Cultural inheritance is driving a major transition in human evolution

Abstract

An evolutionary transition in individuality (ETI) is the emergence of a new level of biological complexity, such as multicellular life or eusocial insects. There is disagreement on the degree to which the human species is undergoing such a transition. Here, we advance a theory of long-term human evolution in which a transition in individuality is driven by an underlying transition in inheritance from DNA to cultural signals. We argue that such a transition could be driven by three features of human culture. First, human cultural inheritance provides greater capacity for rapid adaptation than genetic inheritance. Second, culture constitutes a mechanism of extreme heritable behavioral plasticity. These two features are sufficient to drive an evolutionary transition in inheritance. Third, cultural evolution generates and favors group-level adaptations. Therefore, we argue that an inheritance transition from genes to culture will cause a simultaneous transition in individuality from individual to group. We present a conceptual model of a coupled evolutionary transition in inheritance and individuality and review available evidence. The coupled transition hypothesis has major implications for causation in human evolution and the social sciences. We suggest a set of testable predictions and outline a research agenda on the culture-driven transition in human evolution.