Affiliation: College of Arts and Sciences, Department of Psychology and Neuroscience
Social closeness is inextricably tied to physical and mental health, but the psychophysiological mechanisms that link the two are not well understood. The purpose of this dissertation is to present and test a Socio-Autonomic Spiral Model of Social Closeness and Health: A proposed self-sustaining, heritable psychophysiological system in which activity of the vagus nerve promotes self-regulation and social openness behaviors in safe situations in order to achieve the social bonds necessary for survival in the evolutionary past and health in the present. Social bonds, in turn, lead to greater psychological well-being, which results in greater vagal activity and thus more social affiliative behaviors. The predictions of the model were tested in two studies. In a longitudinal study, experimentally-induced increases in social closeness predicted increased vagal tone over eight weeks, mediated by increases in positive emotions. Contrary to previous work, vagal tone did not moderate the effectiveness of the social closeness induction. In a laboratory study, vagal tone predicted decreased anxiety when anticipating a social interaction, and this effect was mediated by the tendency to preferentially attend to social stimuli, an indicator of social openness. Unexpectedly, vagal tone was not associated with self-regulation or emotion regulation. The vagus may represent an evolved psychobiological system that promotes social affiliation and health, however, many open questions remain. In particular, the relationship between vagal tone and self-regulation is unclear and requires further study. Finally, vagal moderation of social closeness inductions may be dependent on the complexity of the induction; future research can explore the characteristics of opportunities that are enhanced by vagal tone.