"Crime exists only to the extent to which behavior is legally defined as criminal by the larger society and culture. In some contexts (e.g., war, executions in correctional contexts) it is not a crime to kill another human being. In some states (e.g., Nevada) it is not a crime to engage is prostitution. Until 2003 engaging in a homosexual act was a crime in many states in the United States, and it is currently illegal in some places around the world. (1) “Crime is not an entity in fact but an entity in law” (Radzinowicz, 1966, p. 22) and “technically speaking, there is no ‘crime’ without ‘criminal law’” (Shelden, 2002, p.23). “Criminal behavior is a special category of behavior that has been defined through socio-cultural-legal-political-economic processes as outside of the bounds of the law.” This is important in reviewing criminal behavior research because theoretical concepts central to understanding the mechanisms of criminal behavior such as “antisocial behavior”, “aggression”, “psychopathy”, or “deviance” are sometimes confounded with criminality in the research literature and popular discourse. For example studies on aggression are often conducted in laboratory settings with animals or humans who are engaged in some laboratory task. “Can research on aggression in rats be applied to human crime and violence? Are the processes that produce antisocial behavior, such as lying or cheating on a spouse, the same processes as are involved in violating the law? Can theories explaining how people develop deviant identities also explain how people develop criminal identities? Much of the current knowledge base on crime and criminal behavior draws from research focusing on these other concepts."