To explain the extremely long-term persistence (more than 500 years) of positive historical experiences of cooperation (Putnam 1993), we model the intergenerational transmission of priors about the trustworthiness of others. We show that this transmission tends to be biased toward excessively...

In the past decade, nearly 20 studies have found a strong, persistent pattern in surveys and behavioral experiments from over 40 countries: individual exposure to war violence tends to increase social cooperation at the local level, including community participation and prosocial behavior. Thus...