Cultural macroevolution: Understanding the rise of large-scale complex societies in human history

During the Holocene the scale and complexity of human societies increased dramatically. Generations of scholars have proposed different theories explaining this evolution, which range from functionalist explanations, focusing on the provision of public goods, to conflict theories, emphasizing the role of class struggle or warfare. To quantitatively test these theories, Peter Turchin develops a general dynamical model, based on the theoretical framework of cultural macroevolution. Using this model and Seshat: Global History Databank he tests 17 potential predictor variables (and >100,000 combinations of these predictors) proxying mechanisms suggested by major theories of sociopolitical complexity. The best-fitting model indicates a strong causal role played by a combination of increasing agricultural productivity and warfare intensity, proxied by invention/adoption of military technologies (most notably, iron weapons and cavalry in the first millennium BCE). Overall, these empirical results support the idea that a major evolutionary force explaining the rise of large-scale complex human societies, organized as states, was Cultural Multi-Level Selection.