Transformational leadership is an organizational leadership theory centered around "the ability to inspire and motivate followers to achieve results greater than originally planned and for internal reward" The investigation into transformational leadership began in the mid-1980s with a number of influential publications by Bass (1985), Bennis and Nanus (1985), Kouzes and Posner (1987) and Tichy and Devanna (1986). In the 1980s, the study of transformational leadership was focused on case-based research (Conger, 1999). By late 1990s, a substantial body of empirical investigations on transformational leadership had been conducted.
Jennifer Y. Mak and Chong W. Kim, “The Relationships Among Gender, Work Experience, and Leadership Experience in Transformational Leadership,” Midwestern Business and Economics Review, Number 43, Spring 2009, pp. 5 – 10.