The functionalist theory of crime is used by sociologists. The  functionalist theory is a reaction on the psychoanalytical theory of delinquency. The main functionalist representative was Robert Merton. The part of functionalist theory, which explains criminality starts with an idea that all people are born benign (benevolent), while deviant impulsive behavior is induced socially. The theory is sometimes called "consensus theory," because it doesn't look on the society from a conflict perspective, but from a perspective of social harmony. Functionalists have described American society as the society, which has its cultural goals and institutionalized ways for achievements of those goals. Understandably, the main goal is the money (cash, bucks, fed notes, greens). Financial success is the major goal, and the ways to achieve it are the education and employment. Education and employment are the guarantee for achievement of financial success. Functionalist used Durkheim's strain theory to explain certain periods of societal dysfunctionality. During the period of social anomie, new inventions are made and deviants are focused on the achievement of goals and don't care much about potential consequences of theirs actions. Members of lower and middle socio-economic status wish to financially succeed, but don't have the access to legitimate and institutionalized means or resources. Because the goals are not achievable, some of them turn to illegal ways to reach a prosperity. Functionalist concluded that American society doesn't emphasize the importance to respect social norms.

Different reactions are possible on social anomie such as:

1. innovation

2. social conformism

3. ritualism

4. retraction and

5. rebellion .

 Functionalist theory critics state that functionalist offer the incomplete explanation on how the distribution of goals and resources is made. They also think that functionalist hadn't fully explained the connection between social anomie and delinquent behavior. Critics state that it isn't clear which of the social reactions includes delinquency.

Conflict theories are opposite to functionalist theories. Most common views of academics are that supporters of conflict theories are extreme leftist and communists. The both theories are a form of idealism.