in-laws? Resolving the effects of family background and spousal choice for educational attainment, religious practice and political preference

Acknowledgements: We thank Greg Carey for insightful comments on this manuscript. ABSTRACT Objectives: Contemporary scholarly debate emphasizes the importance of spouse selection on population stratification, typically focusing on the traits of spouses themselves. In this study spouses and their parents were analyzed to resolve the effects of direct spousal assortment from family background assortment on three social traits which spouses correlate the highest: education, church attendance and political affiliation. Methods: The data set is comprised of a core of spouse pairs and their parents assessed by self-report and a more extensive set of individuals on whom there are only ratings by relatives for educational attainment, church attendance and political preference. Structural equation Models were fitted to the observed polychoric correlations by diagonal weighted least squares. Results: For education and church attendance, assortment was based primarily on the traits of the spouses themselves, but models including independent assortment for the traits of parents-in-law gave a better fit. For political affiliation, assortment based on social background influenced by the traits of both parents gave a better fit. Conclusions: The findings demonstrate that in humans spousal similarity may reflect processes of selection and stratification that are more complex than commonly supposed in most models for family resemblance and social diversity. 3 Choice of spouse has pervasive implications for the familial transmission of individual and social differences that have attracted the attention of both the life and social sciences. The literature on mate selection in the two approaches shows little sign of mutual recognition and reveals differences of focus and method. However, whether the causes of parent-offspring transmission are genetic or social, or some combination thereof, the tendency to marry alike (" assortative mating ") is expected to have a significant impact on the familial transmission of genetic and environmental risks for disease and on the maintenance and distribution of social behavior because assortative mating increases both the parent-offspring correlation and the population variance for any trait on which assortment is based (Eysenck, 1979; Jencks et al., 1972). For example, relative to expectations under random mating, assortment allows parents, knowingly or unknowingly, to " corner the market " on behaviors and often times advantages, such as educational attainment, thereby increasing diversity in the population, (i.e., widening the education gap) and increasing the familial transmission of socially important values and characteristics (Mare 2000). Similarity between mates is a widely documented feature of human populations. Typically, …