Signaling, Solidarity, and the Sacred: The Evolution of Religious Behavior

Many challenges confront evolutionary scholars of religion. The origins and adaptive value of religion and the conditions that selected for its evolution are difficult to discern. Patterns of religious behavior, like other areas of human social behavior, have undergone significant change over our evolutionary history. Evans-Pritchard1 argued that dramatic historical changes in religious behavior render it impossible to generalize across categories of religions such as tribal, chiefdom, and contemporary world religions. Evolutionary theories of religion, however, necessarily assume that the relevant behaviors can be generalized across time and space. Moreover, the multiple roles and complex functions of religion render it difficult to capture within a single theoretical approach. Indeed, examining the origins of religion, the development of religious institutions, the ecological determinants of religious behavior, and whether religion is currently adaptive constitute separate areas of inquiry requiring different methodological tools. Even when analyses are restricted to a specific time and place, there is an extensive range of phenomena that fall under the rubric of religion, including myth, ritual, taboo, symbolism, morality, altered states of consciousness, and belief in noncorporeal beings. Concomitantly, there is enormous crosscultural variability within any one of these phenomena. Religious behaviors often entail significant proximate costs, such as time, energetic, and material costs, as well as physical and psychological pain, that appear to be greater than any derived benefits. Consequently, religious behavior poses a genuine challenge for those who employ optimization, rational choice, or other egoisticbased models to explain human behavioral variation. Researchers have sought to unravel this dilemma by positing somatic, reproductive, and psychological benefits conferred by religious behaviors on their practitioners that could outweigh these costs. Realized benefits include improved health, survivorship, economic opportunities, sense of community, psychological well-being, assistance during crises, mating opportunities, and fertility (see Reynolds and Tanner27 for a review). Various scholars have independently concluded that religious communities are able to offer many of these benefits because religions solve significant communication problems inherent in human life.28–31 Although our understanding of how religion solves such problems is still incomplete, recent theoretical and empirical findings offer intriguing clues to religion’s evolution and efficacy.