Generally speaking, do people who are or bitches as the case may be put on a guise in the social?

group as being friendly, nice people? I mean when other people are present and where there is a reputation at stake they are funny and friendly and chatty or when they are around a superior like a boss, lecturer or something but in actuality they are really an ? They just know how to turn on the charm when they need to. Is that why these sorts get ahead?