Building blocks of human sociality: A comparative assessment of joint action in humans and their closest ape relatives

ended

Many social animals collaborate, but only humans supposedly engage in joint action – cooperative interactions that involve normative, mutually obligating joint commitments (JCs). This enabled the evolution of hyper-cooperation observed in human societies, including complex collaborations like governments, and has likely played a pivotal role in human evolution. Given the significance, there has been a long-standing interest in the ontogenetic and evolutionary origins of joint action capacities like JC. The classical approach employed experiments with human children and nonhuman great apes, showing that while humans engage in joint actions, apes’ interactions rely on egoistic motives. However, such tasks are highly anthropocentric, involving engagement with human confederates in human-centric tasks. Conversely, drawing on a more ecologically valid approach, my research demonstrates that when apes interact with conspecifics naturally, they appear to exhibit specific joint action capacities like JC. Yet firm conclusions cannot be drawn unless the following empirical issues are solved: i) behaviours do not permit insights into internal mechanisms, ii) comparative joint action research is still in its infancy, lacking a holistic picture of affective and behavioural processes supporting coordination, and iii) previous ape studies are deficient of critical experimental controls. Building on and expanding my unique expertise in this domain, this project overcomes these challenges by pioneering a comparative investigation of spontaneous joint action coordination in human children and bonobos. Using cutting-edge tracking and thermal imaging techniques, as well as timely controls, the project explores pivotal joint action signatures like communicative repair, bodily synchrony, and JC-related emotions. This offers a powerful assessment of the hypothesis that humans and apes share basic joint action capacities, highlighting the evolutionary building blocks of human sociality.