An appraisal-driven emotional reward approach to unpacking prosocial behavior under varying task difficulty

Prosocial behavior is widely recognized for its benefits. Promoting it as a preferable trait is likely to yield positive outcomes. Yet, such a generalization would not be effective for understanding its construct, as research increasingly shows its multifaceted nature. It is also shaped by a wide range of factors, with task difficulty being particularly important in ecological settings. Although prior work has shown that this demand can lead to proself bias or disengagement, it remains unclear how to account for this variation across individuals and how it operates when the benefit is neither only self- nor other-directed but mutual. Here, we adopted an appraisal-driven emotional reward approach to examine the self-other tension of benefit more comprehensively across degrees of task difficulty. To provide an empirical basis for this account, multi-agent experimental sessions were conducted, where each involved 3-5 participants. They completed multiple trials of a modified effort-based slider task to earn a monetary reward benefiting themselves, an anonymous partner, both, or none (the control condition). In each trial, they also rated their perceived importance (PI) in succeeding at the beginning and satisfaction (SAT) afterward. With data from 51 qualified participants, the results validated that both the benefit conditions and task difficulty significantly alter SAT. Notably, PI profiles across benefit conditions remained relatively stable across levels of task difficulty, in contrast to SAT. Satisfaction tracked PI, aligned with appraisal theories, but only in the easy-task condition. The two appeared negatively correlated in the difficult-task condition. This effect of task difficulty on changing the PI-SAT dynamics should raise caution that prosocial tendencies assessed in lab-based situations—relying on data from successful trials—may be limited in explaining prosocial actions in real-life contexts, which are generally accompanied by task challenges and demands. In addition, a process-level investigation was conducted using moderated mediation analysis to examine causal relationships among PI, SAT, and success rate (SR), as formulated by the appraisal-driven approach. The results suggested potential mediation and moderation effects of SR. Taken together, this study demonstrated that prosocial behavior unfolded differently across levels of task difficulty and proposed an appraisal-driven emotional reward framework that could be evaluated to examine prosocial dynamics in more ecological settings.