Abstract
Previous research suggests that social avoidance behavior (SAB) serves as a transdiagnostic mechanism that underlies numerous phenotypes of psychopathology. Dual-process models propose automatic action tendencies and regulatory processes to approach or avoid affective facial expressions contribute in parallel to SAB. However, no research to date has examined the relationship between SAB and automatic action tendencies to affective facial expressions. Additionally, past research has exclusively used stereotypic facial expressions communicating intense social reward (100%Happy) or social threat (100%Angry), which are not ecologically valid or sensitive to individual differences. Instead, social communication is characterized by ambiguous facial expressions that communicate varying degrees of social reward-threat conflict (50%Happy/50%Angry), social reward (e.g. 50%Happy), social threat (e.g., 50%Angry). To address these issues, this dissertation aimed to characterize SAB-related modulation of automatic action tendencies and neural activation to ambiguous facial expressions. Across three studies, we observed that SAB was consistently and specifically associated with behavioral modulation of automatic avoidance actions in response to social reward-threat conflict. In an fMRI experiment (Study 3), we observed SAB-related modulation of amygdala activation in response to social reward-threat conflict. Based on these collective results, we propose that SAB stems from a complex interaction between automatic action selection and motivational states elicited by social reward-threat conflict.