Several studies have shown that dictator-game giving declines substantially if the dictator can exploit situational "excuses" for not being generous. In this experimental study we investigate if this result extends to more natural social interactions involving reciprocal behavior. We provide the...

NGOs and other non-profit organizations attract workers who strongly identify themselves with their missions. We study whether these "good guys" are more trustworthy and how such pronounced group identities affect trust and trustworthiness within the groups and toward out-groups. We find that...