Origins and evolution of religion from a Darwinian point of view: synthesis of different theories

The religious phenomenon is a complex one in many respects. In recent years an increasing number of theories on the origin and evolution of religion have been put forward. Each one of these theories rests on a Darwinian framework but there is a lot of disagreement about which bits of the framework account best for the evolution of religion. Is religion primarily a by-product of some adaptation? Is it itself an adaptation, and if it is, does it beneficiate individuals or groups? In this chapter, I review a number of theories that link religion to cooperation and show that these theories, contrary to what is often suggested in the literature, are not mutually exclusive. As I present each theory, I delineate an integrative framework that allows distinguishing the explanandum of each theory. Once this is done, it becomes clear that some theories provide good explanations for the origin of religion but not so good explanations for its maintenance and vice versa. Similarly some explanations are good explanations for the evolution of religious individual level traits but not so good explanations for traits hard to define at the individual level. I suggest that to fully understand the religious phenomenon, integrating in a systematic way the different theories and the data is a more successful approach.