Prosocial behaviours, such as trust and cooperation, often emerge naturally during social interactions. However, it remains unclear how prosociality is initiated, particularly in anonymous settings like virtual environments. Previous studies suggest that humans can exhibit communal instinct, an intrinsic drive to process others’ information merely upon knowledge of their intentions, even without explicit social interaction or cooperations. We hypothysize that this instinct may facilitate prosocial tendency between anonymous strangers. In this study, participant pairs completed a joint Flanker task under two conditions: shared attention (knowledge of each other’s intention) and separated attention (no knowledge). A trust game followed to assess prosociality.Participants showed increased reaction time during incongruent trials in the shared attention group, implying involuntary processing of the counterpart’s information, as evidence of communal instinct. Trust game investments were significantly higher in the shared attention group, highlighting the role of communal instinct in trust-building. Neural evidence from dual-EEG hyperscanning showed enhanced synchronisation in the theta bands in the shared attention group, particularly in the frontal cortex, suggesting communal instinct may foster prosocial behaviours through enhancing frontal neural coupling. Our findings illuminate fundamental mechanisms underlying human connection and cooperation, offering critical insights for fostering social cohesion in a digital age.

Wu Wei, affiliated with the University of Science and Technology of China, focuses on cutting-edge research, advancing knowledge in their field, and actively participating in international academic and scientific communities.