BackgroundHuman conversation involves moment-to-moment reciprocal adjustments between interlocutors, expressed through both emotional cues and autonomic physiology.ObjectivesTo quantify how physiological synchrony continuously builds and subsides between debate partners during speaker-listener turn-taking, and to test whether the direction of this coupling (speaker-leading vs listener-leading) is associated with (i) self- versus partner-perceived arousal/valence and (ii) autonomic and complexity