coping with multiple selves....

Is it not evitable that a person although having a single body infact has multiple selves? It can take varied forms depending on where the person sees him/her in society and also very much upon the idiosyncrasies that one can be attached with. But if we are a mere aggregation of these bits and pieces, how can we get to the core? or can we? This leads us evidently to the question: who decides the choice of the selves at any point in time give any situation? Is this what we commonly refer to as character and what is it that prevents it from being volatile? if whatever we do can actually be seen as a stimuli-response system, are we actually nearing a point where our activities can be codified and with some effort even predicted? Sounds pretty grim to me..........