Deviant behaviour is generally defined as that which disregards or violates prevailing cultural norms. Those norms may be formal, as codified in our laws; or informal, as typified by what is considered polite and rude. Behaviour outside the norms can provoke in others feelings of excitement, disgust, hostility or desire for punishment. According to noted Columbia University sociologist Robert K. Merton, deviant behaviour generally falls into one of five different categories.
Conformity is the category that Merton reserves for those who generally do not engage in deviant behaviour. This is the section for those that conform to and accept cultural and social norms. Society dictates certain goals depending on class and social status, and an individual in the conformist category accepts those goals and the legitimate means of obtaining them.
Innovation is a slight warping of the conformist's views. Goals such as wealth and power are accepted, but the means of attaining these goals is deviant from social norms. An example would be a stockbroker who accepts that society has dictated wealth as a measure of success, but rejects the social stigma against illegitimate practices like insider trading to obtain this goal.
Ritualistic deviance is the opposite of innovative deviance. Instead of accepting the goals and rejecting the means, the ritualistic deviant rejects the goal but accepts the means. This is often the case when a certain behaviour is part of a routine, such as going to work every day even if you disagree with or outright reject the goals of your employer.
Retreatism is a combination of both innovative and ritualistic deviance. A retreatist deviant rejects both the goals of society and the legitimate means of obtaining these goals. Transients, drug addicts, vagrants or the habitually unemployed are examples of retreatists. As Merton maintains that deviance involves a conscious choice, this refers to an individual who remains in their circumstances by their own free will instead of by force.
In the rebellion category we have revolutionaries, terrorists and certain gangs. These individuals reject both the cultural means of society and the venues for obtaining them, but unlike the retreatist they pursue alternatives and seek to replace existing cultural norms with those in the counter culture. Merton considered the rebellion category to be special, and placed it separately under a "new means, new goals" category.