When and how do non-human great apes communicate to support cooperation?

Abstract

Several scholars have long suggested that human language and remarkable communicative abilities originate from the need and motivation to cooperate and coordinate actions with others. Yet, little work has focused on when and how great apes communicate during joint action tasks, partly because of the widely held assumption that animal communication is mostly manipulative, but also because non-human great apes' default motivation seems to be competitive rather than cooperative. Here, we review experimental cooperative tasks and show how situational challenges and the degree of asymmetry in terms of knowledge relevant for the joint action task affect the likelihood of communication. We highlight how physical proximity and strength of social bond between the participants affect the occurrence and type of communication. Lastly, we highlight how, from a production point of view, communicators appear capable of calibrating their signalling and controlling their delivery, showing clear evidence of first-order intentionality. On the other hand, recipients appear to struggle in terms of making use of referential information received. We discuss different hypotheses accounting for this asymmetry and provide suggestions concerning how future work could help us unveil to what degree the need for cooperation has shaped our closest living relatives' communicative behaviour. This article is part of the theme issue ‘Revisiting the human ‘interaction engine’: comparative approaches to social action coordination’.

Revisiting the human ‘interaction engine’: comparative approaches to social action coordination

“…Second- or higher-order intentions (i.e. aiming to influence the recipient's knowledge state rather than their behaviour) have been discussed as potentially unique features of human communication ( 58 , 59 ; but see [ 60 ] for potential evidence of second-order intentionality in chimpanzees). It is evident that humans are extraordinary skillful in expressing and recognizing intentions.…”

“…Whether intention recognition also plays a constraining role in great ape cooperation is addressed by Alicia Melis & Federico Rossano [ 58 ]. The authors specifically discuss the cross-modal communicative strategies und underlying degree of intentionality during experimental cooperative stag hunt scenarios—a possible evolutionary niche of the interactional base for language [ 44 ].…”

“…On the one hand, experimental evidence for the ability of producing and especially comprehending communicative signals that would aid the coordination in cooperation paradigms appears to be fairly limited in nonhuman species, such as chimpanzees [ 44 ]. However, recipient affordances such as physical distance and familiarity might affect the coordination process in these artificial scenarios [ 58 ], as they have a major impact on effective communication. Thus, many field researchers who have witnessed spontaneous cooperative interactions in a more natural setting may argue that it is inappropriate, or at best premature, to assume that ‘communicating in order to coordinate does not come naturally and easily to chimpanzees' [ 44 ].…”

“…From our perspective as Guest Editors, five major aspects have become clear from this collection of expertise. First, we learned that social interaction can be scrutinized using an impressive variety of methodological approaches, including detailed video-based transcriptions of action sequences [ 24 , 25 ], classical ethological studies of naturalistic interactions [ 26 , 57 ], experimental paradigms [ 58 ], longitudinal research [ 43 ], and a computational modelling approach [ 64 ]. To our positive surprise, many of these conributions adopted a multimodal approach, bearing witness to long-awaited transitions toward a more holistic study of communicative interactions [ 41 , 83 ].…”

“…What else was needed for language to evolve? Higher orders of intentionality and group-wide prosociality are now by many considered as the key ingredients of the human interaction engine that could have paved the way for the evolution of conventional languages, given that evidence for these features in nonhuman species remains scarce [ 3 , 44 , 58 , 64 ] and because these qualities are partly shared with other, cooperative breeding primates [ 11 ]. Nonetheless, it remains to be seen to what extent this disparity between nonhuman and human animals can be explained by methodological constraints.…”