A STUDY OF SIGN LANGUAGE IN ClUMP ANZEES (original) (raw)
Hand use and gestural communication in chimpanzees (Pan troglodytes)
Journal of Comparative Psychology, 1998
Hand use in gestural communication was examined in 115 captive chimpanzees (Pan troglodytes). Hand use was measured in subjects while they gestured to food placed out of their reach. The distribution of hand use was examined in relation to sex, age, rearing history, gesture type, and whether the subjects vocalized while gesturing. Overall, significantly more chimpanzees, especially females and adults, gestured with their right than with their left hand. Foods begs were more lateralized to the right hand than pointing, and a greater prevalence of right-hand gesturing was found in subjects who simultaneously vocalized than those who did not. Taken together, these data suggest that referential, intentional communicative behaviors, in the form of gestures, are lateralized to the left hemisphere in chimpanzees.
The Meanings of Chimpanzee Gestures - Hobaiter et al
Chimpanzees' use of gesture was described in the first detailed field study , and natural use of specific gestures has been analyzed . However, it was systematic work with captive groups that revealed compelling evidence that chimpanzees use gestures to communicate in a flexible, goal-oriented, and intentional fashion , replicated across all great ape species in captivity [9-17] and chimpanzees in the wild . All of these aspects overlap with human language but are apparently missing in most animal communication systems, including great ape vocalization, where extensive study has produced meager evidence for intentional use ([20], but see ). Findings about great ape gestures spurred interest in a potential common ancestral origin with components of human language . Of particular interest, given the relevance to language origins, is the question of what chimpanzees intend their gestures to mean; surprisingly, the matter of what the intentional signals are used to achieve has been largely neglected. Here we present the first systematic study of meaning in chimpanzee gestural communication. Individual gestures have specific meanings, independently of signaler identity, and we provide a partial ''lexicon''; flexibility is predominantly in the use of multiple gestures for a specific meaning. We distinguish a range of meanings, from simple requests associated with just a few gestures to broader social negotiation associated with a wider range of gesture types. Access to a range of alternatives may increase communicative subtlety during important social negotiations.
Chimpanzee language research: Status and potential
Behavior Research Methods & Instrumentation, 1978
monkey's innovations of washing sand from potatoes and of using tidal pools to separate, by flotation, wheat from sand, and the transmissions thereof through vectors of social communication have served to tarnish that brass tenet (Azuma, 1973). Now the ape-language projects of the past decade serve to question the conclusion that man alone is capable of language. Language might yet prove to be the eternal bastion for man's egocentric need to define himself as distinctively unique from other animals: He alone normally acquires language, and notably speech, through the normal course of his development. The walls and plaster of the bastion have been seen to shower a bit of dust here and there, however, and to give evidence of perhaps even a crack or two through the course of recent years, for there is mounting evidence that although language per se might be unique to man, not all the requisites thereto are unique to man: Given systematic exposure to nonspeech linguistic alternatives that are marked by "openness," great apes (Pan and Gorilla, notably) have mastered the rudiments of language. The "openness" that characterizes human natural languages stands in marked contrast to all known descriptions of animal communication systems. So far as has been determined, no animal form in its
Ape gestures and language evolution.pdf
The natural communication of apes may hold clues about language origins, especially because apes frequently gesture with limbs and hands, a mode of communication thought to have been the starting point of human language evolution. The present study aimed to contrast brachiomanual gestures with orofacial movements and vocalizations in the natural communication of our closest primate relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). We tested whether gesture is the more flexible form of communication by measuring the strength of association between signals and specific behavioral contexts, comparing groups of both the same and different ape species. Subjects were two captive bonobo groups, a total of 13 individuals, and two captive chimpanzee groups, a total of 34 individuals. The study distinguished 31 manual gestures and 18 facial/vocal signals. It was found that homologous facial/vocal displays were used very similarly by both ape species, yet the same did not apply to gestures. Both within and between species gesture usage varied enormously. Moreover, bonobos showed greater flexibility in this regard than chimpanzees and were also the only species in which multimodal communication (i.e., combinations of gestures and facial/vocal signals) added to behavioral impact on the recipient.
The repertoire and intentionality of gestural communication in wild chimpanzees
2014
A growing body of evidence suggests that human language may have emerged primarily in the gestural rather than vocal domain, and that studying gestural communication in great apes is crucial to understanding language evolution. Although manual and bodily gestures are considered distinct at a neural level, there has been very limited consideration of potential differences at a behavioural level. In this study, we conducted naturalistic observations of adult wild East African chimpanzees (Pan troglodytes schweinfurthii) in order to establish a repertoire of gestures, and examine intentionality of gesture production, use and comprehension, comparing across manual and bodily gestures. At the population level, 120 distinct gesture types were identified, consisting of 65 manual gestures and 55 bodily gestures. Both bodily and manual gestures were used intentionally and effectively to attain specific goals, by signallers who were sensitive to recipient attention. However, manual gestures differed from bodily gestures in terms of communicative persistence, indicating a qualitatively different form of behavioural flexibility in achieving goals. Both repertoire size and frequency of manual gesturing were more affiliative than bodily gestures, while bodily gestures were more antagonistic. These results indicate that manual gestures may have played a significant role in the emergence of increased flexibility in great ape communication and social bonding.
Spontaneous symbol acquisition and communicative use by pygmy chimpanzees (< em> Pan paniscus)
Journal of …, 1986
Two pygmy champanzees (Pan paniscus) have spontaneously begun to use symbols to communicate with people. In contrast to common chimpanzees (Pan troglodytes) using the same communicative system, the pygmy chimpanzees did not need explicit training in order to form referential symbolobject associations. Instead, they acquired symbols by observing others use these symbols in daily communications with them. In addition, the pygmy chimpanzees have begun to comprehend spoken English words and can readily identify lexigrams upon hearing the spoken words. By contrast, common chimpanzees who received similar exposure to spoken English are unable to do so. The older pygmy chimpanzee has begun to form requests of the form agent-verb-recipient in which he is neither the agent nor the recipient. By contrast, similarly aged common chimpanzees limited their requests to simple verbs, in wihch the agent was always presumed to be the addressee and the chimpanzee itself was always the recipient, thus they had no need to indicate a specific agent or recipient. These results suggest that these pygmy chimpanzees exhibit symbolic and auditory perceptual skills that are distinctly different from those of common chimpanzees. What's in a Name? The language acquisition capacity of apes has been the focus of a number of research projects (Asano, Kojima, Matsuzawa,
Language & Communication, 2011
While numerous publications have shown that apes can learn some aspects of human language, one frequently cited difference between humans and apes is the relative infrequency of declaratives (comments and statements) as opposed to imperatives (requests) in ape symbol use. This paper describes the use of declaratives in three language-competent apes and two children. The apes produced a lower proportion of spontaneous declaratives than did the children. However, both groups used declaratives to name objects, to interact and negotiate, and to make comments about other individuals. Both apes and children also made comments about past and future events. However, showing/offering/giving, attention getting, and comments on possession were declarative types made by the children but rarely by the apes.