We study the evolution of belief systems that suppress productive effort. These include concerns about the envy of others, beliefs in the importance of luck for success, disdain for competitive effort, and traditional beliefs in witchcraft. We show that such demotivating beliefs can evolve when...

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...