Social attitudes, political attitudes and religiousness are highly inter-correlated. Furthermore, each is substantially influenced by genetic factors. Koenig and Bouchard (2006) hypothesized that these three areas (which they termed the Traditional Moral Values Triad) each derive from an underlying latent trait concerning the tendency to obey traditional authorities. We tested this hypothesis with data from a sample of twins raised in different homes. We assessed social attitudes with Altemeyer's (1988) Right-Wing Authoritarianism scale, political attitudes with Wilson and Patterson's (1968) Conservatism scale, and religiousness with Wiggins' (1966) Religious Fundamentalism scale. The best-fitting model identified the three TMVT domains as different manifestations of a single latent and significantly heritable factor. Further, the genetic and environmental bases for this factor overlapped heavily with those for the Multidimensional Personality Questionnaire Traditionalism scale, supporting the conception of traditionalism as the latent factor represented by the three scales in contemporary Western societies.