Tacit Cooperation Influenced Intimate Relationship Satisfaction: The Moderating Roles of Coordination Game Type and Developmental Stage of Relationship

Intimate relationship satisfaction serves as a core pillar of individual psychological well-being and marital stability, yet the role of implicit interpersonal dynamics, particularly tacit cooperation, remains underexplored alongside its boundary conditions. To fill this research gap, the present research adopted a stepwise empirical design to examine whether and how tacit cooperation shapes romantic relationship satisfaction across distinct interaction structures and relational developmental stages, while further establishing the causal direction of this association through experimental evidence. Study 1 ( N = 80 heterosexual couples) adopted a symmetric coordination game with zero conflict of interest and showed that the developmental stage of relationship moderated the association between tacit cooperation and satisfaction: Tacit cooperation positively predicted relationship satisfaction only in Knapp’s coming-together phase, with no significant effect detected in the coming-apart phase. Study 2 ( N = 91 heterosexual couples) employed an asymmetric coordination game involving partial conflict of interest, revealing that tacit cooperation positively predicted relationship satisfaction across both developmental stages; additionally, social status served as a positive predictor of couples’ tacit cooperation. Study 3 ( N = 54 heterosexual couples) established causality via priming perceived tacit cooperation and revealed that priming low tacit cooperation reduced relationship satisfaction, while priming high tacit cooperation yielded no boosting effect. Collectively, these findings demonstrate that tacit cooperation is a robust predictor of intimate relationship quality, especially in asymmetric conflict-laden scenarios. This research clarifies the core nature of implicit positive interactions in romantic relationships, providing targeted theoretical and practical implications for promoting and sustaining high-quality intimate bonds.