Growing together or growing apart? The dyadic effects of self‐expansion from two sources on personal and relational well‐being among Chinese Newlywed Couples

This study tested the dyadic effects of self-expansion from partners (relational self-expansion, RSE) and others (personal self-expansion, PSE) on their relational well-being (RWB, e.g., marital satisfaction) and personal well-being (PWB, e.g., life satisfaction) one year later among 289 Chinese newlyweds. Self-expansion and well-being were measured using self-reported scales. Actor-partner interdependence Models (APIM) and dyadic response surface analyses (DRSA) were adopted to examine the dyadic effects of RSE and PSE on RWB and PWB. The results of the APIM supported the positive actor effect of RSE on RWB and PWB one year later for both husbands and wives, as well as a positive partner effect of wives' RSE on husbands' RWB. Furthermore, the results from DRSA supported that both partners were satisfied with their relationships and personal lives when they scored high on RSE or increased in it over time. For PSE, both partners' increase in it was associated with their high PWB, and congruent changes between partners were associated with higher levels of later RWB for both partners.