How perceived mate value discrepancies are related to jealousy, mate guarding, intrasexual competition, and partner conflict in monogamous and consensually non-monogamous relationships

Mate value discrepancy (MVD)—the perceived difference in desirability between partners based on traits like appearance, personality, and status—has been linked to greater conflict and jealousy in monogamous relationships. However, no research has examined whether similar patterns occur in consensually non-monogamous (CNM) relationships, where partners consent to romantic or sexual relationships with others. In this study, participants in monogamous (n = 312) and CNM (n = 200) relationships who were recruited through social media advertisements and snowball sampling, reported their own and up to two partners’ MV, how often they experience conflict, jealousy, perform mate retention with each partner, and whether they perceive same-sex relationships as competitive (i.e., intrasexual competitiveness). We also examine whether people who have more experience with CNM, or engage more often in common CNM relationship maintenance practices, report less conflict, jealousy, mate retention, and competitiveness. Across relationship types, participants who rated themselves lower in mate value (MV) reported more conflict and intrasexual competitiveness with their primary partner. For those in CNM relationships, perceiving oneself as higher in MV than a secondary partner predicted greater conflict, jealousy, and mate retention. CNM relationship maintenance practices, such as disclosure of extra-pair attractions, comfort discussing jealousy, compersion, and shared extra-pair sexual experiences were associated with reduced conflict and jealousy. In contrast, endorsement of partner hierarchy, or the tendency to prioritize certain partners over others, was associated with more conflict, jealousy, and mate retention. These findings suggest that while self-perceived MV may shape relational dynamics, relational outcomes may be buffered or intensified by individual differences in relationship experience, and engagement in relationship maintenance practices.