Background: Characteristics of family life are linked both cross-sectionally and prospectively to adult mental and physical health.
Purpose: This paper discusses social and biological processes that may explain how families influence the health of their members.
Methods: We review naturalistic studies of short-term biopsychosocial processes as they unfold within the family.
Results: Day-to-day fluctuations in stressors, demands, and social and emotional experiences in the family are reflected in short-term changes in adult members' affect and in the activity of biological stress-response systems, particularly the hypothalamic-pituitary-adrenal axis.
Conclusions: To learn how family environments are linked to health, researchers should study the interlacing of different aspects of the everyday lives of family members, including their physiology, emotions, behavior, activities, and experiences.