In the era of mobile internet, people inevitably find themselves frequently in a multitasking state and are likely to receive online invitations to participate in social projects, such as charity or environmental initiatives. This study examines the effect, mechanism, and boundary conditions of multitasking as a situational factor on the subsequent prosocial behaviors of individuals. This study proposes the following hypotheses: 1: The thinking foucus reverses the effect of multitasking on prosocial behavior. When individuals focus on processes, multitasking reduces their engagement in prosocial behaviors. When individuals focus on outcomes, multitasking increases their engagement in prosocial behaviors. 2: Self-efficacy plays a mediating role in the interaction between multitasking and thinking focus on prosocial behavior. 3: Task feasibility moderates the interaction between multitasking and thinking focus on prosocial behavior intentions. When tasks are feasible, the aforementioned interaction effect remains valid. However, when tasks become infeasible, adverse outcomes directly reduce individuals' intentions to engage in prosocial behavior, resulting in the loss of the interactive effect of multitasking and thinking focus on prosocial behavior. This research conducted a series of experiments to validate its hypotheses. Study 1a (preregistered) and 1b manipulated independent variables by using the situational imagination and recall method. Study 1c applied simulated real-world tasks to manipulate multitasking to verify the main interaction effect of multitasking and thinking focus on prosocial behavior participation. Study 2 measured the intermediate variable to validate the full model of the mechanism underlying the above interaction effect. Studies 3a and 3b (both preregistered) once again confirmed the mediating role of self-efficacy by using a process-by-moderation approach. Study 4 tested the boundary conditions of the theoretical model: the moderating effect of task feasibility (feasible vs. infeasible). Research results indicate that when individuals focus on processes, multitasking (vs. single-tasking) reduces their willingness to participate in prosocial behavior (Studies 1a, 1b, 1c, 2, 3b, and 4). However, when individuals focus on outcomes, multitasking (vs. single-tasking) actually increases their willingness to engage in prosocial behavior (Studies 1a, 1b, 1c, 2, 3a, and 4). Additionally, this study verified the mediating role of self-efficacy in the above interaction effect through two methods: measurement of mediation (Study 2) and process-by-moderation approach (Studies 3a and 3b). That is, when individuals focus on processes, multitasking lowers their self-efficacy, subsequently reducing their engagement in prosocial behaviors. On the other hand, when individuals focus on outcomes, multitasking enhances their self-efficacy, subsequently increasing their engagement in prosocial behaviors. This study also indicates that task feasibility is an important boundary condition. When tasks are feasible, the effects proposed in this work are valid. However, when tasks become infeasible, adverse outcomes directly reduce individuals' intentions to engage in prosocial behavior, and the interactive effect of thinking focus and multitasking on prosocial behavior disappears. This study makes several theoretical contributions. First, this study, for the first time, demonstrates that multitasking, as a situational factor, influences individuals' subsequent prosocial behaviors. This work thereby expands the domain of research on multitasking to its effect on a domain-unrelated decision for the first time. This study also investigated the role of multiple moderating variables, such as thinking focus and task feasibility, effectively integrating seemingly disparate and contradictory findings in the field of multitasking. Second, this study further enriches the research on the effect of unrelated dynamic situational factors on prosocial behavior in the era of mobile internet. Third, this study expands the existing research related to thinking focus. The findings of this project can offer valuable guidance for designing activities that promote prosocial behavior among the public while considering the dynamics of multitasking states.
