Beyond the straight line: A literature review and threshold framework of nonlinear leadership effects

Leadership research has largely been built on the assumption that leadership behaviors exert linear and sign-consistent effects on organizational outcomes. However, converging evidence indicates that these relationships are often nonlinear, such that the same leadership style can produce both beneficial and detrimental outcomes depending on its intensity and contextual conditions. Despite these insights, research on nonlinear leadership effects remains theoretically fragmented and empirically under-integrated, lacking a coherent explanation of when, why, and in what forms such effects emerge. To address this gap, we conducted a systematic analysis of 60 empirical studies on nonlinear leadership effects across task-, relation-, and change-oriented as well as destructive leadership styles. We integrated evidence on functional forms, mediating mechanisms, moderating conditions, and methodological approaches. This analysis identifies consistent empirical patterns while revealing systematic limitations in the explanatory scope of existing theoretical perspectives. Building on this integrated assessment, we developed a leadership intensity threshold framework that conceptualizes leadership intensity as a continuous driver of qualitatively distinct outcome regimes. This framework specifies threshold-based mechanisms through which changes in leadership intensity produce discontinuous shifts in interpersonal dynamics. These shifts, in turn, shape the implementation and effectiveness of HR practices by line managers. By linking fragmented empirical findings with a mechanism-based theoretical account, the framework provides an organizing structure for cumulative theory development in human resource management (HRM). It advances a more precise understanding of how leadership behavior enables or constrains effective HRM implementation across contexts.