Trends and Variation in Assortative Mating: Causes and Consequences

Assortative mating fundamentally shapes the characteristics of families and the reproduction of populations. It organizes people into families and determines the characteristics of parents. In this article, I review the literature on the causes and consequences of trends and variation in assortative mating. Explanations for why assortative mating varies have been dominated by modernization theory, but perspectives emphasizing economic inequality and gender inequality have gained momentum in recent years. Underexplored is how changes in the structure of search have affected mate selection. The idea that assortative mating affects inequality and population composition is one of the primary motivations for its study but, until recently, has rarely been tested empirically. I review the literature on the consequences of assortative mating for (a) inequality within generations, (b) inequality between generations, (c) long-run population change, and (d) relationship quality and dissolution. I conclude with suggestions for future research.