My goal was to examine potential moderators that affect emotional coordination between romantic partners. I conducted three separate empirical studies that are conceptually related. I used data collected in conjunction with Dr. Emily Butler (all 3 papers), and Dr. Shanmukh Kamble of Karnatak University, India (paper 3). Using models of two forms of emotional coordination in partners - emotion transmission and synchrony - I examined the moderating effects of attachment, cooperation and marriage type on emotional coordination between partners. The purpose of first paper was to examine the role that individual factors, specifically differences in attachment avoidance and anxiety, have on the transmission of emotions between partners. Interestingly, results were counter to hypotheses based on attachment differences in emotion regulation, which suggests the limitations of taking an individual perspective within dyadic contexts. The second paper examined how cooperation impacts emotional coordination between partners. I found that cooperation produces different emotional coordination patterns for men and women. Specifically, when both partners were at high levels of cooperation, men showed an in-phase emotional coordination pattern (changes in unison), whereas women showed an anti-phase emotional coordination (changes in opposite directions). Therefore, while both partners were engaging in similar behaviors their emotional experience was different. In the third paper, I moved to a more global analysis of factors that moderate emotional synchrony between partners. Specifically, I examined how different marriage-types in American and Indian cultures (love versus arranged marriages) impact emotional synchrony between partners. I expected that Indian-love marriages would show similar synchronization patterns to American marriages, and that both would show more synchrony in comparison with Indian-arranged marriages. Unexpectedly, Indian-love and Indian-arranged marriages were similar and both displayed lower synchrony than American couples. These findings suggest that emotional experience between partners may be influenced by the boarder culture, irrespective of marriage type. Taken together, these papers provide evidence for when emotional coordination between couples can have beneficial or detrimental effects on the relationship, depending on individual, dyadic and cultural factors.