Theories that focus on the individual include psychological and biological explanations. Biological theories have focused on body type, genetic factors, studies of twins to differentiate between genetic and social factors, and studies of chromosome variations. This literature suggests that criminality is genetically transmitted through the family. Psychological theories also focus on the individual. They consider internal characteristics influencing criminal behavior and have proposed that criminal propensity is a function of psychological trauma and maladjustment early in the family experience. A second category of theories focus on social structure and social process and their promotion of criminal behavior. Learning theory and subcultural theory have generated the propositions that criminality is transmitted through the family socialization process and is encouraged by families entrenched in criminal subcultures. Theories focusing on conflicts in cultural values propose that families as well as individuals are affected by cultural pressures to commit crime. The conflict theory suggests a parallel proposition: that families as well as individuals are affected by social inequality and resulting structural pressures to commit crime. Literature focusing on social stress has suggested another proposition: families under stress generate crime. The third broad theme among criminological theories is the societal reaction focus. This approach considers how societal mechanisms created to control crime may be partially responsible for causing it. This analysis results in the proposition that crime is a product of criminal typescripting within, by, and against families. These propositions are not established facts. Instead, they represent guides to thinking about the issues and serve as hypotheses. Fifty-three references are listed.