Language And Animal Competencies Research Paper

At least one notable scholar of human language has asserted, in a recent lecture, that the question, ‘Do animals have language?’ is not scientific (Pinker 1999). Why? Because language cannot be defined to everyone’s satisfaction. By that token, of course, then no one (and certainly not the scholar of reference) should assert that animals do not have language. The fact is that definitions of constructs (e.g., personality, learning, thinking, intelligence, language, etc.) can never be honed to everyone’s satisfaction. Notwithstanding, definitions of terms are necessary to science.

Here, our working definition is that

language is a biobehavioral system that provides for the learning of meanings of symbols and for their use to exchange information within a social context. Symbols may be based in any modality—sound (e.g. speech, hearing, drumming, whistling, etc.), vision (e.g. writing, geometric figures, movements with hands and body, etc.), touch (e.g. Braille), and so on.

It is meaningfulness that differentiates symbols words from other stimuli. The meanings of words (e.g., semantics) are the result of social usage, hence the meanings of words are subject to radical change across time. The language system is open in that new words may be added and old words deleted. The language system also provides for the generation of novel messages through the interactive use of words (e.g., rules of grammar and syntax provide for ‘I’m buying a house dog’ to differ radically in meaning from ‘I’m buying a dog house,’ though the words used remain constant). The ability to comprehend language is an absolute requisite to competence in productive use expressions of language. Hence, the first essential process of language acquisition by the human child is comprehension, that is, understanding language used by others. Later, the child typically begins to use/produce that language through speech and gesture.

The following review of animal language research, conducted over the course of the past half-century, documents that language is a continuum, a highly complex biobehavioral system that is clearly traceable to animals, and notably to the great apes (Gardner et al. 1989, Premack 1970, Rumbaugh 1977, Fouts and Fouts 1989, Miles 1990, Savage-Rumbaugh and Lewin 1994), pinnipeds (Herman 1987, Schusterman et al. 1993), and parrots (Pepperberg 1990), all having demonstrated the ability to learn and use symbols with semantic competence (e.g., for symbols to acquire meaning and to represent things/events not necessarily present). The primary foundation of language is in the comprehension of speech or of the units of any other language system, and not in the production of speech. Because of its openness and generativity (e.g., to the addition of new word-symbols and to the modulation of their meanings through social commerce), language should not be viewed as or called an instinct (e.g., unlearned, highly predictable expression of genetically defined behaviors, synchronized and expressed through the course of biological development and maturation). The acquisition of language, whether by the human child or ape, is highly contingent on specific aspects of early rearing; and apes, if reared from birth in a language-structured environment (e.g., one in which language is used throughout all dimensions of their rearing experiences to the end of encouraging their comprehension and anticipation of all events), can understand hundreds of novel sentences of request that they hear even for the first occasion in tightly controlled research procedures. Formal training procedures, based on stimulus–response–reinforcement, used to cultivate language competence in animals are less effective than appropriate social/language rearing to the cultivation of language and notably to the ability to comprehend human speech. Apes can use their language skills to coordinate problem solving, either between themselves or with caregivers, that otherwise would be impossible (Menzel 1999). Apes’ brains are lateralized both in structure and function, though the circuits systems used for language might not, in detail, be identical to ours in language acquisition and use (Rilling et al. 1999).

1. Language Acquisition In Animals

Research by Keith and Cathy Hayes (Hayes and Nissen 1971) clearly demonstrated that chimpanzees could not speak with any significant facility and that if they had any potential for language, another medium of expression would have to be developed in order to study it. Allen and Beatrix Gardner (1969) used a modification of the American Sign Language for the Deaf, a manual and gestural language system of a kind that Yerkes and Learned (1925) suggested might be fruitful for the study of apes’ language potential. Manual signing systems were also used by Miles (1990) and Terrace (1979). Premack (1971) used a set of plastic tokens as units of a vocabulary and made significant contributions to defining the essence of words.

Rumbaugh’s (1977) group succeeded in developing a computer-monitored keyboard and system with which the chimpanzee, Lana, became very proficient in learning ‘stock sentences of request’ that were effective in obtaining food (i.e., Please machine give piece of banana), viewings of movies, slides, and the outdoors (i.e., Please machine make window open), and special human companionship and other privileges (i.e., Please Tim tickle Lana). All keys of her keyboard were embossed with distinctive lexigrams that functioned as words—hence they are termed ‘word-lexigrams.’ Lana’s many accomplishments included the learning of names of six colors and six objects (with each object being painted each of the six colors, for a total of 36 items), with which she could give, upon request, either the color or the name of a designated object from a set of several objects. For instance, with a random array of the objects displayed to her, she could accurately answer questions, such as ‘What name of this that’s (red, green, etc.)?’ vs. ‘What color of this shoe?’

Somewhat later, chimpanzees Sherman and Austin (Savage-Rumbaugh 1986) learned functionally how to use lexigrams in order to make requests for specific items. Eventually it was clear that for them their lexigrams actually represented the items that they had earlier simply requested. This conclusion was based on their near errorless ability to classify via two lexigrams, one standing for ‘food’ and the other for ‘tool,’ each of 17 lexigrams on a trial-1 basis in a controlled test. With these basic skills of using lexigrams to request items or to name them, they then were able to move on to a number of remarkable interactions that entailed their coordinated communications and behaviors to solve problems that netted prized incentives for them and, also, to announce what it was that they were about to do—to announce which item it would be that they would retrieve from a random set of foods and drinks (Savage-Rumbaugh 1986).

An even more significant finding was obtained in work with bonobos, a rare form of chimpanzee (Pan paniscus). Sue Savage-Rumbaugh and her colleagues (Savage-Rumbaugh et al. 1993, Savage-Rumbaugh and Lewin 1994) worked with Matata, a bonobo, with training methods that had worked so well with Sherman and Austin (common chimpanzees, P. troglodytes). With Matata, however, they had almost no success. Serendipitously, however, it was discovered that Matata’s adopted son, Kanzi, who as an infant only observed Matata’s training situation, had spontaneously learned (e.g., without formal training) it all! It was only when Matata was separated from him, when he was 2 years old, that his learning became manifest. Then, at his own initiative, he formulated novel requests, announced intended actions, and proposed games that were not even part of Matata’s sessions. By age four years, he understood several dozen spoken words. His learning as an infant was noted for its ‘silence’ in that his behaviors had given no indication to the researchers that he was mastering such complex relationships and language skills. By age four years, Kanzi was competently understanding and using lexigrams with his caregivers and, quite unexpectedly, gave evidence of understanding much of his caregivers’ spoken English. Formal tests revealed that he knew the referents meanings of at least 150 spoken words.

Kanzi’s accomplishments go well beyond the highly significant fact that by observation alone he learned his initial lexicon (Savage-Rumbaugh and Lewin 1994, Savage-Rumbaugh et al. 1998) and also eventually came to understand spoken English words. Although there have been long-standing assertions that an ape, here and there, ‘understands’ a few English words, none began to equal Kanzi’s understanding of hundreds of words—not just individual words, but novel sentences of request as w ell. Kanzi, age seven years, was tested with Alia, a 2 -year-old child, with 660 novel sentences (e.g., neither familiar, trained, or modeled by others). Some requested that they act in reference to places, persons, and materials, while others called for them to act with reference to objects and locations (Savage-Rumbaugh et al. 1993)—‘Take the gorilla (doll) to the bedroom’; ‘Give Karen a carrot,’ ‘Take the vacuum cleaner outdoors,’ ‘Hammer the snake,’ or ‘Get the lettuce that’s in the microwave oven,’ and so on.

In addition, there were a variety of requests that entailed reversals such as ‘Make the doggie bite the snake,’ vs. ‘Make the snake bite the doggie.’ Alia and Kanzi promptly fulfilled about 70 percent of the novel requests upon their first presentation. On reversal requests, Kanzi was 81 percent correct, whereas Alia was 64 percent correct.

Kanzi’s remarkable achievements, traceable to his early rearing, are in sharp contrast to the devastating effect that impoverished rearing during early infancy has upon the cognitive and social competence of common chimpanzees. If their rearing environments (e.g., the first two years or so) are sorely limited and socially impoverished, they never fully recover. They remain both cognitively and socially compromised (e.g., poor at breeding, parenting, and social communication commerce), even when tested at age 14 years as young adults (Davenport et al. 1973). Primates’ general social and cognitive competence are very dependent on their early environment. The same is true for the human child.

Significant research has also been reported with a parrot. Pepperberg (1990) trained Alex, an African gray parrot, using what she called the ‘model-rival’ method. Here, Alex observed linguistic interactions between two people who served as ‘models’ and ‘rivals.’ The model rivals talked about and exchanged objects of interest to Alex. Alex entered the conversation at will and eventually was highly skilled in asking for, choosing, or describing the color, shape, and materials of the objects with which he was familiar. For both Kanzi and Alex, the language acquisition contexts were designed to encourage spontaneous responding and designed such that uses of words were efficacious. Typical classical or operant conditioning experiments have emphasized the mastery of a single response in a specific context. By contrast, the training contexts for Kanzi and for Alex drew upon a great variety of different lexical responses.

The data of these projects and successful replications thereof (Brakke and Savage-Rumbaugh 1995, 1996, Savage-Rumbaugh et al. 1998, Pepperberg 1999) have had major affects upon how we now should view animals’ abilities.

2. Tool Making By Observational Learning

Kanzi also learned by observation how to make and use stone tools to gain access to baited food sites. Kanzi was never trained to create the flakes in any specific manner. His model was an anthropologist, Nick Toth, who created stone flakes through striking two rocks together (Savage-Rumbaugh and Lewin 1994, Toth et al. 1993). Over time, Kanzi acquired skill both in creating stone flakes and evaluating their probable effectiveness for cutting ropes of varying thickness. As a tool lost its cutting edge, Kanzi would make a new, more effective one. Kanzi’s causal understanding of tool fabrication and use was demonstrated in three very impressive ways. Early in his efforts, he innovatively started to throw one rock on to a hard surface or on to another rock on the ground. Thus, Kanzi first appeared to understand that it was the fundamental force of one rock striking another that created the flakes. Second, he rapidly learned how to assess whether a given flake would be sufficient to the task at hand—be it to cut a rope or a piece of leather. Inadequate chips were discarded and replaced with new ones as needed. Third, eventually Kanzi came to hold the cobble so as to hit it on an edge of less than 90 degrees, thereby producing large and very sharp chips of flint.

3. Language And Inferences Of Causality

There is evidence that language serves to make animals more competent in general—as though they understand more readily cause–effect relationships and how things work (Michotte 1963, Piaget 1930, 1974). For instance, Kanzi quickly learned, by brief observation, how to use a joystick to control the movement of a cursor-icon on a monitor and to play video games, including PacMan. Earlier, both Sherman and Austin had quickly learned the use of a joystick, again as a result of a brief demonstration ( 15 min) (SavageRumbaugh 1986, Savage-Rumbaugh and Lewin 1994). We had anticipated that they would have great trouble in learning to use the joystick (Rumbaugh et al. 1989) and were surprised that they learned so quickly and by observation alone. They seemingly saw understood ‘how it worked’ very readily and what was to be gained by using it with precision. By striking contrast, apes with little or no language skills from our laboratory have generally required either protracted operant training or months of observing a competent cohort.

4. Cooperation Enabled By Symbolic Communication

Savage-Rumbaugh’s (1986) project with Sherman and Austin was designed to cultivate symbolic communication so as to coordinate problem-solving efforts. After considerable training on a variety of tasks, the apes became quite accomplished in their cooperative efforts. For example, one of the chimpanzees could observe food being placed in a container that required a specific tool for opening it—a requisite to getting the prized incentive within. The other chimpanzee was not allowed to watch the placement of the food into a secured container, and, thus, did not know what tool was needed. Tools needed varied with containers and included a lever, key, a sponge, a cord, and so on. The chimpanzee who saw the food secured thus could infer what tool would be needed. A request by that chimpanzee was then made of the other one to supply it with a tool, specified by selection of the appropriate word-lexigrams at the keyboard that contained more than 100 symbols. If the symbol-encoded request was fulfilled, then the chimpanzee receiving it used the tool to open the secured container. The incentive, thus obtained, was then shared with the chimpanzee who complied with the tool-users’ request. Both chimpanzees were competent in both tasks—asking for and vending the tool as specified across trials. The knowledge base with which they coordinated their efforts was documented on the several occasions on which Austin by mistake gave Sherman an incorrect tool (e.g., not the one requested). On those occasions, Sherman would throw the tool down (e.g., reject it) and then bring Austin’s attention once again, via the lexigrams keyboard, to the name of the tool that had been requested and needed for the incentive to be obtained.

Clearly, this task could be solved only by social communication through the use of learned symbols. Savage-Rumbaugh (1986; also Savage-Rumbaugh et al. 1998) reports many other strong instances of goal- directed communication. For instance, when Sherman and Austin spontaneously used labels from food cans and boxes to communicate when their keyboard was denied to them (e.g., turned off) and also when Kanzi and others helped novice research assistants find wordlexigrams that they were having difficulty finding for their own use on the keyboard.

For these and other reasons, we believe it constructive to add the category of emergents to the traditional dichotomy of learning embraced by the traditional dichotomy of respondent and operant conditioning. Emergents are exemplified in the appearance of highly complex and even unanticipated competencies on the basis of protracted generalized, rather than specific, experiences and through observation (Rumbaugh et al. 1996).

5. Summary And Conclusions

At the dawn of a new millennium and consonant with Darwin’s postulate of psychological as well as biological continuity between humans and other animals, there is strong evidence that language should be viewed as a continuum (Deacon 1998), with its fundamental roots being firmly planted most clearly in apes—our nearest living relatives (Andrews and Martin 1987). This evidence, rooted in 50 years of dedicated effort measured in decades and careers of scientists and staff, is solid. It has survived countless peer reviews for funding and publication. Apes, pinnipeds, and parrots have potentials for language skills that can be cultivated through early rearing and social exchanges. Yet there are a few influential scholars of note who, quite matter of factly, reveal at best only a limited understanding of the research or even total disinterest. They fail to recognize the evolutionary and neurobiological significance of the animal research and seemingly are satisfied to accept rhetoric in lieu of data and scientific reason. Yet, time surely will vindicate those who argue, from scientific data, that the evidence of animal species’ potential for language is of inestimable significance from the perspectives of science, philosophy, language, and public policy. For science, the data vindicates the Darwinian perspective of psychological continuity from animal to human, a continuity afforded by biological continuity (Andrews and Martin 1987). For philosophy, the data declare that human quality of life, thought, and culture need to be understood from a comparative perspective. For students of language, the data declare that the roots, primitive though they might be, for language and cognition are traceable to nonhuman genes (e.g., to animals). For public policy, the data declare that animals are not the mindless, senseless beast machines that Descartes declared them to be. Unique we humans are, to be certain; but then, so are all other species of life. More powerful than they we are, though whether we are more worthy merits reconsideration. At least some animals, notably the great apes, are not properly viewed as chattel, for they are sentient thoughtful beings, in measure. Their behaviors tell us of the evolutionary history of eons past of animals’ ground that they share in common with us.

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