Impact of social environment characteristics on neuroendocrine regulation.

OBJECTIVE This article reviews evidence relating social environment characteristics to patterns of neuroendocrine regulation. To date, although there has been considerable interest in the effects of social ties and support on health and longevity, less attention has been given to the effects of such social environment characteristics on actual physiologic parameters. METHOD Animal and human studies from 1960s to the present are reviewed for evidence linking social environment characteristics to patterns of hypothalamic-pituitary-adrenal (HPA) axis, sympathetic nervous system (SNS), and cardiovascular activity. RESULTS Community and laboratory-based studies document that characteristics of the social environment influence patterns of neuroendocrine reactivity. These effects seem to be highly sensitive to aspects of the social environment such as relative social status, the relative stability of the social ordering and, importantly, the quality of social relationships. Although supportive social relationships are often associated with attenuated patterns of HPA and SNS activation, the converse also seems to be true as nonsupportive social interactions are frequently associated with enhanced reactivity. CONCLUSION Available evidence regarding links between social environment characteristics and neuroendocrine regulation documents a link between the social and biological realms that may have important consequences for health and longevity. The data provide support for the hypothesis that observed associations between social ties and health and longevity result, at least partially, from the positive influence of such social environment characteristics in reducing neuroendocrine reactivity. The evidence regarding nonsupportive or hostile social relationships highlights the importance of taking a broader view of the potential health effects of the social environment, one that encompasses the potential for both positive and negative effects.