Hirschi and Gottfredson have made three important contributions: a focus on the entire life cycle rather than on the transition between adolescence and adulthood, certain observations regarding how explanatory factors relate to age and crime, and a new interpretation of the topic of early age onset of delinquency. However, their argument that cross-sectional research is as useful as longitudinal research overlooks some of the unique contributions of longitudinal data. Their arguments regarding age distributions of offending for different offenses or for social groups with different life circumstances are also flawed in several respects, as are their discussions of the meanings of data from different countries. Finally, their objections to the contributions of both strain theory and control theory to the understanding of crime and age patterns are either illogical or untrue. Familiar sociological concepts can explain much of the variation in the age distribution of crime, although further research is needed. Eighty-five references are listed.