Physiological reactivity and habituation to acute psychological stress: The influence of trait extraversion

BACKGROUND AND AIMS: Adaptive physiological responses to stress have been suggested as a potential mechanism facilitating the association between extraversion and positive health outcomes. The present study examined the influence of extraversion on physiological reactivity and habituation to a standardized psychological stress task presented as two separate laboratory sessions approximately 48 days apart. METHODS: The present study utilized data from the Pittsburgh Cold Study 3. Participants in the study (N = 213, mean age = 30.13, SD = 10.85 years; female = 42.3 %) completed a standardized stress testing protocol twice, at two separate laboratory sessions. The stress protocol consisted of a speech preparation period (5-minutes), a public specking task (5-minutes), and a mental arithmetic task with observation (5-minutes). Trait extraversion was assessed using 10-items from the international personality item pool (IPIP). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and salivary cortisol (SC) were assessed throughout a baseline phase and the stress task phase. RESULTS: Extraversion was statistically significantly associated with larger DBP and HR reactivity in response to the initial stress exposure, as well as greater habituation of DBP, MAP and HR on repeated stress exposure. No statistically significant associations emerged between extraversion and SBP responses, SC responses or self-reported state affective responses. CONCLUSION: Extraversion is associated with greater cardiovascular reactivity, as well as pronounced cardiovascular habituation to acute social stress. These findings may indicate an adaptive response pattern amongst highly extraverted individuals and a potential mechanism leading to positive health outcomes.