In my leadership courses and when I conduct corporate training, participants/students often point to great historical leaders' qualities as examples of successful leader characteristics. Yet, follower characteristics are critical to determining the leader characteristics that are most successful within a certain context. Leadership is only successful when followers follow!
Recent research by Adam M. Grant, Francesca Gino, and David A. Hofmann demonstrates that extroverted leaders succeed with passive employees while introverted leaders succeed with proactive employees.
What type of team do you play for? How are you leading that team?
(title source: Trina Soske and Jay A. Conger in HBR article, It's Time to Focus Executive Development on Real Business Issues. Research source: Reversing the Extraverted Leadership Advantage: The Role of Employee Proactivity)