Socioeconomic Status and Cortisol Concentrations during a Social-Evaluative Stressor: Associations with Emotional Reactivity

Abstract

The Reserve Capacity Model suggests that individuals from low socioeconomic status (SES) backgrounds are more reactive to stress. However, SES has been inconsistently associated with cortisol responses to acute stressors. This study examined how SES affects emotional and cortisol reactivity to an acute social-evaluative stressor. We hypothesized that low SES individuals would show more emotional reactivity during the stressor, higher peak cortisol, and elevated cortisol an hour after the stressor. Participants were adults from the Pittsburgh Cold Study 3 (N = 213, M = 30.1 yrs., SD = 10.9, 57% male). In the laboratory study, participants underwent the Trier Social Stress Task (TSST) and provided seven salivary cortisol samples throughout the task. The current analyses focused on concentrations of peak cortisol (+10 minutes) and final samples (+50 minutes) as proxies for estimating physiological reactivity and recovery to the stressor. Emotional reactivity was captured through one item asking about feelings of nervousness during the stressor. SES was calculated as composite score combining income and education. Covariates included age, sex, race, and baseline cortisol concentration. All variables were collected prior to virus exposure. Low SES was associated with high emotional reactivity during the TSST, but not with cortisol peak or final concentrations. Emotional reactivity significantly mediated the relationship between low SES and elevated peak cortisol but not final cortisol concentrations. Findings from the present study suggest that SES predicts emotional reactivity to a laboratory stressor which, in turn, predicts cortisol reactivity to said stressor.