Background: There are large individual differences in dealing with everyday social stress. Therefore, we investigated the association of social inhibition (and its facets) with the emotional and physiological responses to the Trier Social Stress Test (TSST). Methods: Undergraduate students (N = 312) completed the 15-item Social Inhibition Questionnaire (SIQ15) and participated in the TSST, while emotional and cardiovascular stress responses were recorded. We examined the effect of social inhibition across time with repeated-measures ANCOVAs. Findings: During social stress (and recovery), social inhibition was associated with increased negative mood reactivity (especially the behavioral inhibition facet) and heightened sympathetic activation (especially the social withdrawal and interpersonal sensitivity). Physiological stress reactivity seems to be mostly α-adrenergic in women, and also β-adrenergic in men. Conclusions: Emotional and physiological stress responses are associated with individual differences in social inhibition. This warrants more research on mechanisms that underlie the relations between social inhibition, stress and health.

Introduction

Research to date holds evidence of individual differences in vulnerability to social stress (e.g., Bibbey, Carroll, Ginty, & Phillips, 2015; Kret, Denollet, Grezes, & de Gelder, 2011). A maladaptive response to social threat is characterized by cardiovascular arousal (e.g., increased heart rate and total peripheral resistance (Bosch et al., 2009)) and increased negative emotional arousal (e.g., Childs, White, & de Wit, 2014; Habra, Linden, Anderson, & Weinberg, 2003). Recurrent social stress, but also elevated loneliness and social isolation, have emerged as risk factors for cardiovascular disease and premature mortality (Cundiff & Smith, 2017; Rosengren et al., 2004; Steptoe, Shankar, Demakakos, & Wardle, 2013). Individual differences in dealing with everyday social stress may be associated with social inhibition, which can be defined as “a broad and stable personality trait characterized by behavioral inhibition during social interaction, increased social-evaluative concerns, and withdrawal from intense social engagement situations” (Denollet & Duijndam, 2019). Socially inhibited adults may be more susceptible to increased levels of social stress because they are more upset at having to interact with people, and are more concerned with others’ evaluations of themselves (Denollet & Duijndam, 2019; Denollet, 2013; Marin & Miller, 2013). Previous findings indicate that during social interactions, socially inhibited individuals experience high arousal negative emotions such as anxiety and anger (Lin et al., 2017; Timmermans et al., 2019). However, less is known about low arousal negative emotions, such as sadness or fatigue, and how emotional reactivity is related to social inhibition during social stress.