The Autonomic Physiology of Terror Management: Investigating the Effects of Self-esteem on Vagal Tone

by Martens, Andy.

Theory and research suggests a link between self-esteem and cardiac vagal tone (parasympathetic nervous system influence on the heart). A literature review suggests that vagal tone protects the body against physiological threat responding (e.g., sympathetic responding) and that vagal tone is highest when we feel secure. Terror management theory posits that humans, who live in a largely symbolic world, derive feelings of security and protection from threat by way of acquiring and maintaining selfesteem. Thus we hypothesized that if vagal tone provides physiological security, and we derive a sense of security through symbolic means by way of self-esteem, then high or increased self-esteem should lead to high or increased vagal tone. To test this hypothesis we conducted two studies in which we manipulated self-esteem by giving participants positive or negative feedback. We predicted that positive feedback would lead to higher vagal tone than negative feedback. Consistent with these predictions, in both studies we found indications that positive feedback increased vagal tone relative to negative feedback. In Study 2, to more fully test our theoretical perspective we induced threat by leading participants to believe they would receive electric shocks. We predicted that both self-esteem and vagal tone would buffer against sympathetic threat responding. Consistent with our model we found that the positive feedback eliminated the sympathetic response to threat of shock that was elicited in the negative feedback condition. Also consistent with our model, higher vagal tone predicted lower sympathetic responding to threat of shock. We discuss future directions for this research and implications for physical health. 10