Why is it that we respond differently to different people?What to do when we encounter inharmonious people?

Answer 1

On 1:

We each are unique. So is everyone else. That means, no interaction between two people is the same.
My interaction with you would be different than the interaction with my colleagues, or my girlfriend, or my neighbor.
Also, the setting determines a lot of how people respond.
At a party, you act different than at work, or at home.

On 2:

That depends entirely on your character. If you can handle the disharmony, you just act yourself.
If you can`t, then you either move away from these people, or you might confront them in some way - thereby creating hostility.
Personally, i tend to move away from them, but then i dislike confrontations.

Answer 2

1. b/c they will repond to our response in different ways.

2. walk away or try to adapt.