Co-evolution of Language and the Human Brain. Allen Lane: The Penguin Press.
- Fitch, W.T., & Hauser, M.D. (2004). Computational constraints on syntactic processing in a nonhuman primate. Science, 303, 377-380.
- Fouts, R. S. (1973). Acquisition and testing of gestural signs in four young chimpanzees. Science, 180, 978-80.
- Gardner, R.A., & Gardner, B.T. (1969). Teaching sign language to a chimpanzee. Science, 165, 664-672.
- Gardner, B.T., & Gardner, R.A. (1975). Evidence for sentence constituents in the early utterances of child and chimpanzee. Journal of Experimental Psychology: General, 104, 244-267.
- Gardner R. Allen and Gardner Beatrice T. (1980) Comparative psychology and language acquisition. In Thomas A. Sebok and Jean-Umiker-Sebok (eds.): Speaking of Apes: A Critical Anthology of Two-Way Communication with Man. New York: Plenum Press, pp.287-329.
- Gisiner, R., & Schusterman, R. J. (1992). Sequence, syntax, and semantics: Responses of a language-trained sea lion (Zalophus californianus) to novel sign combinations. Journal of Comparative Psychology, 106, 78.
- Gomez, R.L, & Gerken, L. (2000). Infant artificial language learning and language acquisition. Trends in Cognitive Sciences, 4, 178-186.
- Goodall, J. (1964). Tool Using and Aimed Throwing in a Community of Free-Living Chimpanzees, Nature, 201, 1264-1266.
- Hauser, M.D., Chomsky, N. & Fitch, W.T. (2002). The faculty of language: what is it, who has it, and how did it evolve? Science, 298, 1569-1579.
- Hayes, C. (1951). The Ape in Our House. New York: Harper & Row.
- Herman, L. M. & Forestell, P. H. (1985). Reporting presence or absence of named objects by a language-trained dolphin. Neuroscience and Biobehavioral Reviews, 9, 667-691.
- Herman, L. M. Kuczaj, S. A. & Holder, M. D. (1993). Responses to anomalous gestural sequences by a language-trained dolphin: Evidence for processing of semantic relations and syntactic information. Journal of Experimental Psychology: General 122 (2):184-194.
- Herman, L. M., Richards, D. G. & Wolz, J. P. (1984). Comprehension of sentences by bottlenosed dolphins. Cognition, 16, 129-219.
- Hockett, C. (1960).The origin of speech. Scientific American, 203, 88-96.
- Holder, M. D., Herman, L. M. & Kuczaj, S. III (1993). A bottlenosed dolphin's responses to anomalous gestural sequences expressed within an artificial gestural language. In H. R. Roitblat, L. M. Herman & P.E. Nachtigall (Eds): Language and Communication: Comparative Perspectives, 299-308. Hillsdale, NJ: Lawrence Erlbaum.
- Hurford J.R., Studdert-Kennedy, M., & Knight, C. (Eds.) (1998) Approaches to the evolution of language: Social and cognitive bases. Cambridge: Cambridge University Press.
- Kako, E. (1999). Elements of syntax in the systems of three language-trained animals. Animal Learning & Behavior, 27, 1-14.
- Kellogg, W.N., & Kellogg, L.A. (1933). The ape and the child. New York: Whittlesey House (McGraw-Hill).
- Knight, C., Studdert-Kennedy, M., Hurford, J.R. (Eds.) (2000). The evolutionary emergence of language: Social function and the origins of linguistic form. Cambridge: Cambridge University Press.
- Kohts. N. (1935). Infant ape and human child. Museum Darwinianum, Moscow.
- Ladygina-Kohts, N.N, & de Waal, F.B.M. (2002). Infant Chimpanzee and Human Child: A Classic 1935 Comparative Study of Ape Emotions and Intelligence (Tr: B. Vekker). New York: Oxford University Press.
- Lenneberg, E.H. (1971) Of language, knowledge, apes, and brains. Journal of Psycholinguistic Research, 1, 1-29.
- 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.
- Nehaniv C. & Dautenhahn, K.(Eds.) (2002). Imitation in Animals and Artifacts. Cambridge, MA.: MIT Press.
- Patterson, F., and Linden, E. (1981) The Education of Koko. New York: Holt, Rinehart and Winston.
- Pepperberg, I.M. (1999). The Alex Studies: Cognitive and Communicative abilities of Grey Parrots. Cambridge, MA: Harvard University Press.
- Pinker, S. (1984). Language Learnability and Language Development. Cambridge, MA: Harvard University Press. Reprinted in 1996 with additional commentary.
- Pinker, S. (1994). The language instinct: how the mind creates language. New York: William Morrow & Co.
- Pinker, S. & Bloom, P. (1990). Natural language and natural selection. Behavioral and Brain Sciences, 13, 707-784.
- Plooij, F.X. (1978). "Some basic traits of language in wild chimpanzees?" in A. Lock (ed.) Action, Gesture and Symbol. New York: Academic Press.
- Premack, D. (1971). Language in a chimpanzee? Science, 172, 808-822.
- Rendell, L. & Whitehead, H. (2001) Culture in whales and dolphins. Beharioral and Brain Sciences, 24, 309-382.
- Roitblat, H.R., Herman, L.M. & Nachtigall, P.E. (Eds.)(1993). Language and Communication: Comparative Perspectives, 299-308. Hillsdale, NJ: Lawrence Erlbaum.
- Rumbaugh Duane M. (1980) Language behavior of apes. In Thomas A. Sebok and Jean-Umiker-Sebok(eds.): Speaking of Apes: A Critical Anthology of Two- Way Communication with Man. New York: Plenum Press, pp.231-259.
- Savage-Rumbaugh, E. S. (1990). Language Acquisition in a Nonhuman Species: Implications for the innateness debate. Developmental Psychobiology, 23, 599-620.
- Savage-Rumbaugh, E.S., McDonald, K., Sevcik, R.A., Hopkins, W.D. & Rupert E, (1986). Spontaneous symbol acquisition and communicative use by pygmy chimpanzees (Pan paniscus). Journal of Experimental Psychology:General, 115, 211-235.
- Savage-Rumbaugh, E. S. and Fields, W. M. (2000). Linguistic, cultural and cognitive capacities of bonobos (Pan paniscus). Culture and Psychology, 6, 131-154.
- Sayigh, L.S., Tyack, P.L., Wells, R.S. & Scott, M.D. (1990). Signature whistles of free-ranging bottlenose dolphins (Tursiops truncatus): stability and mother-offspring comparisons. Behavioural Ecology and Sociobiology,247-260.
- Schusterman, R. J. & Gisiner, R. (1988). Artificial language comprehension in dolphins and sea lions: The essential cognitive skills. The Psychological Record, 34, 3-23.
- Schusterman, R.J. & Gisiner, R. (1989). Please parse the sentence: animal cognition in the Procrustean bed of linguistics. Psychological Record, 39:3-18.
- Schusterman, R. J. and Kastak, D. (1993) A California Sea-Lion (Zalaphos californianus) is capable of forming equivalence relations. The Psychological Record, 43, 823-839
- Schusterman, R. J. & Krieger, K. (1984). California sea lions are capable of semantic comprehension. The Psychological Record, 38, 311-348.
- Seyfarth, R. M. & Cheney, D.L. (1990). The assessment by vervet monkeys of their own and other species’ alarm calls. Animal Behavior, 40, 754-764.
- Skinner, B.F. (1957). Verbal behavior. Englewood Cliffs, NJ: Prentice-Hall.
- Terrace, H. S. (1979). Nim. New York: Knopf.
- Terrace H.S., Petitto L.A. , Sanders R.J. and Bever T.G. (1979) Can an ape create a sentence? Science 206:891-902.
- Wittmann, Henri (1991). "Classification linguistique des langues signées non vocalement." Revue québécoise de linguistique théorique et appliquée 10:1.215-88.