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.