Transformational leadership effectiveness: an evidence-based primer

The proliferation of leadership models can leave practitioners confused about which model to use in guiding their leadership development initiatives. Although ‘new’ leadership models (e.g. authentic, ethical, and servant leadership) suggest theoretical differences, empirical research has shown considerable overlap among these models and longer standing ones such as transformational leadership. With extant literature questioning the added empirical value of these newer models, this paper aims to distil the best evidence about transformational leadership into a ‘primer’ that can help practitioners use evidence-led practices in their leadership development. To do so, we briefly review major leadership models, highlight evidence for empirical redundancy between new leadership models and transformational leadership, and discuss meta-analytic findings between transformational leadership and outcomes of leadership. Our review suggests that these newer leadership models add little incremental validity beyond transformational leadership in predicting various leadership outcomes. Moreover, transformational leadership demonstrates medium to large effect sizes on a range of individual, team, and organisational outcomes. Taken together, our findings suggest that organisations can benefit by focusing their resources on transformational leadership development, rather than on the latest leadership fad.