Is Greater Partner Similarity in Educational Attainment Reflecting Greater Genetic Resemblance? A Molecular Genetic Study

Assortative mating can lead to a greater pooling of advantages and disadvantages in families and enforce boundaries between social groups. To the degree that characteristics for mate selection have a genetic component, phenotypic assortative mating on these characteristics might also affect genetic similarity between partners. Greater genetic similarity between partners can lead to greater genetic within-family resemblance and greater between-family differences in an offspring generation. While higher degrees of assortative mating in a population may result in life chances being more unequally distributed in an offspring’s generation, this could lead to inequalities in society may be even harder to overcome. Utilizing molecular genetic information on 1,374 parental pairs from the German Twin Family Panel (TwinLife), we investigate (1) the extent to which similarity in partners, with regard to years of education and occupational status, corresponds to genetic partner similarity, and (2) to what extent the genetic similarity varies across occupational status groups. Our results showed about 17% of the phenotypic similarities in partners’ educational attainment and occupational status was explained by the polygenic score correlations between partners. The degree of genetic partner similarity did not vary across low, middle and high occupational status groups, with one exception for fathers in the high occupational status group. Our results thus support the idea that partner similarity in educational attainment and occupational status is associated with genetic resemblance, while the observed patterns for occupational groups might have worked into the direction of higher social mobility.