Abstract
Social relationships influence physical health, yet questions remain regarding the nature of this association. For instance, when it comes to predicting health-relevant processes in daily life, few studies have examined (a) the relative importance of both positive and negative relational experiences, and (b) variability in relational experiences (in addition to mean levels). To address these gaps, we conducted a daily study (N = 4,005; ~ 30,000 observations) examining relationships, stress, and physiology in daily life. Heart rate and blood pressure were assessed using an optic sensor and integrated with an app-based study. Results demonstrated that higher mean levels of positive and lower mean levels of negative relational experiences predicted lower stress, better coping, and better physiological functioning in daily life, such as lower systolic blood pressure reactivity. Greater variability in negative (but not positive) relational experiences predicted lower stress, better coping, and lower systolic blood pressure reactivity.