Ego Depletion and Self-Control Failures: Resource Depletion or Changes in Motivation?_x000C_
Using self-control leads to ego depletion, a state whereby people are temporarily less successful at self-control. But the mechanisms underlying ego depletion remain debated. We tested the resource model (Baumeister, Vohs, & Tice, 2007) and motivation-based accounts of ego depletion (e.g., Inzlicht, Schmeichel, & Macrae, 2014). To manipulate resource depletion, participants (n = 78) initially completed either a non-depleting or depleting Stroop task. To test the role of motivation, we manipulated the Stroop task’s perceived difficulty: participants within each Stroop condition were misled into believing that the task was either easy or difficult. Contrary to the resource model’s predictions, participants who completed the depleting (vs. non-depleting) Stroop task did not perform worse on a second self-control task. But consistent with motivational-based accounts, those who believed the Stroop task was difficult (vs. easy) performed worse on the second task. No effect was observed on approach motivation. Taken together, our findings are more readily accommodated by motivational models. Future research should investigate the precise motivational mechanics underlying ego depletion.