Criminology is the scientific approach to the study of criminal behavior and society's reaction to law violations and violators. It is essentially an interdisciplinary field; many of its practitioners were originally trained as sociologists, psychologists, economists, political scientists, historians, and natural scientists. Criminology has a rich history, with roots in the utilitarian philosophy of Beccaria, the biological positivism of Lombroso, the social theory of Durkheim, and the political philosophy of Marx. In the late 1960's, criminal justice programs were created to examine and improve the criminal justice system in the United States. Today, many criminologists work in criminal justice educational programs. Criminology and criminal justice are mutually dedicated to understanding the nature and control of criminal behavior. The study of deviant behavior also overlaps with criminology because many deviant acts are violations of criminal law. The criminological enterprise includes such sub-areas as criminal statistics, the sociology of law, theory construction, criminal behavior systems, penology, and victimology. Criminologists believe in one of three perspectives: the consensus view, the conflict view, or the interactionist view. The consensus view holds that crime is illegal behavior defined by existing criminal law. The conflict view states that crime is behavior defined so that economically powerful individuals can retain their control over society. The interactionist view portrays criminal behavior as a relativistic, constantly changing concept that reflects society's current moral values. Criminologists use various research methods to gather information that will shed light on criminal behavior. Each type of method, including surveys, longitudinal studies, record studies, experiments, and observations, focuses on a different aspect of research. 46 notes, 4 figures, and 6 photographs