I spend a lot of my time coaching managers, trying to help them grow and become great managers. A good portion of my time is spent helping managers understand feedback they have received from direct reports, peers and their managers. Inevitably, there comes a time where, based on the feedback, I will say to a manager, "Well Pete, it seems like some of your employees wish you were a little more assertive at times".
(I know, I should let them figure this out on there own. It's just that, typically, people tend to have a hard time acknowledging their weaknesses, so I have to bring it up)
To which they will, inevitably, reply "That's just not me!"
Now, it's pretty clear that they are lacking in assertiveness, otherwise they would not have received the feedback stating the need for more assertive behaviors.
What I am wondering is, what are some of the methods you have used to help managers overcome there most noticeable weaknesses? Particularly when they state that it is just not they way they behave. What has worked for you?

I am going to take a different route at answering this question; my initial thought is 'Are they in the right position?' As we all know being a Manager requires MANY skills, behaviors, attitudes, and values and obviously every Manager is not immediately skilled at all of these requirements. We all at one time or another needed coaching, feedback, and training to be the best Manager they CAN be (like it sounds you are doing here).

However, when someone responds to coaching by saying "That is just not me" I have to wonder if that role is for them or more importantly if they are fit for that role. If it is not in that person's 'natural ability' to be a Manager and do the things necessary to lead a team, the team will see right through it will receive no respect from their employees and peers.

If they are responsive to coaching and feedback, but just do not believe that they are (for example) being assertive enough, I can help with some methods. But, that does not sound like the issue here - please let me know if I am wrong.

Mark-

We can not assume managers have all of the necessary skills to manage others, nor will they ever acquire all of them. As long as the acquire enough skills and display enough positive behaviors they should be fine managers. The question is about managers who, for arguments sake, are good managers and whose employees would like them to develop a skill or behavior that they (the employees) feel will help them be a better manager. How do you push them over their hesitancy, specifically when they feel that this new skill/behavior does not fit into their existing set of skills/behaviors? It's just not them, it's just not they way they work or behave.

Thanks for the clarification that 'they are good Managers' - I misunderstood you.
There are two books out there that I would recommend and may help. The first is 'First, Break all the Rules' by Marcus Buckingham which I believe is right on-task with the opportunity. He also wrote another one that followed named 'Now, Discover Your Strengths', however this talks more about focusing on your strengths than your weaknesses so the Manager could get the wrong idea from this one.

In addition, I might suggest a mentorship with another Manager (or better yet a VP equivalent) who's strengths are this Manager's "opportunity" to show the value it brings to the employees and business.

Depending on the Manager's personality and learning style, I would focus my efforts on what will convince him that this is the right thing to do - for me as an example, I would:
(1) Want to see the results as a direct communication from my Employees that this what they want (i.e. possibly via a Survey every 3-6 months so you can track progress througout the learning period)
(2) I would want to know WHY they/whomever wants this
(3) Understand the BENEFIT OF DOING IT to make sure my efforts will pay of doing this; not only WIIFM but what is in it for my Employees and the business

What type of person are they? Have they taken a personality assessment (i.e. DISC, PIAV, MBTI, Birkman, etc.) - if so, what were the results? This will help determine the best method and how to best communicate with them.

Dvsnhd99,

You might consider providing this manager with specific examples of how he/she has shown non-assertive behavior. Hopefully this information was given by the employees providing feedback on this manager, or you have observed it first-hand. Then, if you get acknowledgement from the manager, have the manager think through how he/she could have demonstrated assertive behavior instead. You might have to provide a few examples for the manager. Maybe role play a few scenarios.

Unless the employees can provide you with specific examples of the non-assertive behavior of the manager, I would not put too much into it. They could be wrong. (You should at least give the manager the benefit of the doubt when he says, "That's just not me." - unless you have observed the non-assertive behavior yourself, or have specific examples. (Please do NOT rely on some personality assessment!) To try to "correct" behavior that is fine to begin with can have disasterous consequences and ruin your credibility completely. Coaches need to be very aware of their own limitations, qualifications, and expertise - and honor them.

If this manager is truely not assertive enough to get things done and it continues to be a problem with the employees, Mark may be right in suggesting he/she shouldn't be a manager. Some people are so intent on pleasing everyone that they never do well in a management role. It just doesn't work.