An Experimental Laboratory Investigation

This study experimentally tested whether a stressor characterized by social-evaluative threat (SET), a context in which the self can be judged negatively by others, would elicit increases in proinflammatory cytokine activity and alter the regulation of this response. This hypothesis was derived in part from research on immunological responses to social threat in nonhuman animals. Healthy female participants were assigned to perform a speech and a math task in the presence or absence of an evaluative audience (SET or non-SET, respectively). As hypothesized, stimulated production of the proinflammatory cytokine tumor necrosis factor-a (TNF-a) increased from baseline to poststressor in the SETcondition, but was unchanged in the non-SET condition. Further, the increases in TNF-a production correlated with participants’ cognitive appraisals of being evaluated. Additionally, the ability of glucocorticoids to shut down the inflammatory response was decreased in the SET condition. These findings underscore the importance of social evaluation as a threat capable of eliciting proinflammatory cytokine activity and altering its regulation. Preserving a positive social self—maintaining one’s social esteem, status, and acceptance—is central to well-being and survival (Baumeister & Leary, 1995). Therefore, conditions that threaten the social self may elicit psychological, physiological, and behavioral changes to coordinate an appropriate response to the situation (e.g., Dickerson, Gruenewald, & Kemeny, 2004). Acute social self threat, or social-evaluative threat (SET), occurs when an aspect of the self could be negatively judged by others (Dickerson & Kemeny, 2004). Previous work has demonstrated that SET triggers specific psychological and physiological changes. For example, social-evaluative stressors (e.g., delivering a speech in front of an audience) are more likely to elicit the hormone cortisol than are otherwise-equivalent stressors without social evaluation (Dickerson & Kemeny, 2004; Dickerson, Mycek, & Zaldivar, 2008; Gruenewald, Kemeny, Aziz, & Fahey, 2004). Additionally, studies have shown that increases in cortisol correlate with the self-evaluative cognitions and emotions experienced under SET, demonstrating patterned psychobiological changes (Dickerson et al., 2008; Gruenewald et al., 2004). Other physiological responses may also be elicited by SET. Evidence from nonhuman animals demonstrates that social threats can increase inflammatorymarkers; further, theremay be specificity with regard to the nature of the threat and the immunological responses observed. Proinflammatory cytokines, including tumor necrosis factor-a (TNF-a), are chemical communication molecules that orchestrate the inflammatory immune response, which is integral for fighting infection and healing from injury. Animals experiencing social threats, such as social subordination or defeat, show greater stimulated production of proinflammatory cytokines and increases in other inflammatory markers compared with animals exposed to either other types of stressors (e.g., physical restraint) or nonstressful Address correspondence to Sally S. Dickerson, Department of Psychology and Social Behavior, University of California, Irvine, 3340 Social Ecology II, Irvine, CA 92697-7085, e-mail: [email protected]. PSYCHOLOGICAL SCIENCE Volume 20—Number 1