A norm can be described in many ways. The descriptive definition of norms is what people in general do. The prescriptive definition is what people should do and the proscriptive definition is what people should not do. Many norms are useful for individuals and groups. They are the basis of common meanings for signs and symbols in our society and, therefore are the foundation of communication. They are also the basis for the coordinated behaviors we must perform as a society – for example time, driving regulations, and common definitions of weights and measures. As well, they are the foundation of social ethics and the common conceptions of what is right and wrong, and in the development of laws.
Social Norms are the expectations about how people should act. Usually social norms are created by having the same sort of certain behaviors among social group members. Also, there are usually negative consequences when someone violates a social norm.
Norms do serve a purpose, as they allow people to expect the events that will occur in a particular setting. This allows people to prepare themselves for being in that situation. Uncertainty is a big source of psychological stress. Norms allow us to reduce the uncertainty that we might otherwise feel in a situation, or leading up to a situation if we knew nothing about how that situation would unfold.
However, norms can be self-perpetuating, as once they are established they will often continue, even when those who established them have long since left the situation. For example, medical physician training procedures, and other rites of passage.
The norm of obedience dictates that people in positions of legitimate authority should be obeyed, where legitimate is a pre-defined group, and some positions (or people) are endowed with authority, and some are not. Authority derives from the status of a particular person. Obedience is behavior change that is produced by the commands of authority. Positions of legitimate authority include: parents, teachers (professors), police officers, politicians, work supervisors, etc. People have been taught from birth to obey appropriate authority.
Appearances can affect the appearance of legitimate authority, or create it entirely. That is, people who look the part of the authority figure are likely to be treated as if they are the authority figure, even if they are not. Appearances may be created by the way the person is dressed (doctors in white lab coats with stethoscopes, and thieves dressed like the meter reader), by their title (Dr. So-and-so, Reverend Blah-blah), by their office (the more impressive the office the more likely the person has some real weight), or some other effect.
Signs are another way to create the atmosphere of authority. For example, it has been found that people will simply obey a sign because of its presence, even if there is no basis or reason for it to be there.