Does strong will get drained more rapidly or more slowly? Two longitudinal studies on how trait self-control relates to stress and fatigue

As psychological resources drain during prolonged goal pursuit, experiences of stress and fatigue are typically intensified. Trait self-control, as a capacity to manage psychological resources, might be associated with either slower increases in stress and fatigue (through facilitating more effective regulation) or faster increases (through dedicating more effort to committed goals). To test these competing hypotheses, we measured weekly fluctuations in self-reported stress and fatigue levels over an academic semester across two college student samples (Study 1: N = 78; Study 2: N = 102). Both studies showed that students high in trait self-control, compared with their low-self-control peers, experienced (a) less stress and fatigue at the outset of the weekly assessments, and (b) steeper increases in both measures as the semester progressed. These individuals also invested (c) more effort and time into their goals. These studies highlight more nuanced roles of trait self-control in effort management.