Cultural Macroevolution and Adaptation: Relative Evidence for Innovation, Vertical and Horizontal Transmission

University Of California-Davis, Davis CA

Investigators

Abstract

What processes produce similarities and differences among cultures? Cultural traits can be disseminated from parent to daughter populations (vertical transmission), can diffuse across population boundaries (horizontal transmission), and can emerge as independent innovations. The relative importance of each of these different processes of cultural macroevolution lies at the heart of anthropological investigation and to understanding whether cultural and biological evolution are alike. This research investigates these questions by taking advantage of data already available in three anthropological: 1) the Standard Cross-Cultural Sample (SCCS), 2) the East African Data Base (EADb), and 3) the Western North American Indian database (WNAI). First, the researchers will use this information to examine the relationship between the distribution of single traits and the historical and geographical distances between societies. Next, they will investigate different explanations for these patterns by focusing on the co-occurrence of particular sets of traits within societies in the context of historical and geographical distance. Both steps utilize hierarchical modeling, a special form of generalized linear modeling developed for spatial data. This research makes two central theoretical contributions to the broader study of human cultural diversity. First it investigates the appropriateness of the analogy between cultural and biological evolution. Although it is clear that populations are characterized by particular sets of cultural traits, the mechanisms by which these cultural traits are established are not well understood. Second, by distinguishing between trait transmission and social and cultural adaptation, this research will clarify the role of adaptation in contributing to cultural diversity.