Forward and backward modeling of cultural evolutionary processes

Abstract

Cultural traits can be acquired by social learning from a diverse category of individuals, not limited to biological parents. Cultural change nevertheless constitutes a dynamic evolutionary system, which can be modeled and analyzed using backward or forward approaches derived from the theory of biological evolution. First, we modify genetic coalescent theory to examine the effects of cultural transmission on the age/persistence and popularity of cultural traits such as lithic technologies and consanguineous unions. Then, using a forward approach, we study the emergence of the taboo against sibling incest, which illustrates how an innate tendency may affect the outcome of cultural evolution. Based on these theoretical studies, we discuss the merits and demerits of backward and forward approaches.