I had this conversation at work with someone over lines at Disney. People are sheep and play follow the leader. They see someone stand in line, they'll get inline. Ever drive thru the MK toll plaza when its busy? The majority of people will stay to the right and the left is usually very open. Same thing on the ships. One or 2 families get in line, however mistaken they are, (because they are conditioned) and every one else follows. Ive seen it I don't know how many times in different venues.