Phenotypic assortative mating vs. social homogamy among Japanese and Chinese parents in the Hawaii Family Study of Cognition

Among the subjects of Japanese and Chinese ancestries in the parent generation in the Hawaii Family Study of Cognition were 47 pairs of siblings. Since data were available on the spouses of these siblings, this allowed for tests of whether spouse correlations of educational and occupational attainment and cognitive abilities were due to active phenotypic assortment and/or shared social background (social homogamy). Comparisons of sibling correlations, spouse correlations, and correlations between the spouse of one sibling and the spouse of the other sibling, as well as the results of model-fitting analyses, suggest that spouse correlations for education are determined by both phenotypic assortment and social homogamy, spouse correlations for occupational attainment by phenotypic assortment, and spouse correlations for verbal ability mostly by social homogamy.