Since the 1930's, most criminological theorists have taken a social approach to understanding crime. However, recent critics of this approach have proposed using biological as well as social factors. For example, Herrnstein and Wilson have proposed developing prevention programs targeted at youths who show a proclivity towards criminal behavior. However, biologically oriented explanations of criminal behavior are full of both conceptual and empirical difficulties. In addition, offender characteristics are only one part of sentencing, because harm to the victim and other factors must also be taken into account. Finally, the application of biological perspectives on human behavior to public policy decisions is ethically problematic in a democratic society. Thus, public policy regarding sentencing and crime should focus on available social choices than on implementing a new biology that is conceptually and empirically flawed. 51 reference notes. For a response to this paper, see NCJ 112225.