Addiction, Genetics and Criminal Responsibility

43 Pages Posted: 9 Oct 2006

See all articles by Stephen Morse

Stephen Morse

University of Pennsylvania Carey Law School


This paper has two simple underlying theses. The first is that it is impossible to understand the relation of any variable to criminal responsibility without having in place an account of criminal responsibility. Otherwise, one simply begs questions. The second is that discovery of genetic or of any other physical or psychosocial cause of action raises no new issues concerning responsibility, and discovery of such causes does not per se create an excusing or mitigating condition for criminal conduct or any other type of behavior.

The paper begins with a brief description of the phenomenology of addiction, describing generally what we know about the behavioral aspects of addiction in addition to the basic criteria of craving, seeking and using. It then addresses the contrast between the legal and scientific images of behavior, using the disease concept of addiction as a prime example of the contrast. The paper next offers a general model of criminal responsibility to guide the analysis of responsibility for addiction-related criminal behavior. It suggests that the essential criteria are behavioral, broadly understood to refer to actions and mental states. The next part deals with persistent confusions about responsibility. The paper then describes those aspects of addiction, if any, for which persons might be held morally or legally responsible. It concludes that only actions related to addiction are appropriate objects of legal responsibility ascription. Next, it addresses the causal role genetics plays in explaining addiction. This discussion is deferred until this point because, as earlier parts explain, no particular causal explanation of any behavior, including biological explanation, entails necessary legal consequences.

The following part addresses individual and social responsibility for the addiction-related actions. It begins by considering in detail the meaning of those features of addiction - subjective craving and compulsion - that seem the most likely predicates for excuse or mitigation. It argues that understanding the biological roots of craving does not yet yield valid information concerning the strength of craving and seemingly compulsive behavior. This part next addresses the two leading theoretical and legal candidates for an excusing condition, internal coercion and lack of the capacity for rationality. It concludes that most addicts should be responsible for most criminal behavior motivated by addiction, but that addiction can in some cases affect the agent's ability to grasp and be guided by reason. The last section of this part considers whether society is responsible for addiction-related actions. I conclude that even if most addicts should be held responsible for addiction-related behavior, sensible social policy can do much to reduce both the prevalence of addiction and concomitant criminal behavior. The final part of the paper discusses three legal proposals for reducing the costs associated with addictions and for treating addicts fairly.

Suggested Citation

Morse, Stephen J., Addiction, Genetics and Criminal Responsibility. Law and Contemporary Problems, Vol. 69, p. 165, 2006, Available at SSRN:

Stephen J. Morse (Contact Author)

University of Pennsylvania Carey Law School ( email )

3501 Sansom Street
Philadelphia, PA 19104
United States

Do you have negative results from your research you’d like to share?

Paper statistics

Abstract Views
PlumX Metrics