How unwritten rules circumscribe our lives

On the train people sit face to face. Some people feel that it is an awkward situation. If you look forward, you will see the other passenger's face.That behavior will make the other passenger uncomfortable.  Otherwise, you have to pretend to look at the ground or out of the train window. I believe most people would take the second measure except young kids who will directly look at you with their innocent eyes.

However, this is not a rule you can find in the law book. No one is going to be in jail if he insists of doing this. It seems that there is a invisible angle floating over you head telling you that you'd better not do this. To be more specific, the unwritten rules play an important part in our lives. In many  occasions, the invisible angle over your head will instruct you.

Every time I go to the library I am interested about how the student choose their seats. A guy picks up a book which he wants to read and he looks around to find a desk. If there is another empty table, he would never choose a nearer desk where there is already a person. Even though the desk could accommodate 4 or 6 people.  If there is no empty desk at all, he definitely will choose to sit diagonally but not face to face. This occasion occurs to everyone. It seems that there is a very clear principle(actually there isn't) that when people face with the choice of where to sit. The principle is very clear—stay away from the other guy as far as possible.

The invisible angle will come out to remind you when you see the old man get on the bus. After a long day's work, you are tired and exhausted. However, the invisible angle just doesn't want to make you feel well if you let the old stand by you. Here comes the same question, you won't be suited if you don't offer your seats. Why does everybody still invite the old to be seated?

The reason is that we all share the same values.Most people in the society agree that we should follow some rules. Some of them are incorporated into legislation while others are not, but they still affect our lives a lot. Sometimes they even are stronger than the written ones. We can't pretend they do not exist.