An MS is, literally, More of the Same... assuming you are taking the next level of whatever you decided to major in with your BS electives etc.

I think you really need to evaluate your own personal "bent" regarding psychology vs sociology. For me, social services don't really work on the why with change, but the what with change.

Sociology is more of studying how people are and then working to engage them there. Psychology is more of finding where people are and helping them to move to where they wish to be.

I'm in a bit of a pain flare, so maybe on another day I will state this more clearly?