Cooperation and teaching in the context of cumulative culture

Abstract

Cumulative culture enables humans to shape their niche and to live in extreme environments. To understand the factors enabling cumulative culture, we need to understand which cognitive abilities support it, how they develop through life, and how they evolved. Different hypotheses have been put forward as to which cognitive abilities – namely innovation, imitation, teaching, and cooperation – are most essential for the emergence of cumulative culture. In this dissertation I review evidence for each these abilities and discuss three studies that I conducted to investigate the latter two concepts – teaching, and cooperation. The first study used a tool-exchange paradigm to compare the altruistic and cooperative abilities of our two closest living relatives, chimpanzees and bonobos. Bonobos were more likely to transfer tools to a partner than chimpanzees in both an altruistic and cooperative context. The second study investigated the ability of chimpanzees to teach new skills to an ignorant conspecific. I found no evidence that chimpanzees were able to teach, even with incentives to do so. This is very different to the behaviour of children in the final study. In this study I investigated whether children, between the ages four to seven years, would teach an ignorant partner and whether the strategies employed depended on their age or the potential benefits of successful teaching. Children of all age groups taught their partner and employed a variety of teaching strategies. Children used more iconic gestures and explanations (i.e. information the partner could directly enact) when they would benefit from having a competent partner rather than a partner whose actions did not result in benefits. I discuss the results of these studies in terms of their implication for the debate on the evolution of cumulative culture and will argue that flexible teaching and enhanced altruistic motivation enabled modern humans to outcompete most species with which we share the planet.