This article proposes that integrative differences mediate the relationship between demographic size and political complexity. Hypotheses are supported by a review of previous literature.

How did moralizing religions rise, and what have they caused? The authors test the Big Gods theory, which suggests moralizing religions as a predictor of large-scale complex societies. In addition, they propose their hypothesis, which indicates that warfare, animal husbandry, and agricultural productivity have a role in producing moralizing religions. The results show no significant support for the Big Gods hypothesis. However, they support intergroup warfare, particularly military technologies and cavalry, as an important predictor of social complexity and moralizing religions. In addition, pastoralism has a moderate effect as a predictor for the rise of moralizing religions.

Using the compiled database "Seshat: Global History Databank," researchers sampled 30 societies from 10 distinct regions of the world, testing 51 variables that were condensed into 9 "complex characteristic" variables. Researchers tested for correlates in how societies evolve structurally. Utilizing principal component analysis it was demonstrated that the complex characteristic variables were strongly associated, leading to theorization of structural and social evolution predictability.