Exploring Curvilinear Relationships of Transformational and Engaging Leadership with Stress. Is Engaging Leadership Any Better?

Leadership is typically assumed to benefit employee well-being; however, recent research suggests that even positive leadership behaviors may not be uniformly beneficial. Drawing on conservation of resources theory and Warr’s vitamin model, the present study examines whether transformational leadership and engaging leadership display linear or curvilinear relationships with employee stress outcomes. Using survey data from 766 employees across six Belgian organizations, we investigated associations with emotional exhaustion and sleep deprivation. Results indicated significant negative linear relationships between both leadership styles and stress outcomes. In addition, transformational leadership showed statistically significant but small curvilinear (U-shaped) relationships with emotional exhaustion and sleep deprivation, whereas engaging leadership was exclusively linearly related to both outcomes. Supplementary analyses examining incremental validity showed that engaging leadership explained unique variance in stress outcomes beyond transformational leadership. Overall, the findings suggest that leadership grounded in employees’ basic psychological need satisfaction may be less susceptible to diminishing returns in relation to stress. Theoretical and practical implications for leadership research and development are discussed.