The Implications of Being "In it Together": Relationship Satisfaction and Joint Health Behaviors Predict Better Health and Stronger Concordance Between Partners.

Background: Extensive evidence shows that satisfying marriages boost physical health and longevity. A separate literature reveals strong concordance in couples' health, but the relationship processes that contribute to health concordance remain poorly understood.

Purpose: The current study examined whether relationship satisfaction and joint health behaviors-the extent to which couples eat, sleep, and exercise together-are associated simultaneously with better health and greater health similarity between partners.

Methods: Heterogeneous variance multilevel models were applied to data from 234 married couples (Mage = 46, Range = 20-84) reporting on their relationship satisfaction, joint health behaviors, and four health indicators-health satisfaction, depressive symptoms, comorbidities, and medication use.

Results: More satisfied couples engaged in more joint health behaviors than less satisfied counterparts. When joint health behaviors and relationship satisfaction were examined as separate fixed effects, both predicted greater health satisfaction and fewer depressive symptoms. More joint health behaviors were also associated with less medication use. When both were modeled together, only relationship satisfaction predicted depressive symptoms. By contrast, in random effects, joint health behaviors predicted greater similarity in health satisfaction, depressive symptoms, and comorbidities. Relationship satisfaction only predicted more similar depressive symptoms.

Conclusions: Although more satisfied couples engaged in more joint health behaviors. relationship satisfaction and joint health behaviors uniquely predicted couples' health quality and concordance, suggesting that distinct mechanisms may drive better health and stronger health resemblance.