The discussion emphasizes that the nature of the information gathered on the subject depends largely on the wording of the questions, that studies of criminal careers tend to be descriptive rather than explanatory, and that the descriptions are usually based on captured criminals only. It also notes the problems involved in measuring criminal behavior, particularly the critical role of defining the events or characteristics to be tallied. The discussions of causality focus on the structure and stability of human personalities, the ways in which learning is believed to occur, types of external circumstances that influence behavior, and the statistical and other criteria for assessing causality. Illustrations, footnotes, name index, subject index, and more than 700 references.