Objective: To review research on close relationships and health in daily life, with a focus on physiological functioning and somatic symptoms, and to present data on the within-person effects of physical intimacy on somatic symptoms in committed couples' daily life. The empirical study tested whether prior change in physical intimacy predicted subsequent change in symptoms, over and above their concurrent association. In addition, the study tested if increasing and decreasing intimacy had asymmetric effects on symptom change.
Methods: In this study, 164 participants in 82 committed couples reported physical intimacy and somatic symptoms once a day for 33 days.
Results: Prior within-person change in intimacy predicted a subsequent reduction in symptoms; when a person's intimacy increased from one day to the next day, then symptoms decreased over the following days (B = -0.098, standard error [SE] = 0.038, p = .013). This lagged effect of intimacy held over and above the association of concurrent change in intimacy and symptoms (B = -0.122, SE = 0.041, p = .004). The study found asymmetric effects of prior increase and decrease in intimacy; prior intimacy increase predicted reduced subsequent symptoms (B = -0.189, SE = 0.068, p = .047), whereas prior intimacy decrease was unrelated to subsequent symptoms (B = -0.003, SE = 0.063, not significant). There was no evidence for asymmetric effects of intimacy increase and decrease on concurrent symptom change.
Conclusions: Close relationships exert influences on health in daily life, and part of this influence is due to intimacy.