Socioecology shapes child and adolescent time allocation in twelve hunter-gatherer and mixed-subsistence forager societies

Abstract

A key issue distinguishing prominent evolutionary models of human life history is whether prolonged childhood evolved to facilitate learning in a skill- and strength-intensive foraging niche requiring high levels of cooperation. Considering the diversity of environments humans inhabit, children’s activities should also reflect local social and ecological opportunities and constraints. To better understand our species’ developmental plasticity, the present paper compiled a time allocation dataset for children and adolescents from twelve hunter-gatherer and mixed-subsistence forager societies (n = 690; 3–18 years; 52% girls). We investigated how environmental factors, local ecological risk, and men and women’s relative energetic contributions were associated with cross-cultural variation in child and adolescent time allocation to childcare, food production, domestic work, and play. Annual precipitation, annual mean temperature, and net primary productivity were not strongly associated with child and adolescent activity budgets. Increased risk of encounters with dangerous animals and dehydration negatively predicted time allocation to childcare and domestic work, but not food production. Gender differences in child and adolescent activity budgets were stronger in societies where men made greater direct contributions to food production than women. We interpret these findings as suggesting that children and their caregivers adjust their activities to facilitate the early acquisition of knowledge which helps children safely cooperate with adults in a range of social and ecological environments. These findings compel us to consider how childhood may have also evolved to facilitate flexible participation in productive activities in early life.

Foraging complexity and the evolution of childhood

“…Our results suggest that children may specialize in fruit and fish/shellfish collection early on, even as they continue to gain skill in more complex tasks as they grow. Furthermore, social learning and social foraging can also scaffold children’s participation in food production, even if they have not yet acquired all underlying skills ( 41 ). For example, children can help identify tuber vines before they are strong enough to collect them themselves.…”

Agent-based models of the cultural evolution of occupational gender roles

“…In subsistence societies, psychological and cognitive sex differences should reflect, more or less directly, the divergence of male and female roles within that society. For instance, behavioural segregation of children among foragers is related to the subsistence activities of their parents [26]. Similarly, while Vashro et al found sex differences in spatial cognition among the Twe and Himba, where adult social roles include very divergent geographical mobility [27], Trumble et al found no sex difference in spatial cognition among the Tsimane, where men and women tend to have similar geographical travel patterns [28].…”

Sedentarization and maternal childcare networks: role of risk, gender and demography

“…Thus, increasing gender segregation occurs, with downstream effects for children's work. For instance, in a cross-cultural analysis Lew-Levy et al [111] found that sex differences in children's work increased in societies with stricter sexual divisions of labour. Cross-culturally, girls tend to prefer more face-to-face time with adults, particularly, women, than boys (who more often assort with male peers) [96,102,112].…”