I think that it only stands to reason those you associate with on a regular basis will determine a lot about your choices. Whether it be food or exercise, people tend to go with the group they are comfortable with and that is usually friends and family. Certainly, you are your own person and could vary, but realistically many of us, me included at times, cave to what is going on around us. If pizza is being ordered, we are in and if the walk is being skipped by everyone else, then we take the day off as well. It is interesting, but really not groundbreaking research on their part.