Red-capped mangabeys (Cercocebus torquatus) adapt their interspecific gestural communication to the recipient’s behaviour (original) (raw)

Intentional gestural communication amongst red-capped mangabeys (Cercocebus torquatus)

Animal Cognition, 2022

Apes, human’s closest living relatives, are renowned for their intentional and highly flexible use of gestural communication. In stark contrast, evidence for flexible and intentional gestural communication in monkeys is scarce. Here, we investigated the intentionality and flexibility of spontaneous gesture use in red-capped mangabeys (Cercocebus torquatus). We applied established methods used in ape gesture research to analyse whether the body acts produced by a total of 17 individuals living in three different groups in captivity qualified as intentionally produced gesture instances. Results showed that signallers showed all hallmarks of intentionality during the production of 20 out of a total of 21 different types of body acts. These were only produced in the presence of other individuals, and the monkeys showed audience checking, sensitivity to the attentional states of recipients, adjustment of signal modality, and response waiting relative to their production. Moreover, in cas...

Flexibility in the use of requesting gestures in squirrel monkeys (Saimiri sciureus)

American Journal of Primatology, 2010

Three squirrel monkeys, trained to make a requesting gesture, were tested in the presence of a human assistant whose visual attention varied across trials. When food was available in one dish and an empty dish was nearby, the monkeys pointed overwhelmingly toward the former, regardless of where the assistant was looking. Looking at the assistant while pointing (''monitoring'') peaked when she looked at them and when she attempted to engage them in joint attention. When only one dish was present, the monkeys refrained from gesturing if it was empty and if no assistant was present. They gestured more when the assistant made eye contact with them. Furthermore, when the assistant's focus of attention switched from the dish or the ceiling to the monkeys, the latter resumed pointing and increased their monitoring of the assistant. This is the first demonstration of such flexible use of an intentionally communicative requesting gesture in New World monkeys. Am.

Training experience in gestures affects the display of social gaze in baboons' communication with a human

Animal cognition, 2015

Gaze behaviour, notably the alternation of gaze between distal objects and social partners that accompanies primates' gestural communication is considered a standard indicator of intentionality. However, the developmental precursors of gaze behaviour in primates' communication are not well understood. Here, we capitalized on the training in gestures dispensed to olive baboons (Papio anubis) as a way of manipulating individual communicative experience with humans. We aimed to delineate the effects of such a training experience on gaze behaviour displayed by the monkeys in relation with gestural requests. Using a food-requesting paradigm, we compared subjects trained in requesting gestures (i.e. trained subjects) to naïve subjects (i.e. control subjects) for their occurrences of (1) gaze behaviour, (2) requesting gestures and temporal combination of gaze alternation with gestures. We found that training did not affect the frequencies of looking at the human's face, looking at food or alternating gaze. Hence, social gaze behaviour occurs independently from the amount of communicative experience with humans. However, trained baboons-gesturing more than control subjects-exhibited most gaze alternation combined with gestures, whereas control baboons did not. By reinforcing the display of gaze alternation along with gestures, we suggest that training may have served to enhance the communicative function of hand gestures. Finally, this study brings the first quantitative report of monkeys producing requesting gestures without explicit training by humans (controls). These results may open a window on the developmental mechanisms (i.e. incidental learning vs. training) underpinning gestural intentional communication in primates.

Olive baboons, Papio anubis, adjust their visual and auditory intentional gestures to the visual attention of others

Animal Behaviour, 2014

Keywords: audience attention gestural communication intentionality language nonhuman primate Although nonhuman primates' gestural communication is often considered to be a likely precursor of human language, the intentional properties in this communicative system have not yet been entirely elucidated. In particular, little is known about the intentional nature of monkeys' gestural signalling and related social understanding. We investigated whether olive baboons can (1) adjust their requesting gestures to the visual attention of the experimenter with special emphasis on the state of the eyes (open versus closed), and (2) flexibly tailor visual and auditory-based gestures to elaborate their communication as a function of whether or not the experimenter can see them. Using a food-requesting paradigm, we found monkeys able to favour either visual or auditory-based requesting gestures to match the experimenter's visual attention. Crucially, when the human was not visually attending, they silenced visual gestures to some extent but performed more attention-getting gestures. This is, to our knowledge, the first report of monkeys elaborating attention-getting signals to compensate for communication breakdown. Gestural communication was also supported by gaze alternation between the experimenter's face and the food, especially when the human was visually attending. These findings offer evidence that olive baboons understand the state of the eyes in others' visual attention and use requesting gestures intentionally. They emphasize that Old World monkeys shift to acoustic communication when the recipient is not visually attending. In contrast to that of human infants and great apes, this acoustic communication is purely gestural, not vocal. Ó

Gestural communication of apes

Gesture, 2005

Gestural communication of nonhuman primates may allow insight into the evolutionary scenario of human communication given the flexible use and learning of gestures as opposed to vocalizations. This paper provides an overview of the work on the gestural communication of apes with the focus on their repertoire, learning mechanisms, and the flexibility of gesture use during interactions with conspecifics. Although there is a variation between the species in the types and numbers of gestures performed, the influence of ecology, social structure and cognitive skills on their gestural repertoires is relatively restricted. As opposed to humans, apes do not use their gestures referentially nor do their gestures show the symbolic or conventionalized features of human gestural communication. However, since the gestural repertoires of apes are characterized by a high degree of individual variability and flexibility of use as opposed to their vocalizations it seems plausible that the gestures w...

Gestural communication in nonhuman and human primates

2007

Research into gestures represents a multifaceted field comprising a wide range of disciplines and research topics, varying methods and approaches, and even different species such as humans, apes and monkeys. The aim of this volume (originally published as a Special Issue of Gesture 5:1/2 (2005)) is to bring together the research in gestural communication in both nonhuman and human primates and to explore the potential of a comparative approach and its contribution to the question of an evolutionary scenario in which gestures play a significant role. The topics covered include the spontaneous natural gesture use in social groups of apes and monkeys, but also during interactions with humans, gestures of preverbal children and their interaction with language, speech-accompanying gestures in humans as well as the use of sign-language in human and nonhuman great apes. It addresses researchers with a background in Psychology, Primatology, Linguistics, and Anthropology, but it might also f...

The gestural communication of apes

2007

Benjamins Current Topics Volume 10 Gestural Communication in Nonhuman and Human Primates Edited by Katja Liebal, Cornelia Müller and Simone Pika These materials were previously published in Gesture 5:1/2 (2005) Special issues of established journals tend to circulate within the orbit of the subscribers of those journals. For the Benjamins Current Topics series a number of special issues have been selected containing salient topics of research with the aim to widen the readership and to give this interesting material an additional lease of life in book format.

Intentional communication by chimpanzees: A cross-sectional study of the use of referential gestures

Developmental Psychology, 1998

This study describes the use of referential gestures with concomitant gaze orienting behavior to both distal food objects and communicative interactants by 115 chimpanzees, ranging from 3 to 56 years of age. Gaze alternation between a banana and an experimenter was significantly associated with vocal and gestural communication. Pointing was the most common gesture elicited; 47 subjects pointed with the whole hand, whereas 6 subjects pointed with index fingers. Thus, communicative pointing is commonly used by laboratory chimpanzees, without explicit training to point, language training, or home rearing. Juveniles exhibited striking decrements in their propensity to communicate with adult male experimenters compared with older chimpanzees. Significantly fewer mother-reared chimpanzees exhibited gaze alternation compared with nursery-reared chimpanzees.

Intentional communication between wild bonnet macaques and humans

Scientific reports, 2018

Comparative studies of nonhuman communication systems could provide insights into the origins and evolution of a distinct dimension of human language: intentionality. Recent studies have provided evidence for intentional communication in different species but generally in captive settings. We report here a novel behaviour of food requesting from humans displayed by wild bonnet macaques Macaca radiata, an Old World cercopithecine primate, in the Bandipur National Park of southern India. Using both natural observations and field experiments, we examined four different behavioural components-coo-calls, hand-extension gesture, orientation, and monitoring behaviour-of food requesting for their conformity with the established criteria of intentional communication. Our results suggest that food requesting by bonnet macaques is potentially an intentionally produced behavioural strategy as all the food requesting behaviours except coo-calls qualify the criteria for intentionality. We comment...