There is an “I” in team: Intrapersonal physiological synchrony complements interpersonal physiological synchrony in team interaction

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; M age = 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 HR, EDA, and respiration. The HR association did not differ across segments, whereas segment differences in the EDA and respiration associations were specification-sensitive. These findings contradict a trade-off hypothesis and instead support a synergistic relationship between IAPS and IPS. IAPS showed both state-and trait-like features: higher levels in passive than active contexts and relative stability across similar contexts. IAPS was not reliably associated with individual-difference measures. Exploratory profile analyses found differences in perceived group efficacy across IAPS/IPS-BPM profiles, although the pattern was not specific to the high-high subgroup and was based on small, unequal subgroups. The IPS-EDA profile test for performance did not survive correction. Together, these results suggest that intrapersonal and interpersonal physiological synchrony coexist as complementary patterns of physiological organization during team interaction. They further position IAPS as a dynamic component of social functioning that merits investigation alongside interpersonal processes.