Medical Difference of opinion disorder?

[waht]

When two individuals have a difference of opinion, especially about politics or religion, then they get furious, aggressive and become your worst enemy.

On the other hand, if you know someone or even a stranger that shares similar view then you, then automatically you get the feeling he is your best friend for the time being.

Not sure if this is a case of narcism, as posted in the other thread, but I have noticed a lot of ordinary people displaying these traits.

I'm wondering if this has a correct name and also what are the casues of this?

 

[Evo]

When two individuals have a difference of opinion, especially about politics or religion, then they get furious, aggressive and become your worst enemy.
On the other hand, if you know someone or even a stranger that shares similar view then you, then automatically you get the feeling he is your best friend for the time being.
Not sure if this is a case of narcism, as posted in the other thread, but I have noticed a lot of ordinary people displaying these traits.
I'm wondering if this has a correct name and also what are the casues of this?

Birds of a feather flock together.

People normally tend to seek out the company of those that think like they do. This is normal behavior.

Narcissism is the love of ones own self.