All human societies develop expectations for behavior that become part of the shared culture. These implicit social norms are communicated to us at a very early age, and exert a powerful influence on our behavior into adulthood. Our culture is ruled by these social norms. "Social norms are the implicit or explicit rules a group has for the acceptable behaviors, values, and beliefs of its members (Deutsch & Gerard, 1955; Kelley, 1955; Miller & Prentice, 1996, 263)." In many situations, people's perception of these norms will greatly influence their behavior. Implicit social norms are not openly stated, but you find them out when you disobey. These implicit rules are rules we conform to as a society, and generally these rules make living together more comfortable. Social norms are important because they define the nature of a group, clarify relationships among members, and express values. They are also important because they create cohesion within the society, and members of that society are very aware when such norms are violated. Social norms are often strictly enforced and offenders are often disliked for their conduct. Also, some norms are more strictly held to in certain situations than in others. For example, it is a social norm that people should be decently covered in public, but a woman wearing a swimsuit and shorts into Burger King is less likely to be ostracized than a woman wearing the same outfit in a Church.
Another important part of social norms is called the normative social influence. This is "the influence of other people that leads us to conform in order to be liked and accepted by them; this type of conformity results in public compliance with the group's beliefs and behaviors, but not necessarily with private acceptance of the group's beliefs and behaviors (Aronson, Wilson, Akert 2002, 264)." For example, some people behave in ways just to gain approval from others, even if they don't necessarily believe in what they are doing.