If you're the first person and you want to have some fun, push the button and when the door closes, go to the back left corner, face the wall and don't move. When the door opens, consider it a lesson in human psychology. By nature, people are impatient. They hate waiting. However, leeriness towards others trumps any impatience in a situation. People are naturally scared of other people. Even people who love everyone hate everyone in an elevator. So if person #1 gives person #2 any reason to be unsure about entering the elevator, person #2 will wait. People are also prisoners to normalcy. My hypothesis is that at least seven of 10 people would not enter an the elevator if someone is facing the wall. It disrupts the normalcy.
I sense a science project.