Special issue: Kin Selection Inclusive fitness theory for the evolution of religion

We describe and evaluate an integrative hypothesis for the origin and evolution of human religious cognition and behaviour, based on maximization of inclusive fitness. By this hypothesis, the concept of God is represented by one's circle of kin and social salience, such that serving God and serving this circle become synonymous. The theory is supported by data from anthropology, evolutionary theory, psychology , neuroscience, psychiatry, endocrinology and genetics. It is largely compatible with, yet can subsume, previous theories of religion that are also based on adaptation and natural selection. There is something sacred about kinship, as most social anthropologists who have studied its operation in the field are prepared to admit (Myers, 1975) W. D. Hamilton's (1964) inclusive fitness theory represents the foundation for studying social evolution, in the same way that Darwin's theory of natural selection forms the basis for understanding evolution itself. Hamilton's theory and its applications have focused in particular on the evolution of cooperation and altruism, behaviours that are challenging to explain because they represent the apparent antitheses of Darwinian competition for increased reproduction. One human phenotype, religious behaviour, stands apart from all others with regard to its dominating emphasis on altruism and prosociality. This set of behaviours has yet to be analysed explicitly and comprehensively in the context of inclusive fitness theory, using the conceptual tools developed in Hamilton's wake for understanding its origins, maintenance and diversification. Like eu-sociality, or cooperative breeding, religion can be considered as a sociobehavioural system that has evolved in the contexts of genetic relatedness, parental manipulation (generalized here as asymmetries in control over phenotypes) and mutualism. In this article we describe and analyse an integrative theory, based on inclusive fitness maximization, for understanding the origin and evolution of religious behaviour and the concepts of God and supernatural agents. The theory is based mainly on works by it draws together evidence from anthropology, psychology, neuroscience, psychiatry, endocrinology and genetics into a unified, testable framework. The theory is novel specifically in its integra-tive, synthetic and reconciliatory nature, and its central emphasis on the roles of genetic relatedness and inclusive fitness in the evolution of religion. We first categorize and describe previous theories regarding the origins, bases and functions of the concept of God and other supernatural agents, and associated religious behaviour. Next, we present the theory, and discuss how it relates to, and can subsume, these earlier ideas without being strongly incompatible …