Dynamic Assortative Mating on Personality and Affective States in Romantic Couples

Assortative mating refers to the phenomenon in which romantic partners share similarities with one another based on demographic, physical, and psychological characteristics. Primary and meta-analytic research has demonstrated weak patterns of assortment based on one-time measures of Big Five personality traits. The current research expanded the investigation to include dynamic fluctuations in personality and affective states. Pilot data were collected on 138 monogamous romantic couples who have been together for at least 12 months. Participants provided both baseline trait data and dynamic state data five times a day across a seven-day period. The current study focused on two primary research questions: (1) the evidence for assortative mating and (2) the benefits of assortative mating for measured relationship satisfaction. We found evidence for assortative mating based on both baseline traits and dynamic states for the personality and affective variables. However, there was more evidence for perceived similarities than actual similarities at baseline, and there was much more evidence for dynamic similarities on states than baseline similarities on traits. We also found a complementarity effect such that partners were negatively correlated with one another on Volatility. On the other hand, there was little evidence to support the benefits of assortative mating for relationship satisfaction, either using baseline traits or state fluctuations. Nonetheless, in accordance with positive resonance theory, we found that co-fluctuations on positive affect was associated with better relationship satisfaction for both partners. This research highlighted the importance of including finer grain constructs and multiple measurement perspectives of psychological characteristics in the dyadic context.