There is a really interesting post titled "Career Success Through Engagement at Work" on a blog by Clarice Hubler. She cites Gallup research about Employee Engagement. http://claricehubler.rayonu.com/2010/05/25/career-success-through-engagement-at-work/
The thing about leadership is that it is essential to be able to engage your employees. Even if you do not have direct reports, it is can be helpful to actually engage anyone you work with. It's different in some ways, when it is a colleague, but we work in teams and partnerships, in connection with one another and we either engage or disengage each other.