Suppose you look at it from an individual's point of view, isn’t there just one thing that is going on - a survival mechanism? This means wearing different masks for different occasions. At the risk of over-simplification, one can think of the following masks- one to show subservience to the employer, one to show docility to spouse/parents, one for friends to brag about your scoring with girls/boys, etc etc. It is all masks, masks, and masks. Would you call this “multiple personality”?