Leadership across levels: Levels of leaders and their levels of impact

This article assesses 25. years of empirical leadership research in 11 top journals with the goal of understanding current practice and future needs for drawing solid conclusions about leadership at different hierarchical levels of the organization, as well as leadership's effects on individuals, teams, units and organizations. We summarize the hierarchical level of leader and outcome level of analysis studied in different theoretical perspectives on leadership (traits, behavioral, transformational, LMX, strategic, shared) and by journal outlet. Among our findings, we observe that significantly less attention has been devoted to team- and unit-level emergent processes and outcomes, despite its conceptual relevance for leadership theory and practice. Four critical opportunities for advancing leadership science are presented.