Exploratory Study of Autonomic Synchrony and Subjective Opinion Change (SOC) in Moral Persuasive Interactions

Introduction: Moral persuasion engages cognitive, emotional, and interpersonal regulation processes. While autonomic synchrony has been linked to cooperation, empathy and mutual influence, its role in moral persuasion remains underexplored. This study examines how physiological synchrony – measured via heart rate (HR), heart rate variability (HRV), and skin conductance level (SCL) – is associated with the subjective perception of opinion change within interacting pairs. Methods: Thirty young adults (15 unacquainted same-sex pairs, mean age = 23.6) participated in a structured, realistic moral persuasion task while their autonomic physiological signals were recorded. Dissimilarity indices (Euclidean distance) were computed for HR, HRV, and SCL within each pair. Dyads were grouped according to Self-evaluation of Opinion Change (SOC) concordance: higher SOC (both members reported relatively higher opinion change), mixed SOC (only one reporting opinion change), and lower SOC (both reporting no opinion change). Results: HRV dissimilarity significantly differed by SOC group: mixed SOC pairs showed significantly higher HRV dissimilarity than high SOC pairs, whereas other physiological signals did not show different profiles. Discussion: Preliminary findings suggest that convergence in cardiac autonomic activity during the persuasive exchange varies as a function of the concordance of perceived opinion change. This pattern may reflect that interpersonal dynamics contribute to shaping moral interactions and autonomic co-regulation, consistent with perspectives emphasizing the social and embodied nature of moral decision-making.