Behavioral Economics, Neurophysiology, Addiction and the Law

Abstract

Has science anything to tell us about responsibility? Addiction is a particularly interesting test case. Two fields of science, behavioral economics and neurophysiology have lately given us a great deal of information about addiction, much of which may be useful to the law. When it comes to addiction, unfortunately, the two fields seem to point in opposite directions.

Economics has provided us with models of addictive behavior based upon the supposition that addiction is the result of choice, a development that appears to support the conclusion that addictive behavior is not the product of "non-volitional forces." If addictive behavior can be fully accounted for in terms of the addict's choices, and if there is no need to postulate the existence of forces overwhelming the addict's will, is there any reason not to hold the addict fully responsible for what he does?

Neurophysiology, on the other hand, has demonstrated that substance abuse causes significant changes in brain physiology, which appears to support the conclusion that addiction is a disease. If addiction corresponds to physical changes in the nervous system, then addiction is a disease, and addictive behavior is merely a symptom of the disease. We may be responsible for contracting a disease, but can we be held responsible for the symptoms once we have it?

Science does have a good many things to tell us about addiction, but so far whether or not the addict is responsible for what he does is not among them. The fact that choice theories - rational addiction, behavioral economics - can develop models in which addiction is the result of choice should not surprise us: Did anyone ever believe that addicts did not intend to do what they were doing? Did anyone ever believe that addicts did not choose to do what they did? The question has always been whether those choices were free, and whether the addict was fully in control of his choices. That is the question that the law must deal with, and in this paper I argue that choice theories have nothing to say to that question. Neurophysiology, on the other hand, has made remarkable strides in tracing down the effects of heavy drug use on the brain. But that behavior should effect brain changes is not by itself remarkable, and does not entail that behavior is not fully voluntary.

There are three possible conclusions. The first is that although science has yielded no results so far, we may hope for results in the future. The general nature of the arguments against drawing conclusions about responsibility from the existing literature makes that, if not entirely a vain hope, at least implausible. The second is that responsibility is simply one of the areas of human experience that is cut off from science; there must, therefore, be other ways of knowing what we do about addiction, control, and responsibility. And the third conclusion may be the most pessimistic of all, namely that responsibility itself is a confused notion, and that we should be skeptical about its role in the law.