Social relations are broadly defined as any relationship or interaction between two or more individuals. Interest in social relationships and resulting support began a century ago when the French sociologist Emile Durkheim postulated that disruptions in social networks could influence psychological health.[1] Consequently, theoretical models have emerged that conceptualize social support as a multifaceted construct. Models typically include the concepts of social integration, or level of involvement in relationships, such as marriage or group membership, and the emotional, tangible or practical support from others that serves a functional purpose.[1][2] An individual’s acknowledgment or fulfillment of social roles may beneficially influence self-esteem and provide a sense of meaning or controllability to life.[3] It is also important to consider the converse, or social conflict, as there are important consequences to emotional and physical health for the socially isolated individual, one who lacks social connections, or those for whom relationships serve as a source of stress.[1][2]

Social Relations and Stress

A widely accepted view of psychological stress defines it as the appraisal of an event as taxing or overwhelming one’s resources (Lazarus & Folkman, 1984. Stress, appraisal, and coping. New York, NY, Springer). This theory first proposed that appraisal of an event as threatening or exceeding one’s resources activates physiological stress response systems in the body, including the autonomic (fight or flight) system and hypothalamic-pituitary-adrenal (HPA) axis.[4]

The hypothalamic-pituitary-adrenal (HPA) axis responds to central nervous systems signals that regulate the release of the glucocorticoid hormone, cortisol, from the adrenal gland. In a healthy individual, circulating cortisol levels double within 30 minutes to 45 minutes after awakening and then gradually decrease over the course of the day and subsequent night,[5] reflective of the diurnal slope. As a primary conductor of the physiological stress response, psychological stress also activates the hypothalamic-pituitary-adrenal axis. When a stressor lasts for more than a few minutes, increased levels of cortisol are released from the adrenal cortex. When a stressor or repeated stressors become chronic, lasting for periods of months to years, the over-taxed HPA axis becomes less able to respond flexibly to environmental demands. This results in long-lasting dysregulation of axis functioning, which can manifest as erratic peaks and troughs in diurnal cortisol expression.

Social relationships that are perceived as emotionally supportive have demonstrated their potential to act as a buffer of the effects of stress. Social support makes the demands of a stressor feel more manageable, thereby buffering its impact.[6][7] As such, social support may provide some protection to the hypothalamic-pituitary-adrenal (HPA) axis responsivity. In fact, simply being married may be protective of the HPA axis function. In a community sample, married individuals had healthier appearing cortisol rhythms than their never married or previously married counterparts. Interestingly, the relationship between high stress and cortisol disruption appeared to be diminished among married individuals.[8] Marital satisfaction was not assessed. This suggests that even those who are dissatisfied in their marriages may still experience benefits. This may be in part related to increased access to healthcare/insurance or growing social networks, both of which often accompany marriage.

While the size of an individual’s social network, or integration, may not be associated with diurnal cortisol secretion or acute stress responses, supportive relationships have been associated with more rhythmic or healthy-appearing diurnal cortisol expression profiles.[9][10] Alternatively, it has been noted that when one feels isolated or less integrated into social networks, the associated increased psychological stress appears to amplify physiological stress responses.[11] Social isolation has been associated with dysregulation of diurnal cortisol expression in several studies of healthy adults.[12][13]

The impact of the social world on physiology and health is a topic of intrigue to scientists in a variety of disciplines. Social interactions may exert direct effects on biological functioning by providing a zeitgeber (i.e., time-giver) to set or reset our biological clocks.[14] Social integration may directly and positively influence health behaviors. Integration also promotes social embeddedness, defined as ongoing social connectedness that facilitates beneficence toward self and others, which may positively affect health.[15]

Societal roles, for example, the social role of a mother or spouse, may provide one with a sense of social identity and thereby influence health behaviors, such as exercising or smoking cessation. The provision of information regarding the importance of treatment adherence may be another way in which our social structure exerts a direct impact.

Physiological stress response systems tend to become less efficient with age. Chronic or frequently repeated stress response activation stress may also bring about hypothalamic-pituitary-adrenal dysregulation. This affects the responsivity of the axis, reducing the flexibility of the hypothalamic-pituitary-adrenal stress response mechanism. Chronic dysregulation of these systems may hamper the body’s natural disease defenses. As a result, psychological stress may be implicated in disease onset, development, and course.[16]

Individuals reporting better social support demonstrate preserved hypothalamic-pituitary-adrenal axis efficiency, an association that may be even more pronounced among older males.[17] Greater social integration has also been shown to reduce disease and mortality risk.[18] Supportive relationships may be beneficial for cardiovascular health, endocrine and immune function, and protection from disease development.[19] A recent example highlights these effects: a study utilizing a large epidemiological cancer database (SEER data) revealed that unmarried cancer patients are at greater risk for presentation with metastatic disease, under-treatment of illness, and increased risk of death.[20]

Social Relationship Interventions

Existing social relationships appear to exert a strong impact on the psyche and physiology. Understandably, attempts to increase these factors have garnered significant attention in recent decades. Social support interventions by nature work to "mobilize the social environment" to meet an individual's needs better.[21] Social support interventions typically focus on at least one of the three main attributes. They change the structure or composition of the social field, change attitudes or behavior toward the social field, or change the quality and frequency of support received.[22] Promising studies have also demonstrated that these types of interventions may benefit endocrine and immune physiology in patients with cancer.[23] Future research will be useful for a better understanding of the mechanisms by which social relationships are most effective at conferring psychological and physiological benefits. Similarly, public health policy initiatives that promote social relationships may beneficially impact health.