This study draws on the conservation of resources theory to explore the role of altruistic behavior in resource gain and loss spirals and the association between particular genetic markers and these spirals. Using experience sampling data and genetic analysis, we found that positive affect (T1) was directly associated with altruistic behavior. A payoff of increased positive affect resulted from such behavior (T2). Individuals who started work with an elevated level of fatigue (T1) engaged in less altruistic behavior and became more fatigued (T2). Altruistic behavior mediated the positive affect/fatigue at T1 and T2. Hence, altruistic behavior may promote a resource gain spiral by enhancing positive affect resources. Furthermore, it buffers against a resource loss spiral by preventing increased fatigue. Moreover, genetic testing showed that the 2R carriers of the DRD4 polymorphism would respond with stronger positive affect and less fatigue after performing altruistic behaviors compared to non-2R carriers. Therefore, our research revealed the moderating role of individual differences in the relationship between altruistic behavior and resource gain and loss spirals.