I think the biggest (and perhaps most difficult) shift a person has to make when s/he makes a move to leadership is the Relationship Shift. (Try saying that three times fast!).
In working as individuals we often develop relationships with our co-workers, many of whom may actually become our friends. We tend to pick and choose the people with whom we become close. We become involved in their lives. They become involved in ours. And the balance of power between us tends to remain reasonably level.
Promotion to a leadership role changes all that. Whether you are promoted within your current work area or move to another area or even another job, know this:
Promotion to a leadership role demands the establishment of a professional distance between you and those who work under your supervision.
This does not mean that you must isolate yourself from the people who work with you, far from it. It does mean though that the relationships you develop must transcend your personal feelings about the people in your work group and expand to include an impartiality that allows you to make appropriate decisions and get the work done.
This shift in relationships is not a one-way street either. With promotion to a leadership role comes a change in the balance of power. People who were once peers become, (organizationally speaking), subordinates and that means that you will have some influence over areas of their working life that you previously did not. They will be looking for evidence that they can trust you with that. And they will expect you to be fair about it. So, you may not be invited to lunch as you once were. And if you are, you should consider the wisdom of accepting.
The up-side to this (and there’s always an up-side) is that as a boss, you will have opportunities to build new relationships with not only those who work for you but with a new set of peers. One of the crucial roles of a leader is to build relationships across a variety of lines of work. This allows for easier communication, collaboration between and among stakeholders and an opportunity to learn new things from a variety of perspectives. And that’s a good thing.
So while you may initially feel the loss of your previous working relationships, there is a bigger world out there for you to play in. Enjoy it!!
Here’s Something to Read: An article about Professional Distance.
Something to laugh at: Here’s a clip from Fawlty Towers called “How to Manage Your Staff”, a classic example of how NOT to!
Something to Think About: Since becoming a leader, how have your relationships changed? What did you have to get used to? What surprised you?
You're Not the Boss of Me 
Great points. When getting promoted I have heard people say – yeah but I am still the same person. We may not change who we are, but you are right on that we must change how we relate. I also think we need to be awake to the impact a promotion may have on the people who were our peers yesterday. Try as they might not everyone will be happy for you.
A change in context of your relationships changes everything and as you point out a promotion requires that we change. At some point in our development as leaders though we realize that if we truly want to lead then we must stop relating to people from the comfort zone of our likes and dislikes and start relating from what we and they are committed to. So it occurs to me that another upside here is that it gives us an opportunity to practice/develop this important skill.
Absolutely! Learning to rise a few feet more off the ground to look at a bigger picture has its challenges, not the least of which is developing the skill of forming relationships with purpose rather than at random. So yes, opportunities to practice that is indeed part of the upside of making the move to leadership.
And I love that line, “but I’m still the same person”.
As you say, so many people seem to say it but they always find out that things really aren’t that simple.
Thanks for the great comments Susan:))