Differential assortative mating found for academic and demographic variables as a function of time of assessment.

The purpose of this study was to examine changes in spousal similarity that occur as a function of time of assessment and to assess the extent to which assortment is a function of initial versus "realized" similarity. Similarity for academic achievement test scores obtained when adults were in elementary and high-school grades was examined in approximately 170 couples. Similarity for occupational and educational traits achieved in adulthood and during marriage was also assessed. The data suggest small but significant assortative mating for test data obtained while husbands and wives were in elementary school. This is in contrast to the larger and significant spousal correlations observed for high-school test scores. Further adjustment procedures indicated that most of the significant high-school test score correlations remained, even after elementary school academic abilities were controlled for. Moreover, spousal correlations for academic-related variables assessed after marriage, such as occupation and college education, were only slightly higher than high-school test score correlations and showed some shrinkage after controlling for school-aged academic performance. Some minor convergence was found for one of the variables assessed after marriage using a multiple regression procedure advocated by Price and Vandenburg (1980). The discontinuity in assortment found for elementary, high-school, and adult variables is related to the mate selection procedure and how it appears to be based on the phenotype best approximating that of an adult.