Article ID: 2020-B006
This study examined whether religiosity moderates the genetic and environmental etiology of the Big Five personality traits (Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness). Data from a nationwide sample of 549 twin pairs collected through the MacArthur Foundation National Survey of Midlife Development in the United States were analyzed. Analyses of a gene–environment interaction model revealed that religiosity moderated the magnitude of genetic and environmental influences on Agreeableness and Conscientiousness; for those who were religious, environmental influences on Agreeableness and genetic influences on Conscientiousness were greater. Religiosity exhibited weak main effects on both traits, with higher religiosity contributing to higher levels of both traits. These results suggested that religiosity serves as a psychological immune system that restricts individuals’ levels of Agreeableness and Conscientiousness within a religiously appropriate range, insulating them from internal and external forces. Implications for personality theory and molecular genetic research on personality and psychopathology are discussed.