What can lithics tell us about the evolution of learning and development?

Abstract Prolonged childhood is a remarkable human life history stage that has been linked with uniquely human learning demands and/or developmental costs. Lithics have the potential to tell us about the evolution of childhood, but only if we develop better interpretive models for differentiating the products of juveniles and adults, and for understanding the influence of age on learning aptitudes and costs. Here we discuss an initial experimental study of children learning basic flaking skills. Contrary to the hypothesis of a childhood learning advantage, our child participants performed much more poorly than adults. This was explained at least in part by lower grip strength and mental rotation ability, highlighting the developmental obstacles to child knapping. This implies additional costs to practice and adds no support to the widespread assumption that knapping was predominantly learned in middle childhood. However, there are many reasons to question the generalizability of our specific findings, including idiosyncratic child rearing practices and behavioral norms in our contemporary U.S. sample. More experiments with longer training times and larger samples in more diverse social and cultural contexts are urgently needed. We hope the current report can provide a useful starting point.