Abstract
The role of oxytocin (OT) in close relationships is complex, as both positive and negative associations have been found between OT and relationship processes. Also, with most research focusing on the effects of exogenous OT administration on communication and couple behaviors, our knowledge about the association between endogenous OT and couple dynamics remains limited. This study is the first to assess the link between peripheral OT levels and observed communication behaviors during sexual and nonsexual conflict discussions in romantic relationships. A sample of 126 young, heterosexual couples (Mean age = 23.3, SD = 2.4; average relationship duration = 1.9 years, SD = 0.9) participated in videotaped sexual and nonsexual couple conflict discussions of 7 min each. Communication behaviors were coded using an adaptation of the Specific Affect Coding System (SPAFF) and the System for Coding Interactions and Family Functioning (SCIFF). Blood samples were collected prior to the couple discussions, during a separate lab visit, and OT plasma levels were determined using enzyme-linked immunosorbent assays (ELISA). Plasma OT levels were positively associated with validating behaviors during sexual discussions in both women (r = +.24, p = .008) and men (r = +.18, p = .052). No significant associations were found between OT levels and validating behaviors during nonsexual discussions and between OT and affectionate and negative behaviors during either sexual or nonsexual discussions. Analyses revealed significant associations between OT levels and one's own validating behaviors during sexual discussions (b = 47.82, t(201.16) = 3.81, p < .001) and one's partner's (b = 32.12, t(216.35) = 2.62, p = .009). The results highlight the biobehavioral aspects of couples' sexual communication and may contribute to a better understanding of the processes involved in individual and relational well-being. This study is the first to report an association between peripheral OT levels and validating behaviors during sexual communication, indicating neurophysiological involvement in dyadic sexual communication patterns.