In June, the Supreme Court upheld a narrow Arizona test for legal insanity, which asked simply whether mental disorder prevented the defendant from knowing right from wrong. Last week, a Texas jury used a similarly narrow test to decide that Andrea Yates was legally insane when she drowned her five children in a bathtub, allegedly to save them from being tormented forever in hell. Many scientists and legal scholars have complained that tests like these, used by the law to determine criminal responsibility, are unscientific. Given recent advances in our understanding of human behavior and of the brain, these critics argue, the legal test for insanity is a quaint relic of a bygone era, says Morris B. Hoffman and Stephen J. Morse in a New York Times op-ed.
These criticisms misunderstand the nature of criminal responsibility, which is moral, not scientific. On the other hand, legislation that has eliminated or unduly constrained the insanity defense, often in response to unpopular verdicts of not guilty by reason of insanity, is likewise off the mark. Between these two attacks, the concept of the morally responsible individual seems to be disappearing. Hoffman and Morse argue that the legal definition of insanity appears once again to be in for an adjustment.