The domains in which people most strongly chose mates who were similar to themselves were politics, religion, intelligence and substance use

A comprehensive meta-analysis of human assortative mating in 22 complex traits. Tanya B Horwitz, Matthew C Keller. bioRxiv, Mar 20 2022. https://doi.org/10.1101/2022.03.19.484997

Abstract: Assortative mating (AM) occurs when the correlation for a trait between mates is larger than would be expected by chance. AM can increase the genetic and environmental variation of traits, can increase the prevalence of disorders in a population, and can bias estimates in genetically informed designs. In this study, we conducted the largest set of meta-analyses on human AM published to date. Across 22 traits, meta-analyzed correlations ranged from r = .08 to r = .58, with social attitude, substance use, and cognitive traits showing the highest correlations and personality, disorder, and biometrical traits generally yielding smaller but still positive and nominally significant (p < .05) correlations. We observed high between-study heterogeneity for most traits, which could have been the result of phenotypic measurement differences between samples and/or differences in the degree of AM across time or cultures.