Cooperation and Commune Longevity: A Test of the Costly Signaling Theory of Religion

The costly signaling theory of religion posits that religious rituals and taboos can promote intragroup cooperation, which is argued to be the primary adaptive benefit of religion. To test this theory, the authors collected historical data on the constraints and ritual requirements that eighty-three 19th-century U.S. communes imposed on their members. All communes must solve the collective action problem of cooperative labor to survive; thus, they are an ideal population to assess the impact of ritual and taboo on intragroup cooperation. The authors evaluated whether communes that imposed costlier requirements survived longer than less demanding communes and whether costly requirements and religiosity interact to promote cooperation. The results support aspects of the costly signaling theory of religion and reveal new avenues for its development. The authors discuss some of the shortcomings of the theory and explore ways to expand the theory that incorporate additional features of ritual and religious belief.