Social group membership and biomarkers of health

The benefits of group membership for self-reported measures of health are well documented; however, the processes by which they can influence biological health outcomes via cardiovascular and neuroendocrine responses to stress, remains under explored. In the present study, we aim to address this gap by examining if belonging to a social group affects cardiovascular (systolic and diastolic blood pressure, and heart rate) and cortisol reactivity to stress. Using secondary data from the Pittsburgh Cold Study, 213 healthy adults (123 men, 90 women; M_age = 30.13, SD = 10.85) underwent a standardized laboratory stress-testing session. During the 2.25 h session, participants completed psychometric measures including the Social Network Index (Cohen, 1997), while biological measurements were assessed noninvasively using the Critikon Dynamap Monitor. Results showed that participants who belonged to a social group demonstrated enhanced patterns of cardiovascular adaptation to stress (i.e., peak responding at initial stress exposure, then gradual decline). This suggests that those who belong to a group have greater physiological stress tolerance, thus indicating the benefits of group membership for biomarkers of health in the long term.