Investigating the psychological processes underlying ego-depletion

Abstract

Self-control is arguably one of the most beneficial adaptations of the agentic self. It enables humans to alter spontaneous, impulsive responses in order to fit one’s goals and standards. Variations in self-control capacity are strong predictors of a wide array of individual and societal outcomes including psychological adjustment, academic achievement, physical health, financial condition, and criminality. In this respect, investigating how to prevent self-control failures is a promising way for psychologists to improve human well-being. To this end, it is important for researchers to understand why people fail to control themselves.

The limited-energy model suggests that self-control behaviors draw on a limited, depletable internal resource. People will become more vulnerable to self-control failures if the internal energy is depleted by prior use. Research demonstrates that an initial volitional act would undermine subsequent self-control performance as if the initial exertion exhausts an internal resource that is required for all self-control behaviors. This phenomenon is known as ego-depletion. Although much research lends credence to the validity of the ego-depletion phenomenon, little is known about its underlying psychological mechanisms. To fill this research gap, the present research tested a self-efficacy account of ego-depletion, which suggests that reduction in self-efficacy mediates the effect of initial self-control exertion on subsequent performance.

A series of four experiments were conducted to examine the self-efficacy account. Experiment 1 found that initial self-control exertion resulted in lower self-efficacy to regulate eating habits. Two subsequent experiments found that self-efficacy mediated the negative effect of initial self-control exertion on mental calculation performance under distraction (experiment 2) and persistence on anagrams (experiment 3). In experiment 4, self-efficacy explained how implicit theory of willpower moderated the ego-depletion effect. In particular, participants who believed that “willpower is unlimited” were less affected by ego-depletion because their self-efficacy did not decrease after initial exertion. Taken together, the current data suggest that self-efficacy is one of the cognitive processes underlying ego-depletion.

Moreover, the current research distinguishes task-specific, prospective self-efficacy from other positive beliefs such as retrospective confidence of the initial task (experiment 2 and 4), outcome expectation (experiment 3) and general confidence in one’s ability (experiment 4). It shows that among these positive beliefs, only self-efficacy serves a mediation role in ego-depletion. The current findings not only enrich the self-efficacy theory by identifying a potential source of efficacy belief, but also contribute to a fuller mechanistic understanding of self-control failures. Implications for intervention and human agency are discussed.