People have written tons of articles about what makes a great leader great. Some conclusions center around his or her intelligence, charisma, or personal drive. Researchers at Columbia University have come to a little bit of a different conclusion.

Professor Daniel Ames, with a colleague in the Management Division, Frank Flynn, centered their research on coworker evaluations of their MBA students. Former coworkers commented on the students’ strengths and weaknesses and also rated their leadership potential. When asked, “What’s holding this person back from being a great leader?” the answer that came up most often was assertiveness. This was mentioned from both sides of the coin, with some people described as too overbearing and others described as not assertive enough to stand their ground.

Ames says that the reason assertiveness comes up so often is that conflict is such an essential part of what managers and leaders deal with. He said,

“Sometimes it’s avoiding conflicts that really beg to be embraced and engaged in. Other times it’s pushing too hard and straining relationships through conflict.”

Ames also points out that there’s variance across situations as well:

“Someone who’s a real mouse to their immediate supervisor might turn around and be an absolute terror to the people who work for him or her.”

I think, too, that the motive or outcome behind “winning” has something to do with the effectiveness of assertiveness. A leader who wants to win just for the sake of winning is less effective than the leader who is going to bat for something he or she believes in. But even then, a highly assertive person (even if they’re fighting for the right reason) may not see the consequences of his behavior. For example, he doesn’t see that the person he just dealt with is feeling frustrated or angry — feelings that can linger and affect the next interaction — all that is important is the win.

Ames says that middle levels of assertiveness tend to be associated with more effective leadership:

“We find what is essentially an inverted U between the ratings of a person’s assertiveness and the ratings of their leadership: up to a certain point it’s positively associated, and then it goes back down.”

How do you make someone who is too assertive less so? And how do you make a meek person more assertive? Ames recognizes that you can’t change someone’s character. But with the right kind of coaching, you can alter the person’s behavior.

Early in my career, I was assertively-challenged, if you will. But that gradually changed the more time I spent in the working world. I saw that assertiveness is not anger, and that there are just times you need to push your case.

I’m interested to see where TechRepublic members fall on the assertiveness spectrum. Take this poll and let’s see.