Do Genetic Factors Influence Religious Life? Findings from a Behavior Genetic Analysis of Twin Siblings

Social scientific research assumes that religious involvement is primarily, if not exclusively, the product of social-environmental influences. There is growing evidence, however, that genetic or other biological factors also play a role. Analyzing twin sibling data from the National Survey of Midlife Development in the United States (MIDUS), this study addresses this issue by showing that individual-level variation on four different aspects of religious life-organizational involvement, personal religiosity and spirituality, conservative ideologies, and transformations and commitments-is indeed the product of both genetic and environmental influences. Specifically, genetic factors explain 19-65 percent of the variation, while environmental influences account for the remaining 35-81 percent depending upon the aspect of religion under investigation. Research of this type enhances contemporary social science by providing a new perspective that nicely supplements existing ones, but it also highlights potential implications, including explanatory power deficiencies and potentially bias.