There is emerging evidence for links between relationship factors and sleep quality. Existing research linking attachment orientation to sleep quality has yielded inconsistent effects, has focused on younger samples, and has not considered underlying mechanisms of action. This research addressed these gaps in two studies that investigated the links between attachment orientation and sleep quality in both younger/middle-aged (Study 1) and older (Study 2) adult couples using Actor-Partner Interdependence Models. We also tested mediating effects of relationship-specific security and negative affect. In both studies, participants completed surveys assessing their attachment orientation, sleep quality, and the proposed mediators. Both studies revealed that relationship-specific security and negative affect mediated the negative association between insecure attachment and one's own sleep quality. This research enhances our understanding of how attachment orientation affects sleep quality, provides a foundation for future research on relationship influences on sleep, and suggests avenues for improving sleep quality.
Keywords: aging; attachment; negative affect; relationship-specific security; sleep quality.