Abstract
<p>Previous research has established that interpersonal coordination (IC) - the temporal alignment of behavior, neural activity, or physiology between individuals - is a ubiquitous feature of everyday social interaction. However, most studies have examined individual coordination modalities in isolation and linked them to either social or cognitive aspects of communication. Therefore, little is known about how multiple forms of coordination jointly contribute to different dimensions of communicative success. We adopted an integrative approach by simultaneously assessing verbal (linguistic, prosodic, and structural) and non-verbal (gaze direction, head, and upper-body movement) forms of IC during unconstrained conversations within same-sex dyads. Participants' evaluation of the interaction and their relationship with their partner were complemented by ratings from trained external observers, enabling comparison between internal and external views of communication outcomes. We also investigated three contextual factors potentially influencing IC: communication without visual access, absence of prior face-to-face interaction, and competitive vs. cooperative interaction history between the partners. We found evidence of coordination across all measured behavioral domains. Overall, external evaluations were better predicted by coordination measures than the participants' own assessments: linguistic and structural coordination predicted conversation quality and relational outcomes, whereas motion coordination was positively associated with conversation quality. In contrast, contextual manipulations and prior interaction history had only limited effects on IC. These findings demonstrate that different forms of interpersonal coordination make distinct contributions to successful social interaction.</p>