Serial gesturing by wild chimpanzees: its nature and function for communication

Abstract

Chimpanzees at Budongo, Uganda, regularly gesture in series, including 'bouts' of gesturing that include response waiting and 'sequences' of rapid-fire gesturing without pauses. We examined the distribution and correlates of 723 sequences and 504 bouts for clues to the function of multigesture series. Gesturing by older chimpanzees was more likely to be successful, but the success rate of any particular gesture did not vary with signaller age. Rather, older individuals were more likely to choose successful gestures, and these highly successful gestures were more often used singly. These patterns explain why bouts were recorded most in younger animals, whereas older chimpanzees relied more on single gestures: bouts are best interpreted as a consequence of persistence in the face of failure. When at least one gesture of a successful type occurred in a sequence, that sequence was more likely to be successful; overall, however, sequences were less successful than single gestures. We suggest that young chimpanzees use sequences as a 'fail-safe' strategy: because they have the innate potential to produce a large and redundant repertoire of gestures but lack knowledge of which of them would be most efficient. Using sequences increases the chance of giving one effective gesture and also allows users to learn the most effective types. As they do so, they need to use sequences less; sequences may remain important for subtle interpersonal adjustment, especially in play. This 'Repertoire Tuning' hypothesis explains a number of results previously reported from chimpanzee gesturing.

Nonhuman Primate Communication, Pragmatics, and the Origins of Language

“…Others have recently taken issue with this claim. The argument raised is that if the gestures were ontogenetically ritualized, then the actions involved should closely match those of the presumed original actions, but detailed analyses of great ape gestures suggest that this is not the case (Genty et al 2009;Hobaiter and Byrne 2011a). The authors of these analyses thus argue that most gestures are part of a speciestypical repertoire (Genty et al 2009;Hobaiter and Byrne 2011a).…”

“…The argument raised is that if the gestures were ontogenetically ritualized, then the actions involved should closely match those of the presumed original actions, but detailed analyses of great ape gestures suggest that this is not the case (Genty et al 2009;Hobaiter and Byrne 2011a). The authors of these analyses thus argue that most gestures are part of a speciestypical repertoire (Genty et al 2009;Hobaiter and Byrne 2011a). Debate continues: those who advocate the ontogenetic ritualization hypothesis have recently produced new analyses in which they track the process of ontogenetic ritualization over time and hence show that it is responsible for the creation of at least some great ape gestures (Halina, Rossano, and Tomasello 2013).…”

Dyadic brain modelling, mirror systems and the ontogenetic ritualization of ape gesture

“…This includes sensitivity to audience comprehension and invoking 'semantically related' gestures if comprehension fails [4], gesturing in sequence bouts [5] and 'complex' forms of gesturing [48], suggesting that 'iconic' gestures may be used in gorilla populations. Note also the suggestion that 'pantomime' may be used by orangutans to demonstrate complex notions [49]-though this seems to be more a matter of creating a few iconic gestures than a general capacity for pantomime as a means to create an open-ended set of novel gestures.…”

“…However, a few group-specific gestures have been observed in ape populations, suggesting a role for social learning [3]. Gestural behaviour is contextualized by the comprehension and attentional states of others, and failed gestural communicative attempts often result in production of a series of semantically similar gestures [4][5][6]. We do not review the broad literature on ape gestural production and comprehension here, but reviews can be found elsewhere [3,[7][8][9] and in the paper [10] to which this is the sequel.…”

Where Apes and Songbirds are Left Behind: A Comparative Assessment of the Requisites for Speech

“…Gestures by captive chimpanzees and bonobos (Pollick & de Waal, 2007), as well as wild chimpanzees (Hobaiter & Bryne, 2011a, 2011b, appear to be more diverse and flexibly used than the vocal calls used by the species. As Pollick and de Waal (2007) reported, apes' gestural repertoires were larger than their repertoires of facial/vocal signals.…”