Cultural Evolution

What gave rise to the mosaic of cultural expressions across the globe? Why are some societies more culturally diverse than others? This study develops a unified theory of cultural evolution, characterizing the forces that have governed this process over the course of human existence. The research advances the hypothesis that population movements and socioeconomic transformations generated a mismatch between inherited cultural traits and prevailing ecological and societal conditions, setting in motion an evolutionary process governed by adaptation-based vertical transmission, horizontal diffusion, and fitness-based evolutionary selection. The theory generates novel testable predictions concerning the origins of the global cultural mosaic and the cross-societal variation in cultural diversity. First, greater ecological distance between ancestral environments generated greater cultural distance across societies. Second, prehistoric differences in ancestral diversity contributed to divergent adaptive capacity and greater cultural distance. Third, societies descended from more diverse prehistoric populations exhibit greater cultural diversity despite convergence induced by adaptation to a common environment and societal norms. Drawing on measures of cultural distance and diversity derived from folkloric and musical traditions among ethnic groups, visual representations of common concepts, and the dispersion of norms, values, and attitudes, the empirical analysis lends credence to the predictions of the theory.