The importance of recovery from stress is evident in times of high prevalence of stress-related diseases. Intimacy has been found to buffer psychobiological stress reactivity, suggesting that emotional and physical closeness might trigger biological mechanisms that underlie the health-beneficial effects of couple relationships. Here, we investigated whether couples' spontaneous expression of intimacy before and after psychosocial stress exposure in the laboratory reduced cortisol reactivity and accelerated recovery.
Data from 183 couples (366 individuals) were analyzed. Couples were randomly assigned to one of the following three experimental conditions: only the female partner (n = 62), only the male partner (n = 61), or both partners were stressed in parallel (n = 60) with the Trier Social Stress Test. Couples' behavior was videotaped and coded for expressions of intimacy, and saliva samples were taken repeatedly (nine times) to analyze cortisol levels before and after stress. Data were analyzed using hierarchical linear modeling.
Observed partner intimacy reduced cortisol responses to stress in women (B = −0.016, SE = 0.006, p = .008), although this effect was eliminated among women using oral contraceptives. Observed partner intimacy also reliably accelerated cortisol recovery in men (B = −0.002, SE = 0.001, p = .023) and women (B = −0.002, SE = 0.001, p = .016).
Spontaneous nonverbal expressions of intimacy seem to regulate the effects of acute environmental demands on established biological indices of stress response.
From the Institute of Medical Psychology (Ditzen), Center for Psychosocial Medicine, Heidelberg University, Heidelberg, Germany; Department of Psychology (Germann, Heinrichs), Laboratory for Biological and Personality Psychology, University of Freiburg, Germany; Department of Psychology (Meuwly), Clinical Family Psychology, University of Fribourg, Switzerland; Department of Psychology (Bradbury), University of California, Los Angeles, California; Department of Psychology (Bodenmann), Clinical Psychology for Children/Adolescents and Couples/Families, University of Zurich, Zurich, Switzerland; and Freiburg Brain Imaging Center (Heinrichs), University Medical Center, University of Freiburg, Freiburg, Germany.
Address correspondence to Beate Ditzen, PhD, Institute of Medical Psychology, Heidelberg University, Bergheimer Str. 20, 69115 Heidelberg, Germany. E-mail: firstname.lastname@example.org. Markus Heinrichs, PhD, Department of Psychology, Laboratory for Biological and Personality Psychology, University of Freiburg, Stefan-Meier-Strasse 8, 79104 Freiburg, Germany. E-mail: email@example.com
Ditzen and Germann contributed equally to this work.
Received for publication October 4, 2017; revision received June 29, 2018.