While it is widely accepted that there are a multitude of variables that contribute to a society’s level of democracy, the authors of this study argue that the prevalence of consanguinity is one that is often overlooked. Using a sample of 70 nations, they tested the relationship between consanguinity (defined as marriage and subsequent mating between second cousins or closer relatives) and level of democracy (defined by both the Polity IV scale and the EIU Index) and found a significant negative relationship. Similarly, when controlled for a host of different variables in multiple regression analysis, the significant relationship between consanguinity and level of democracy held true.

This paper adds to a body of research which analyzes the persistence of institutional features in societies over time by testing for association between local democracy (succession by consensus among preindustrial groups) and various measures of democracy in contemporary societies. The researchers conclude that beliefs and values which perceive democracy as a viable political structure may be an important mediating mechanism in producing and maintaining democratic instututions over time.

The authors propose that societies with a tradition of rice farming are less likely to develop a democracy than societies with a tradition of wheat farming. They base their predictions on the theory that wheat farming, as opposed to rice farming, does not require extensive community collaboration and promotes individualism, which then in turn promotes democracy. Their findings were robustly consistent with their predictions. The authors used multiple controls in their analyses, including religion, economic development, geography, and local democratic practices.