Can Anyone Be An Effective Leader?

I suppose this question is like the old religious question as to whether everyone can get to heaven. It depends on your standards.

Leadership traits can be taught lecture-style. They can be practiced simulation-style. The student can subsequently be assigned into a position of real leadership. Will that leader be effective, even after decades of experience?

As a practical matter I'd say that not everyone can be an effective leader, almost regardless of your definition. To be effective at something you need passion. Passion comes from wanting something strongly. And not everyone wants the responsibility of leadership.

When I worked in a corporation we had several employees who were excellent analysts, with no desire to lead. The irony is that some of those employees had co-workers who would gladly have followed them; by some definitions a leader is one who has followers. But these employees did not want to lead, except by example.

I see it as good that not everyone wants to be a leader. Leadership is exciting to some, and unpleasant to others; vital non-leadership roles are exciting to some and unpleasant to others. The diversity helps keep all roles filled an everyone happy.