What makes an effective leader? This question is a focus of my research as an organizational scientist, executive coach, and leadership development consultant. Looking for answers, I recently completed the first round of a study of 195 leaders in 15 countries over 30 global organizations. Participants were asked to choose the 15 most important leadership competencies from a list of 74. I’ve grouped the top ones into five major themes that suggest a set of priorities for leaders and leadership development programs. While some may not surprise you, they’re all difficult to master, in part because improving them requires acting against our nature.