I don’t have the source for the studies, but generally speaking, it’s true that you will live at a level somewhere around the average of your relationships.
For example, if you take your 5 closest relationships and average their annual income, the chances are likely that your annual income will be somewhere around that average. Now obviously, there are other factors that come into play, yet this generally turns out to be true.
We are social creatures — relationships and connections affect us in significant ways. Consciously and unconsciously.