Couple Similarity on Personality, Moral Identity and Spirituality Predict Life Satisfaction of Spouses and Their Offspring

This study examined the effects of couple similarity on spouses’ and children’s life satisfaction using a large representative sample of 1761 participants (587 married couples and their children). Drawing on the stimulus–value–role theory demonstrating couple similarities in different domains, similarities on personality and value (moral identity and spirituality) was investigated. Based on evolutionary perspectives and the vulnerability–stress–adaptation model of marriage, we hypothesized that couple similarities in these domains are associated with spouses’ life satisfaction. We further proposed that couple similarities may be beneficial for offspring’s well-being. The Actor–Partner Interdependence Model was used to test the independent contribution of couple similarity. The PROCESS macro Model 4 was used to test the direct and indirect effects of similarity on children’s life satisfaction. The results showed (1) Similarity on agreeableness, openness, moral identity, and spirituality contributed to spouses’ life satisfaction after controlling for actor effects, partner effects, and Normative-Desirability Confound; (2) Similarity on moral identity had indirect effect on children’s life satisfaction through fathers’ life satisfaction, and similarity on spirituality had not only a direct effect on children’s life satisfaction but also an indirect effect through fathers’ life satisfaction. These findings are consistent with evolutionary perspectives that positive assortment can enhance reproductive fitness through improved marital functioning. This study also provides support for the vulnerability–stress–adaptation model of marriage, suggesting that couple similarity may serve as enduring strengths that promote adaptive processes in marital relationships.