In 1995, the Supreme Court of Georgia heard a lawyer make a novel argument. He had read a study describing violent behavior shared by several generations of men in a Dutch family. Scientists had identified a mutated gene shared by all the violent men, and that’s what got the lawyer’s brain ticking.
The accused, argued the lawyer, might carry a gene — like the men in the Dutch family — that predisposed him to violence. (The lawyer’s client was on trial for murder.) Therefore, went the argument, the accused did not have free will, was innocent of the murder and should be acquitted.
The defense, an attempt at legal trickery remarkable even for a lawyer, failed. However, scientific discoveries, particularly advances in neuroscience, are nevertheless having profound consequences for legal procedure.
For example, the insanity plea in the United States currently requires that the accused does not know, because of mental illness, that he did wrong.
The insanity plea derives from the M’Naghten rule, a case from English law. In 1843, a man named Daniel M’Naghten attempted to assassinate the British prime minister; at his trial, he was found to be insane and the trial was abandoned. From that point on, lawyers saw the power of mounting an insanity defense, and many such claims were made.
“By the early 1980s, half the USA and most federal courts were using some sort of insanity test that incorporated elements of loss of volition,” said Robert Sapolsky of the Department of Neurology and Neurological Sciences at Stanford University. “This trend abruptly reversed when the potential assassin of Ronald Reagan, John Hinckley, was acquitted.”
The acquittal caused a public outcry, and U.S. courts were put under intense pressure to make it more difficult to make a plea of insanity and to restrict claims of impaired volition. Now Sapolsky is calling for a serious reassessment of the law.
Here is an interesting one I just came across on Wired.com. The title of this article is Are we puppets or free agents? and while the article itself is focussed on the question of whether so-called insane people have a choice when it comes to committing criminal acts, it does touch on a broader question being whether we have free will or whether we are bound by biology or circumstance? I have only quoted a portion of the article (you can view the full article here):