Here's the opening of an interesting new paper that will be presented at this year's Human Behavior and Evolution Society meeting at Cal State Fullerton from May 27-31. "Consanguinity" means cousin marriage (typically, second cousins or closer relations):
It has been speculated that high levels of consanguinity within countries (mating between second cousins or closer, F<0.0156), prevents democratic nation building. High degrees of consanguinity within ethnic kinship groupings (traditional tribal groups and clans) are thought to generate mistrust between those groups through the reinforcement of endogamous social and biological arrangements, with non-democratic regimes emerging as a consequence of individuals turning to reliable kinship groupings for support rather than the market or the state (Kurtz, 2002; Sailer, 2004).
Consanguinity as a major predictor of levels of democratization in a study of 55 countries.This study reports the existence of a significant and robust correlation at the national data scale between consanguinity (as measured by the coefficient of inbreeding), and levels of democratization (as measured by the Economist Intelligence Unit’s Democracy Index) for a sample of 55 countries (r=-.77, P<.05). Comparative correlative analysis found that democracy exhibits a higher magnitude correlation with consanguinity than with measures of nine other factors believed to influence levels of democracy (economic freedom; education; GDP per capita; history of foreign occupation in last 100 years; human development; inequality; IQ; media age; and percentage exports in non-renewable resources). Multiple regression analysis further revealed that consanguinity was the strongest predictor of differences in levels of democracy, although three factors (history of foreign occupation in last 100 years; inequality; and percentage exports in non-renewable resources) also produced statistically significant β coefficients. These results are interpreted in light of the theory that democracy only seems to be an optimal political system for countries in which consanguinity has not allowed for the extensive perpetuation of genetically closed kinship groupings (clans or tribes), as these will tend to maximize both their collective utility and inclusive fitness through securing resources at the expense of other kinship groupings.
Michael A. Woodley
Institution: School of Biological Sciences, Royal Holloway, University of London.