Sources of regional variation in social capital in the United States: Frontiers and pathogens

The present study sought to explore the contribution of a number of factors to regional variation among U.S. states in social capital with a focus on the impact of frontier settlement and levels of pathogen prevalence. As predicted, date of statehood was positively correlated with state-level scores on Putnam's social capital index, as well as generalized trust, number of group memberships, and hours spent volunteering, and parasite stress was negatively correlated with these four variables. Controlling for parasite stress eliminated or reduced the relationship between date of statehood and each of these variables, suggesting that differences in parasite stress may underlie differences between frontier and nonfrontier regions of the U.S. in terms of social capital. The relationship between parasite stress and social capital was quite robust, with parasite stress remaining a significant predictor when controlling for a number of other factors.