Objective: Social relationships can have positive and negative influences, and these associations are particularly pronounced in old age. This study focuses on everyday interpersonal physiological dynamics (cortisol synchrony) in older couples and investigates its associations with partner presence, positive daily partner interactions, and empathy.
Methods: We conducted coordinated multilevel analyses using data from two samples of older couples from Vancouver, Canada, and Berlin, Germany (study 1: n = 85 couples aged 60-87 years; study 2: n = 77 couples aged 66-85 years), who completed questionnaires and provided salivary cortisol samples five to seven times daily for 7 days.
Results: Significant dyadic covariation in cortisol (synchrony) was present across studies (study 1/2: b = 0.04/0.03, p < .001/.001). Partner presence was only associated with greater cortisol synchrony in study 1 (b = 0.06, p = .003) but not in study 2 (b = 0.02, p = .187). Cortisol synchrony was higher when partners reported prior positive socioemotional partner interactions (study 1: b = 0.09, p = .005; study 2: b = 0.04, p = .005). There was no statistically significant association between cortisol synchrony and empathic concern (b = 0.01, p = .590) or perspective taking (b = 0.02, p = .065).
Conclusions: Moments of social bonding are intertwined with physiological synchrony in everyday life. The implications of potential repeated transmission of stress in the context of high synchrony for individual health and relationship functioning warrant further investigation.