California Center for Population Research

How much husbands and wives resemble each other on socioeconomic status and other social traits has long been a concern for demographers and students of social stratification. For demography, assortative mating patterns govern the social makeup of marriages and families. For stratification, spousal resemblance is an indicator of openness or closure of the social order. When people tend to marry within their own social stratum, populations and societies are more closed when they commonly marry members of other socioeconomic groups. But more that just an indicator of family structure and social differentiation, assortative mating is also a part of the dynamic process by which populations and social hierarchies reproduce. The formation and persistence of marriages affects levels and patterns of fertility and thus population growth rates and age structures. The kinds of marriages that form between persons of varying social characteristics determine the "family backgrounds" for their offspring and thus affect the social characteristics of the next generation. At the family and individual levels, mothers and fathers affect the eventual social standing of their children. At the population and cohort levels, the joint distribution of parents' characteristics affect the level and distribution of offsprings' characteristics. Assortative mating, in short, is a key step in the reproduction of populations and social hierarchies from generation to generation and from one period to the next.