This is a follow-up to When to Pull the Cord.
As social as people like to think of the human race, we also like our space. Aside from public bathrooms, the bus is one place where this is very evident.
What happens when you get on a bus and there are plenty of seats free? You sit where you want. What do you do when there are few seats free? You sit wherever you can. More often than not, unless they are getting on the bus with a friend, most people will put a seat or two between themselves and the next person, creating a buffer, personal space (even with a friend, a lot of people make a buffer). Only when there isn’t enough space will people usually sit immediately next to someone else.
The question then becomes, what happens when some people get off and seats free up? Do you get up and go get your own seat or do you stay next to the person you sat next to earlier? What would the person you’re sitting next to think if you do? If you don’t?
If you move, the person may be happy to get their own space again. Or the may feel insulted that you felt you needed to move, perhaps because you think they smell or something.
If you don’t move, they may be upset that they are still being crowded when there is space available. Or maybe they are relieved that you don’t find them offensive, and perhaps even that other people will think that there must be something appealing about them to keep you sitting next to them when there are now free seats.
No matter what you choose, there will be some people who will view it as good, and some people who will view it as bad (and some people who will view it in ways that normal minds cannot even conceive of). In the end it more or less balances out, so there is no mathematical solution, and you are better off just doing whatever you prefer if the person does not give you an indication of their preference.