Three categories of explanations of criminal behavior have dominated criminology at different historical periods: limited-factor reductionism (a focus on one aspect of the criminal as an explanation of criminal behavior), multiple-factor approaches (identification of a variety of factors related to criminal behavior), and systemic reductionism (criminal behavior explained in terms of a particular system of knowledge, e.g., sociology). All of these approaches fail to be sufficiently comprehensive to encompass the multiplicity of factors contributing to criminal behavior. Any integrated theory of criminal behavior must be interdisciplinary. Such an integrated theory would cover the following knowledge domains: cultural, social, personality, and biophysical. Such an approach requires moving from the current focus on sociological explanations of criminal behavior to an increased emphasis on psychological and biophysical factors. 1 figure.