I've copied this in its entirety from the latest issue of
PNAS July 13, 2010 vol. 107no. 28 E114
Has biology disproved free will and moral responsibility?
- Henrik Anckarsäter1
- Department of Forensic Psychiatry, the Sahlgrenska Academy, University of Gothenburg, 422 50 Hisings Backa, Sweden
In his Inaugural Article entitled “The Lucretian swerve: The biological basis of human behavior and the criminal justice system,” Andrew Cashmore suggests that penal systems based on moral responsibility have to be reformed because science has refuted the notion of free will (
1). Brain imaging and other functional neuroscience methods have indeed been used not only to map neuronal covariates to behaviors but also to detect action potentials for simple movements hundreds of milliseconds before the conscious decision to act (
2). Genetic factors have been shown to explain at least one half of the interindividual differences in the liability for criminality in different types of epidemiological study designs (e.g., adoption, twins, and family) (
3), whereas molecular genetic studies indicate that no single genetic mechanism accounts for more than a couple of percentages of the variance in crime-related phenotypes (i.e., that the existence of one or a few “crime genes” can be discarded) (
4). These facts are very useful. We now know that the chances to refrain from criminality are unfairly distributed and partly under the influence of constitutional susceptibility factors. Some of these, such as childhood hyperactivity and lead poisoning, have been identified in population-based epidemiological or clinical studies and may guide preventive efforts. Hopefully, this is just the beginning of a scientific endeavor to establish explanatory models and evidence-based, acceptable treatment for people at increased risk of aggressive antisocial behavior. Does it, however, have a bearing on moral responsibility and penal law?
The answer is given by considering the preconditions of science. Covariation does not equal causation. One half of the population variance does not equal one half the crimes or one half of all crimes. The proportion of variance that remains after subtracting genetic effects is by default ascribed to environmental effects, but these cannot be distinguished from randomness or a potential influence of free (i.e., noncaused) volition. As long as the total variance in criminal behaviors has not been explained or a sufficient cause of a crime demonstrated experimentally, all that modern science has shown is that there are constraints to human freedom, which was already recognized in ancient writings.
Nor is Dr Cashmore's stance new. It is rather pre-World War II modernistic, the era when Sweden's first professor of forensic psychiatry, Olof Kinberg, gained the attention not only of a wide international readership in criminology but of Swedish legislators, who eventually dismissed the notion of accountability (referred to by Kinberg as “transcendental rubbish”) and introduced psychiatric treatment as a form of sanction (
5). After legal, societal, and ethical drawbacks, legislators still try in vain to disentangle the resulting confusion of science, medicine, and justice, the roots of which are the same as those behind the notorious sterilization campaigns. To the extent that data are interpreted rigorously by the hypotheses they test, science holds unique promise as provider of knowledge about the aspects of the human that may be studied by quantification and models of causation. If abused to address issues that may not be answered by its methods, science becomes scientism, a mere candidate of a worldview.
