Cardiac synchrony, peer relationships, and affective experiences in children during group interactions.

The current study focused on the affective and physiological processes that may emerge during children’s dyadic peer interactions in groups. We hypothesized that physiological synchrony, the correspondence of physiological processes between individuals, would be associated with both the quality of the relationship and children’s individual and shared affective experiences. We tested this hypothesis in our sample of 187 children (mean age = 11.32, SD = 0.69), who arrived at the laboratory in groups of 4 to 6 individuals from the same classroom. During their interactions, we assessed all pairwise combinations within each group, resulting in 243 dyads with complete data. Before and after the group interaction, participants reported on their pre-established dyadic relationship quality with each group member (liking, closeness, and friendship), and reflected on their individual and shared affective experiences before the experiment and their affective experiences throughout the experiment using an Affect Grid measure. Participants listened to and discussed a story about the social exclusion of a peer. Heart rate was measured throughout the experiment using a one-channel ECG, and synchrony was calculated for each dyad using high-frequency (HF) and low-frequency (LF) cross-wavelet power. The results indicated increased LF synchrony in friends compared to non-friends. In contrast, dyads showed reduced HF synchrony when experiencing more positive affect. Exploratory results further suggested that synchrony may vary depending on different types of affective experiences for friends and non-friends. We discuss how physiological processes may be informative about the quality of short-term interactions and friendship patterns during peer group dynamics.