Supplementary materials to: Differing levels of gratitude between romantic partners: Concurrent and longitudinal links with satisfaction and commitment in six dyadic datasets

Gratitude promotes high quality relationships, but what happens when partners differ in their levels of gratitude? We examined the dyadic nature of gratitude in relationships using six longitudinal datasets (562 couples). Approaching the dyadic effect from the perspective of a “weak-link” hypothesis, we tested if the link between one partner’s gratitude and relationship quality is reduced if the other partner is low in gratitude. Our results overall did not support this hypothesis as they indicated that grateful individuals were more satisfied and committed at baseline, and more grateful and committed over time, regardless of their partner’s level of gratitude. As an alternative way to conceptualize the dyadic effect of gratitude, we explored a potential similarity effect using Dyadic Response Surface Analysis. Our results revealed no unique effect of having two partners reciprocating the same levels of gratitude above and beyond the effect of each partner’s gratitude.