This chapter focuses on the violation of societal norms and on reactions to norm violations. It is concerned with informal social control—the reactions of family, friends, and acquaintances to rule violations by individuals. The chapter indicates that often a person is labeled a slut, gay or lesbian, or an alcoholic based on indirect evidence. It considers first the nature of norms and then looks at several theories about the causes of deviant behavior. These include anomie theory, control theory, differential association theory, and routine activities theory. The chapter discusses white-collar crime, which is often committed by middle-class and upper-class persons. It suggests that crime rates are higher among lower-class persons because they are more likely to be arrested, prosecuted, and found guilty, even though the underlying rate of deviant activity may not vary as a function of social class.