Time-consuming and costly religious rituals pose a puzzle for economists committed to rational choice theories of human behavior. We propose that religious rituals promote in-group trust and cooperation that help to overcome collective-action problems. We test this hypothesis on communal...

We design a decision-making scenario experiment on Facebook to measure subjects’ altruism and trust toward attendees of a religious service, a fitness class and a local music performance. Secular and religious subjects alike display significantly more altruism and trust toward the synagogue...