Deviant behavior is defined as any behavior that goes against the social norms. As norms change in time, so does the description of deviant behavior. Doctors have developed several theories about the causes of deviant behavior.
The structural strain theory was developed by Robert K. Merton and states that deviant behavior is caused by a gap between cultural goals and the means people have to achieve those goals. People set personal and professional goals for themselves in regards to education, work, family and other areas. Society is supposed to provide the means to help people achieve those goals. When adequate social systems are in place for people to reach their goals, they do not need to resort to deviant behavior. However, when the support systems do not exist, people resort to deviant behavior as a means to get what they want.
The social control theory believes that people are more prone to deviant behavior when they fail to form appropriate social bonds. People with stronger bonds seek acceptance from those around them and, therefore, conform to the expectations of society. Those with weak bonds are often concerned about their own wants and desires and achieve them at the expense of others. The labeling theory says that no behavior is inherently deviant. Instead, society labels those behaviors they do not like as deviant, with the dominant groups in society having most of the control over what is considered acceptable behavior.