Why do gorillas make sequences of gestures?

Scottish Primate Research Group, Centre for Social Learning and Cognitive Evolution, School of Psychology, University of St Andrews, Fife, Scotland, UK.
Animal Cognition (Impact Factor: 2.58). 09/2009; 13(2):287-301. DOI: 10.1007/s10071-009-0266-4
Source: PubMed


Great ape gestures have attracted considerable research interest in recent years, prompted by their flexible and intentional pattern of use; but almost all studies have focused on single gestures. Here, we report the first quantitative analysis of sequential gesture use in western gorillas (Gorilla gorilla gorilla), using data from three captive groups and one African study site. We found no evidence that gesture sequences were given for reasons of increased communicative efficiency over single gestures. Longer sequences of repeated gestures did not increase the likelihood of response, and using a sequence was seldom in reaction to communicative failure. Sequential combination of two gestures with similar meanings did not generally increase effectiveness, and sometimes reduced it. Gesture sequences were closely associated with play contexts. Markov transition analysis showed two networks of frequently co-occurring gestures, both consisting of gestures used to regulate play. One network comprised only tactile gestures, the other a mix of silent, audible and tactile gestures; apparently, these clusters resulted from gesture use in play with proximal or distal contact, respectively. No evidence was found for syntactic effects of sequential combination: meanings changed little or not at all. Semantically, many gestures overlapped massively with others in their core information (i.e. message), and gesture messages spanned relatively few functions. We suggest that the underlying semantics of gorilla gestures is highly simplified compared to that of human words. Gesture sequences allow continual adjustment of the tempo and nature of social interactions, rather than generally conveying semantically referential information or syntactic structures.

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Available from: Emilie Genty
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    • "If inter-signal intervals surpassed 1 s, we considered them as belonging to separate sequences. This criterion has been used in gestural research and we thus decided to apply it to make our study comparable with previous work [52], [66], [67]. Strings of two or more sequences by the same individual were defined as a communicative bout (as per [67]). "
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    ABSTRACT: 'Contest hoots' are acoustically complex vocalisations produced by adult and subadult male bonobos (Pan paniscus). These calls are often directed at specific individuals and regularly combined with gestures and other body signals. The aim of our study was to describe the multi-modal use of this call type and to clarify its communicative and social function. To this end, we observed two large groups of bonobos, which generated a sample of 585 communicative interactions initiated by 10 different males. We found that contest hooting, with or without other associated signals, was produced to challenge and provoke a social reaction in the targeted individual, usually agonistic chase. Interestingly, 'contest hoots' were sometimes also used during friendly play. In both contexts, males were highly selective in whom they targeted by preferentially choosing individuals of equal or higher social rank, suggesting that the calls functioned to assert social status. Multi-modal sequences were not more successful in eliciting reactions than contest hoots given alone, but we found a significant difference in the choice of associated gestures between playful and agonistic contexts. During friendly play, contest hoots were significantly more often combined with soft than rough gestures compared to agonistic challenges, while the calls' acoustic structure remained the same. We conclude that contest hoots indicate the signaller's intention to interact socially with important group members, while the gestures provide additional cues concerning the nature of the desired interaction.
    Full-text · Article · Jan 2014 · PLoS ONE
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    • ", 2009 ) , multi - modal communicative combinations ( Leavens et al . , 2010 ; Pollick & de Waal , 2007 ; Tanner , Patterson , & Byrne , 1996 ) , gestural sequences or phrases ( Genty & Byrne , 2010 ; Tanner 2004 ) , and negotiation or co - regulation within communicative interactions , including elaborations ( Cartmill & Byrne , 2007 ; Leavens et al . , 2005 ; 2010 ) . "
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    ABSTRACT: This paper examines the meaningfulness of pointing in great apes. We appeal to Hannah Ginsborg’s conception of primitive normativity, which provides an adequate criterion for establishing whether a response is meaningful, and we attempt to make room for a conception according to which there is no fundamental difference between the responses of human infants and those of other great apes to pointing gestures. This conception is an alternative to Tomasello’s view that pointing gestures and reactions to them reveal a fundamental difference between humans and other apes.
    Full-text · Article · Jul 2013
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    • "These findings are similar to those of Liebal et al. (2004a) and Roberts et al. (2012b) and suggest that gesture sequences occur, at least in part, because of a recipient's lack of response to initial gesture attempts. In contrast, Genty and Byrne (2010) assert that gesture sequences instead function to regulate interactions. We suggest that these possibilities are not mutually exclusive. "
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    ABSTRACT: This study examined the use of sensory modalities relative to a partner's behavior in gesture sequences during captive chimpanzee play at the Chimpanzee and Human Communication Institute. We hypothesized that chimpanzees would use visual gestures toward attentive recipients and auditory/tactile gestures toward inattentive recipients. We also hypothesized that gesture sequences would be more prevalent toward unresponsive rather than responsive recipients. The chimpanzees used significantly more auditory/tactile rather than visual gestures first in sequences with both attentive and inattentive recipients. They rarely used visual gestures toward inattentive recipients. Auditory/tactile gestures were effective with and used with both attentive and inattentive recipients. Recipients responded significantly more to single gestures than to first gestures in sequences. Sequences often indicated that recipients did not respond to initial gestures, whereas effective single gestures made more gestures unnecessary. The chimpanzees thus gestured appropriately relative to a recipient's behavior and modified their interactions according to contextual social cues.
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