Is it the Mercury sign that determines your self-tolerance and demeanor to others?

[Darling, Danger ®]

I know a Pisces Sun, Aries Mercury and she was so mean to me. She was intolerable, impatient and always making fun of me and others. Insults were her forte. But that's just her, I'm not saying all Aries Mercury people are like this. Just my theories. What would be the reason why some people are mean?

I try not to be mean because when I'm mean I'm repetitive about it and I learned the hard way that if you repeat something whether it's good or bad over and over again, they will actually start believing it, despite the fact if it's true or not. That's why I quit being mean because I actually convinced someone that they were something they're not. That's the reason why I'm not mean.

What in a chart would indicate why someone is so mean, threatening and insulting of others? Insecure signs perhaps?
Omfg, how repetitive can someone get? I'm so repetitive, lol, see? I'm repeating myself again. Wtf. I think it's like communication ocd.
Lol and for the self-tolerance, I meant as in to yourself duh. Like, if you're mean to yourself?
Fire signs are mean? Well, they are blunt.
Whisper, yeah I thought it was my Mercury in Libra opposing her Aries in Mercury too. I wonder why Virgo Mercuries do that, honestly I have no problem with it, I actually encourage my friends to point out my flaws so I could better myself, but I just wonder...if it's to be mean or to be helpful.
Alpha Me, it's definitely not the Mercury sign than. ( :

 

[Alpha Me]

I'm Aries mercury and not mean. These types of things just can't be generalized.

 

[Whisper *Misery Business*]

I think people have different opinions of "mean." You're a Libra, and Aries is you're opposite sign. Maybe that's why you perceive that person with the Aries Mercury that way.

For example, a person that thinks a person that picks at every flaw is mean, might think people with a Virgo mercury is mean.

Well, that's my theory.

Edit: Haha. My mercury is in Libra too. =)