foraging and the importance of knowledge in Pemba, Tanzania: implications for childhood evolution

Childhood is a period of life unique to humans. Childhood may have evolved through the need to acquire knowledge and subsistence skills. In an effort to understand the functional significance of childhood, previous research examined increases with age in returns to foraging across food resources. Such increases could be due to changes in knowledge, or other factors such as body size or strength. Here we attempt to unpack these age-related changes. First we estimate age-specific foraging returns for two resources. We then develop non-linear structural equation models to evaluate the relative importance of ecological knowledge, grip strength, and height in a population of part-time children foragers on Pemba island, Tanzania. We use anthropometric measures, estimates of ecological knowledge, and behavioral observations for 63 individuals across 370 foraging trips. We find slower increases in foraging returns with age for trap hunting than for shellfish collection. We do not detect any eff...