Toward an evolutionary psychology of religiosity.
How can the evolution of religiosity be explained? To answer this question, we attempt to develop an understanding of the psychological domains underlying religious behaviour. We see four evolved domains, the sum and interaction of which constitute religiosity, namely: mysticism, ethics, myths and rituals. Even if the individual content, accents and implementations differ in each specific religion, they nevertheless derive from evolved Darwinian algorithms that are species-specific adaptations of homo sapiens. Mysticism. Intuitive ontologies are the basis for mystical experiences. Usually they serve to classify reality into animate and inanimate objects, animals or plants, for example. For a variety of psychological reasons, supernatural experiences result from a mixture of different ontological categories. Ethics. The basis for ethics lies in the social competency of human beings. Ethics is founded on the concept of social exchange ("social-contract algorithm") with its ideas about reciprocity, fairness, justice, cheater detection, in-group/out-group differentiation, etc. Myths. The basis for myths is the "language instinct". We interpret myths as the verbal expression of the cognitive content of those individual modules that constitute the belief system. Above all, myths document the experience and processing of contingency and thus help social bonding. Rituals. Rituals are based on the handicap principle. By making certain symbols and acts more expensive, they signal commitment for a reliable in-group morale. In conclusion, we argue that human religiosity emerges from a cognitive interaction between these four domains. Religiosity processes contingencies and enhances co-operation through social bonding, norm setting and cheater detection. It fulfils those functions for which the mental modules of its four domains have evolved so that we feel it appears to be justified to attribute to religiosity the evolutionary status of an adaptation.