Complex patterns of signalling to convey different social goals of sex in bonobos, Pan paniscus
2015, Genty, Emilie, Neumann, Christof, Zuberbühler, Klaus
Sexual behaviour in bonobos (Pan paniscus) functions beyond mere reproduction to mediate social interactions and relationships. In this study, we assessed the signalling behaviour in relation to four social goals of sex in this species: appeasement after conflict, tension reduction, social bonding and reproduction. Overall, sexual behaviour was strongly decoupled from its ancestral reproductive function with habitual use in the social domain, which was accompanied by a corresponding complexity in communication behaviour. We found that signalling behaviour varied systematically depending on the initiator's goals and gender. Although all gestures and vocalisations were part of the species-typical communication repertoire, they were often combined and produced flexibly. Generally, gestures and multi-modal combinations were more flexibly used to communicate a goal than vocalisations. There was no clear relation between signalling behaviour and success of sexual initiations, suggesting that communication was primarily used to indicate the signaller's intention, and not to influence a recipient's willingness to interact sexually. We discuss these findings in light of the larger question of what may have caused, in humans, the evolutionary transition from primate-like communication to language.
Spatial Reference in a Bonobo Gesture
2014, Genty, Emilie, Zuberbühler, Klaus
Great apes frequently produce gestures during social interactions to communicate in flexible, goal-directed ways [1-3], a feature with considerable relevance for the ongoing debate over the evolutionary origins of human language [1, 4]. But despite this shared feature with language, there has been a lack of evidence for semantic content in ape gestures. According to one authoritative view, ape gestures thus do not have any specific referential, iconic, or deictic content, a fundamental difference versus human gestures and spoken language [1, 5] that suggests these features have a more recent origin in human evolution, perhaps caused by a fundamental transition from ape-like individual intentionality to human-like shared intentionality . Here, we revisit this human uniqueness claim with a study of a previously undescribed human-like beckoning gesture in bonobos that has potentially both deictic and iconic character. We analyzed beckoning in two groups of bonobos, kept under near natural environmental and social conditions at the Lola Ya Bonobo sanctuary near Kinshasa, Democratic Republic of Congo, in terms of its linguistic content and underlying communicative intention.
Multi-Modal Use of a Socially Directed Call in Bonobos
2014, Genty, Emilie, Clay, Zanna, Hobaiter, Catherine, Zuberbühler, Klaus
'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.
How apes get into and out of joint actions: Shared intentionality as an interactional achievement
2020, Genty, Emilie, Heesen, Raphaela, Guéry, Jean-Pascal, Rossano, Federico, Zuberbühler, Klaus, Bangerter, Adrian
Compared to other animals, humans appear to have a special motivation to share experiences and mental states with others (Clark, 2006; Grice, 1975), which enables them to enter a condition of ‘we’ or shared intentionality (Tomasello & Carpenter, 2005). Shared intentionality has been suggested to be an evolutionary response to unique problems faced in complex joint action coordination (Levinson, 2006; Tomasello, Carpenter, Call, Behne, & Moll, 2005) and to be unique to humans (Tomasello, 2014). The theoretical and empirical bases for this claim, however, present several issues and inconsistencies. Here, we suggest that shared intentionality can be approached as an interactional achievement, and that by studying how our closest relatives, the great apes, coordinate joint action with conspecifics, we might demonstrate some correlate abilities of shared intentionality, such as the appreciation of joint commitment. We provide seven examples from bonobo joint activities to illustrate our framework.
Bonobos modify communication signals according to recipient familiarity
2015, Genty, Emilie, Neumann, Christof, Zuberbühler, Klaus
Human and nonhuman primate communication differs in various ways. In particular, humans base communicative efforts on mutual knowledge and conventions shared between interlocutors. In this study, we experimentally tested whether bonobos (Pan paniscus), a close relative to humans, are able to take into account the familiarity, i.e. the shared interaction history, when communicating with a human partner. In five experimental conditions we found that subjects took the recipients' attentional state and their own communicative effectiveness into account by adjusting signal production accordingly. More importantly, in case of communicative failure, subjects repeated previously successful signals more often with a familiar than unfamiliar recipient, with whom they had no previous interactions, and elaborated by switching to new signals more with the unfamiliar than the familiar one, similar to what has previously been found in two year-old children. We discuss these findings in relation to the human capacity to establish common ground between interlocutors, a crucial aspect of human cooperative communication.