It is clear that rituals and sacrifices can bring people together, and it may well be that a group that does such things has an advantage over one that does not. But it is not clear why a religion has to be involved. Why are gods, souls, an afterlife, miracles, divine creation of the universe, and so on brought in?
Paul Bloom
Natural selection shaped the human brain to be drawn toward aspects of nature that enhance our survival and reproduction, like verdant landscapes and docile creatures. There is no payoff to getting the warm fuzzies in the presence of rats, snakes, mosquitoes, cockroaches, herpes simplex and the rabies virus.
Paul Bloom
