Keep it steady? Not only average self-control demands matter for employees’ work engagement, but also variability

Previous research has demonstrated that work-related self-control demands deplete regulatory resources and thus impair employees’ functioning. But what is more harmful to employees – facing consistent self-control demands throughout the day or frequently switching between activities that require varying levels of self-control (i.e. self-control demands variability)? To answer this question, we draw from theories of psychological contrast to propose the variability of self-control demands (i.e. changes in self-control demands within a day) as a contingency that amplifies the negative impact of daily (mean) self-control demands on evening ego depletion, which in turn spills over to next-day work engagement. This amplifying effect occurs because on days with high self-control demands variability, the contrast between unpleasant and pleasant activities at work becomes particularly salient, which requires additional self-control due to stronger experienced goal-desire conflicts. We propose that employees with high levels of burnout may be particularly vulnerable to the exacerbating effects of self-control demands variability because they suffer from chronic impairments of their ability to exert self-control. A daily diary study with 86 employees across ten days (N = 525 measurement points) largely supports our conceptual framework.