Anywhere there is a lot of people gathered together it is imperative that there is a necessity for law enforcement or some kind of group of people to ensure safety and smooth functioning of the event. Growing up in India I would see how people waiting in the Bus stop would forget all civility and rush toward the door when the bus arrived. They would not think even for a moment about forming a line, the priority was to get in first and take their place. The same phenomenon I noticed in America when a sale takes place in any of the super stores. For example during the Black Friday sale people go to the extent of pepper spraying competing shoppers to get what they want. My own experience recently was that even though I was first in line for petrol before I could reverse the car and get it into place for fueling up, another person (middle aged white man) pulled into the bay and started fueling up his car. I had to wait and fuel up after he finished because of his lack of civility.
Recently I came upon a similar scene in nature. A group of water fowl were on the shore of lake at Bonham State Park. They were feeding on insects on the ground in a random group. As I approached them to get a closer picture they sensed my presence and started back towards the waters of the lake. There was enough space for the birds to go in a parallel formation and get into the water, but the birds chose to follow their leader and walked toward the lake in a single file. There was no one to enforce discipline, no limitation of space, nothing but these birds naturally followed the discipline and displayed civility that humans often don't show.
We humans are after all more animal than we think we are, and definitely being well groomed and wearing sharp clothes doesn't make us any better.