Social organization and the evolution of cumulative technology in apes and hominins

Abstract

Culturally supported accumulation (or ratcheting) of technological complexity is widely seen as characterizing hominin technology relative to that of the extant great apes, and thus as representing a threshold in cultural evolution. To explain this divide, we modeled the process of cultural accumulation of technology, which we defined as adding new actions to existing ones to create new functional combinations, based on a model for great ape tool use. The model shows that intraspecific and interspecific variation in the presence of simple and cumulative technology among extant orangutans and chimpanzees is largely due to variation in sociability, and hence opportunities for social learning. The model also suggests that the adoption of extensive allomaternal care (cooperative breeding) in early Pleistocene Homo, which led to an increase in sociability and to teaching, and hence increased efficiency of social learning, was enough to facilitate technological ratcheting. Hence, socioecological changes, rather than advances in cognitive abilities, can account for the cumulative cultural changes seen until the origin of the Acheulean. The consequent increase in the reliance on technology could have served as the pacemaker for increased cognitive abilities. Our results also suggest that a more important watershed in cultural evolution was the rise of donated culture (technology or concepts), in which technology or concepts was transferred to naïve individuals, allowing them to skip many learning steps, and specialization arose, which allowed individuals to learn only a subset of the population's skills.

How institutions shaped the last major evolutionary transition to large-scale human societies

“…However, we note that once it evolved, language had two key consequences for hunter-gatherer social evolution. First, language made teaching more effective, which provided more scope for cumulative cultural evolution and hence the development of new technologies [49,50]. Second, once in place, language enabled individuals to negotiate their rules of social interactions; that is, to start to create institutions for the first time.…”

Why developmental psychology is incomplete without comparative and cross-cultural perspectives

“…In contrast to non-human culture, human culture is: (i) cumulative, i.e. innovations are progressively incorporated into a population's stock of skills and knowledge, generating ever more sophisticated repertoires; (ii) more distinctly variable across communities; and (iii) to a larger extent shaped through social learning [14][15][16].…”

Sociality influences cultural complexity

“…Humans may be unique among species in generating the cumulative cultural evolutionary processes that give rise to complex behavioural skills and technologies [1][2][3][4]. A growing class of theoretical models suggest that the emergence of such complex and 'difficult to learn' cultural traits (tools, techniques and skills), such as many of the technologies used by hunter-gatherers, is heavily influenced by the abilities of learners to access larger social networks of other individuals [5][6][7][8][9][10][11][12][13][14].…”