The less the better? The effects of changes in illegitimate tasks on exhaustion and uncertainty

Illegitimate tasks – those perceived as unnecessary or unreasonable – are a common source of workplace strain. Although prior research has established a robust link between illegitimate tasks and emotional exhaustion, it has largely treated such tasks as static or isolated events, overlooking their dynamic nature. This study investigates how fluctuations in illegitimate tasks – both increases and decreases – affect employee well-being relative to a stable level of such tasks. Drawing on a cognitive resource perspective, we assume that previous experiences act as critical reference points, shaping how employees perceive and react to current tasks. Across two studies using (daily and weekly) experience sampling methodology, we examine how changes in illegitimate tasks over time influence emotional exhaustion and whether this relationship is mediated by uncertainty. Our results indicate that, compared to constant levels, changes in illegitimate tasks – even decreases – lead to increases in emotional exhaustion. This underscores that less is not always better. Additionally, our findings demonstrate that uncertainty mediates the relationship between illegitimate tasks and emotional exhaustion, underscoring the cognitive costs associated with these tasks. By adopting a dynamic perspective, this study advances the understanding of illegitimate tasks and offers practical insights for organisations, particularly regarding communication strategies to reduce uncertainty and mitigate long-term effects such as burnout.