Locus of Control Predicts Cortisol Reactivity and Speech Performance in Response to Acute Stress in Undergraduate Students
Abstract Previous studies have found that an individual's perception of control in a situation (Locus of Control; LOC) can serve as a protective factor that has physiological and psychological benefits. The present study examines LOC in an acute stress paradigm to examine the relationship between LOC and hypothalamic-pituitary-adrenal axis functioning as well as between LOC and performance. One hundred and thirteen participants at a metropolitan university were randomly assigned to either a stress or control condition. The stress condition consisted of the Trier Social Stress Test (TSST) while the control condition consisted of viewing a neutral travel video. Salivary cortisol was measured at four time points before and after exposure to the assigned condition. A mock job interview speech in the TSST was recorded and evaluated for performance on eight dimensions. LOC significantly predicted cortisol reactivity to the stressor in a multiple linear regression model. In addition, LOC was a significant predictor of speech performance in a simple regression model. Cortisol was not related to speech performance, and LOC did not moderate this relationship, although LOC uniquely predicted speech performance. This research adds to a growing body of literature demonstrating physiological and functional influences of LOC orientation. Keywords: locus of control, acute stress, cortisol, undergraduate students, Trier Social Stress Test, speech performance ********** Although usually assumed to be only deleterious, stress has the potential to enhance, hinder or show no impact on the performance of an individual. How well individuals do in stressful situations, such as workplace performance reviews, test-taking, and formal presentations often depend on their perception of control and mastery. Stressful situations also activate the acute stress response, known as the body's "fight or flight" response, a physiological and psychological response to physical and social demands. Many factors may influence the impact of stress, including detrimental or beneficial outcomes. Although perception of mastery seems to play an important role in success, it is not the only factor that is influential because the biological stress system may be still present and active. Both perception of control and mastery and the biological response have the potential to interfere with cognition and performance. While the literatures in both camps have developed separately, there is a need for understanding in their integration. An individual can view a situation as a result of external or internal forces, known as one's Locus of Control (LOC). LOC scores fall on a continuum between internal and external orientations. Lower LOC scores, or an internal orientation, indicate that one feels self-empowered and in control of his or her environment. Higher LOC scores, or a more external orientation, indicate that the individual feels they have less control of their environment and that outside forces shape his or her experience (Rotter, 1966). The extent of control individuals believe they have over their environment (LOC) can influence perceived stress levels, such that a greater perception of control is related to lower perceived stress (Anderson, 1977; Hellhammer, Wust, & Kudielka, 2009; Roddenberry & Renk, 2010). While perceived stress and physiological stress may be positively correlated, they are not extensions of one another per se (van Eck, Berkhof, Nicolson, & Sulon, 1996). Physiological stress is a result of nearly automatic cognitive and emotional appraisals of stimuli and perceived stress incorporates the individual's perceptions of their ability to handle the situation. This indicates that LOC may not be associated with physiological stress in the same pattern as it is with perceived stress. However, few studies have looked at LOC following the direct manipulation of stress. Therefore, further research is needed to determine whether perceptions of control can moderate the physiological acute stress response. …