Aligning with the good in urgency: The enhanced prosocial influence under high time pressure

Prosocial behavior is essential for enhancing human welfare, particularly in urgent situations. This study employed computational models and fMRI to examine how prosocial influence affects helping behaviors under varying levels of time pressure. Participants were tasked with deciding whether to reduce electric shocks to strangers at their own expense, influenced by varying levels of time pressure (high or low) and social influences (prosocial or selfish choices made by others). Both results of study 1 (n = 31) and study 2 (n = 39) showed that prosocial influence significantly increased helping tendencies, especially under high time pressure. The hierarchical drift diffusion model demonstrates that under high time pressure, prosocial influence accelerates evidence accumulation toward prosocial choices, while a conflict emerges between prosocial priori information and the process of evidence accumulation under low time pressure. Neural correlates also indicated distinct activation patterns associated with prosocial influence under high and low time pressures: heightened affective-related activation in the insula and medial cingulate gyrus under high pressure, and increased activation in the valuation related caudate nucleus, with altered connectivity to the lateral prefrontal cortex under low pressure. In urgent contexts, witnessing altruistic actions of others significantly enhances helping behaviors through increased activation of empathy-related neural regions. Conversely, in non-urgent situations, the impact of prosocial influence diminishes, as evidenced by changes in neural activity. These findings underscore the critical role of social influence in fostering prosocial behavior during emergencies, highlighting the importance of immediate action in urgent contexts.