 Howell and colleagues added enhancers to these.Substitutes for leadership theory was a heavily researched area until the late 1980s, when transformational leadership became the focus of the majority of leadership research (Dionne, Yammarino, Howell, & Villa, 2005).Substitutes for leadership theory states that different situational factors can enhance, neutralize, or substitute for leader behaviors (Avolio et al., 2009; Den Hartog & Koopman, 2001).