Why is it that one person's anger is viewed as qualities of leadership

[Wapsie B]

and with someone else that trait is looked on as being irrational?

A problem I have is that on the one hand I can look like this stone cold person to some. But get me in a negotiation or a situation where I’m scrutinized and I fold up like an omlet.

The last supervisor I had knew exactly how to push all my buttons and manipulate me with guilt. I allowed myself to be put through 3 interviews and then to be browbeat to the point where I was grateful to be given a job. At that point I was a pushover.Salary negotiations were a non-issue for the hiring director as I took their lowball offer. I cost myself a lot of money in that ordeal along with a mountain of self respect.

The thing is that the times I do try to stand up for myself I’m accused of being irrational and a tyrant, that I’ll get a reputation for being a hothead. So why is one person’s assertiveness a demonstration of leadership qualities but when I do it it’s looked on as being emotionally unstable?