This study aims to review and quantify the value of several well-established positive leadership styles for employee work engagement in organizations. We perform both a quantitative and qualitative review (k = 86). Our (moderated) meta-analysis indicates that transformational, authentic, empowering, ethical, and servant leadership all share overlap in confidence and credibility intervals, and they may result in the same effect on work engagement (general r = 0.47). Additional theoretical analysis indicated a common ground within these positive leadership styles, i.e., having a moral perspective as a leader, role-modelling behaviour, follower self-determination, and positive social exchanges with employees. Based on the studies in the sample, we also build an integrative research model with several categories of mediators and moderators that have a well-established impact on work engagement. The moderator categories were follower characteristics and team- and organizational-level moderators. The mediator categories were psychological needs, trust, resources, and organizational-level variables. The combination of a meta-analysis with systematic review and research model can facilitate future research and supports practitioners to improve leadership.
Keywords: leadership; leadership styles; meta-analysis; research model; review; work engagement.