Shared experiences of social exclusion enhance inter-brain synchronization.

Social exclusion has substantial detrimental effects on cognitive functioning and psychological well-being. However, most research on its cognitive and neural mechanisms has examined exclusion in isolated individuals, despite the fact that, in everyday life, people often experience exclusion together with others. Accordingly, this study is grounded in shared representation theory and the perception-action model. Using fNIRS hyperscanning, it aims to identify the inter-brain synchrony (IBS) patterns that arise during shared experiences of social exclusion. Behaviorally, participants who jointly experienced exclusion reported stronger feelings of rejection and lower satisfaction of basic psychological needs, along with more negative and fewer positive emotions. At the neural level, shared exclusion elicited a significant increase in IBS within the left dorsolateral prefrontal cortex (DLPFC), and this synchrony was negatively correlated with basic psychological need satisfaction. These results indicate that shared negative social events enhance neural synchrony between individuals. This synchrony may reflect shared emotional representations, concurrent demands for emotion regulation, and empathy for each other's experiences. Overall, the study provides new evidence regarding the neural basis of shared adversity in group contexts.