The repertoire and intentionality of gestural communication in wild chimpanzees

Abstract

1A growing body of evidence suggests that human language may have emerged 2 primarily in the gestural rather than vocal domain, and that studying gestural communication

Social Brain Hypothesis: Vocal and Gesture Networks of Wild Chimpanzees

“…This seems to be determined not by inefficient foraging in larger groups or by predation risk, but directly by the inability of individuals to service social relationships in the face of the inevitably limited amount of time available for social interaction (Henzi et al, 1997). However, it is increasingly being recognized that in addition to grooming, vocalizations (sounds made with the vocal tract) and gestural communication (voluntary movements of the arm, hand, head, or whole body; Roberts et al, 2014a,b) may also play key roles in developing and maintaining social bonds in primates. Time constraints limit the amount of time available for grooming (Lehmann et al, 2007), but vocal and gestural signals are less constrained by time, and thus may offer an important additional way to regulate social relations in groups of primates.…”

“…These included a longer duration of visual attention directed at the dyad partner, a longer duration of mutual grooming and received grooming, and a longer duration of time spent resting and traveling, per hour the pair of chimpanzees spent in close proximity (within 10 m; Roberts and Roberts, 2016). Moreover, chimpanzees use a communication system consisting of gestures (Leavens et al, 2004; Forrester, 2008; Hobaiter and Byrne, 2011; Roberts et al, 2012a,b, 2013, 2014a; Smith and Delgado, 2013; Bard et al, 2014) and vocalizations to maintain their relationships (Van Lawick-Goodall, 1967, 1968; Goodall, 1986; Mitani and Nishida, 1993; Mitani et al, 1999; Roberts and Roberts, 2016). For instance, chimpanzees use visual gestures with strongly bonded individuals and tactile or auditory gestures with weakly bonded individuals (Roberts and Roberts, 2016).…”

“…For instance, chimpanzees use visual gestures with strongly bonded individuals and tactile or auditory gestures with weakly bonded individuals (Roberts and Roberts, 2016). Gestural communication that has previously been suggested to be important in relation to social bonds includes gestures made when encountering each other after a natural period of separation, in response to the threat of aggression or after receiving aggression (Roberts et al, 2014a; Taglialatela et al, 2015). Vocal communication hypothesized to be important in relation to social bonding in chimpanzees includes pant-hoot calls produced solo or jointly with group members in conjunction with visual or auditory gestures (Mitani and Nishida, 1993; Fedurek et al, 2013) and one-to-one calls (e.g., low intensity pant-grunt calls produced by a subordinate individual towards a dominant chimpanzee).…”

“…However, one-to-one communication still requires some degree of close proximity and one-to-one prior visual attention (Roberts et al, 2014a) or brief tactile contact and thus a relatively low number of individuals can be bonded with at any one time. Moreover, these interactions are cognitively complex because animals have to remember the identities of the interactants and their past and present relationships with them to bond in an efficient manner.…”

Insights into the Genetic Foundations of Human Communication

“…These primates are very limited in their range of vocalizations and ability to control and learn vocalizations, but chimpanzees in the wild use a basic repertoire of gestures for intentional communication in order to achieve goals (Hobaiter and Byrne 2014;Roberts et al 2014). Chimpanzees and bonobos in captivity are able to map meanings onto arbitrary symbols and use these for communication with humans and conspecifics, including communication about objects and events not in the here and now, pointing to a communicative capacity that is latent in the wild (Lyn et al 2014;Zuberbuhler 2014).…”