As for altering the subjects to get what we are after, or staging, perhaps if the shot doesn't "appear" staged, then we have successfully achieved our goal.
Remember a motion picture (movie) is an entirely staged event, but that doesn't mean the emotion and magic between the people isn't real and doesn't necessarily affect us as spectators any differently than a real event. There were a lot of people crying during the movie Titanic. And some for the right reasons. Obviously some because they could never get those 2 hours and their money back.