How we change what others think, feel, believe and do
We maintain two kinds of face:
Both of these may be threatened when someone makes a request of us.
This causes a dilemma, as if I ask in a pleasant way, positive face is satisfied but negative face may lead them to think they can take advantage of us. The reverse is also true, as defensive talk will threaten the positive face.
Conformance to the social rules of politeness is treading a central and safe path which neither threatens nor signals that you may be threatened.
Politeness means acting to help save face for others.
When I am with my boss, I show positive face. When I am with the new guy (who seems pretty incompetent) I show negative face.
Build trust by being polite. Use negative face with out-group people or those who would dissuade the other person.
Just because a person is polite it does not mean they have good intentions towards you.