Abstract
Interpersonal physiological synchrony (IPS) between interaction partners has been studied as a marker of social connectedness and coordination. However, little is known about how such interpersonal synchrony relates to the intrapersonal coordination of individuals' own autonomic systems during team interaction. The present study examined whether IPS and intrapersonal physiological synchrony (IAPS), defined as the within-person coordination of heart rate (HR), respiration, and electrodermal activity (EDA), function as competing or complementary regulatory processes. It also examined whether IAPS is state- or trait-like and whether teams high or low in both IPS and IAPS had better outcomes. Fifty five newly formed triads (N = 165; Mage = 23.87, 77% female) participated in a laboratory interaction including passive shared experiences and active collaborative tasks while continuous physiological activity was recorded. Synchrony within individuals and between team members was quantified using multidimensional recurrence quantification analysis. Across interaction segments, IAPS was positively associated with IPS in both HR and EDA, with stronger and more consistent associations during active teamwork versus during passive social contexts. These findings contradict a trade-off hypothesis and instead support a synergistic relationship between IAPS and IPS. IAPS exhibited state-like dynamics and sensitivity to features of the context, i.e., consistency within similar interaction contexts and higher in passive versus active social segments. Further, IAPS had limited associations with individual difference measures. Exploratory analyses indicated that teams characterized by both high IAPS and high IPS demonstrated more favorable outcomes, reflected in either higher objective task performance or greater perceived team efficacy depending on physiological modality. Together, these results suggest that effective team coordination is supported not only by IPS but also by the capacity to maintain coherent internal autonomic organization. They further highlight IAPS as a dynamic component of social functioning that merits exploration alongside interpersonal processes.