Does Brain Difference Affect Legal and Moral Responsibility?

An exploration of three cases that highlight the relationship between brain disorder, law-breaking, and norms relating to responsibility.
Does Brain Difference Affect Legal and Moral Responsibility?

By Bradley Segal, HMS3

In this neuroethics seminar, panelists discussed three actual cases and explored the extent to which neural variations affect legal and moral responsibility for criminal acts. Dr. Fiery Cushman, PhD, a neuroscientist who studies moral judgment, Amanda Pustilnik, J.D., a law professor and Dr. Judith Edersheim, M.D., J.D., a forensic psychiatrist, participated in the discussion.

In the first case, a middle-aged accountant developed a brain tumor while simultaneously hiding company checks in his drawer, apparently with no intent to steal the money. After the tumor was discovered and resected, his behavior returned to normal. He later told investigators he was ashamed by his actions at work, but lacked insight into why he mishandled the money.

Dr. Cushman observed that we generally hold individuals less culpable when their actions are involuntary. For example, in psychological experiments, subjects cast less blame on a person who spilled her drink because her arm jerked when a bee landed on her hand. Similarly, in this instance the mishandling of money was not deliberate and the lack of intent due to a tumor diminishes our intuitions about the accountant’s culpability. Yet Professor Pustilnik pointed out that pursuant to criminal liability statues, the individual in the first case probably could still be convicted. What would be the justification for punishing the accountant?

There are two major types of justification—retributive and utilitarian. Retributive theory is backward looking—asking questions such as: what has a person done; how blameworthy was he or she; how much punishment would “pay” the offender’s debt to society?  By contrast, utilitarian theories solely look forward, asking questions like: what good will a punishment accomplish; how much does it help society to punish; does punishment deter wrongs cost-effectively?

On the retributive view of punishment, the defendant is not blameworthy since the tumor overrode his decision-making. On a utilitarian view, once the tumor was resected, the offender was unlikely to commit another crime. Punishing him hence violates both common intuitions and moral principles as to why the person is not culpable. Nevertheless, Professor Pustilnik explained from a procedural perspective why this “morally-obvious” case might actually be a close call.

In the second case a male with an extensive psychiatric and neurological history murdered his abusive wife. He was caught in the act of murder, but does not remember committing the crime. One neuropsychiatrist diagnosed multiple disorders including dissociative identity disorder (multiple personalities); another suspected malingering.

Dr. Edersheim noted that unlike case one, the second scenario involves a murder. Criminal law requires that the state prove a criminal defendant had a mental state (mens rea) involving intent to harm the victim. If the defendant lacked the capacity to form such a mental state, he might be able to convince the jury to accept insanity as a defense to his criminal conduct. Dr. Edersheim explained that an insanity defense is risky since it entails admitting the defendant is guilty of committing the criminal act, and must prove that the mental state at the time of the crime negates criminal conduct. The defense in this case presents a general conundrum: Can a patchwork of mental conditions definitively cause an individual to be unable to conform his behavior to the requirements of the law? As Professor Pustilnik pointed out, though, the answer to whether the murder happened during a dissociative episode might depend on who is to be convinced. A jury is much less likely to be convinced of the convenient truth of such a dissociative episode than an audience at Harvard Medical School.

In the third case a man faced the death penalty after he killed one woman and tried to kill his wife. His defense introduced recent behavioral genetics research to show the man harbors the “warrior gene”, a variation in the gene encoding monoamine oxidase A, and thereby was born with a predisposition to commit violence. Since he was not responsible for his genetic predisposition to violence, the defense argued, he should be held less responsible for his criminal acts. The jury was swayed and ultimately returned a verdict for less culpable charges.

Dr. Cushman noted that unlike the prior cases, this argument has a sense of design. Experiments demonstrate that we hold individuals less responsible when they are manipulated as part of a plan or scheme. The “warrior gene” implies the criminal behavior is a byproduct of natural selection, or is a sign that some people are designed to be aggressive. This is all beyond the defendant’s control. Because this goes beyond the defendant’s own intentionality, it explains why the genetic argument might have led to a relatively light punishment.

Dr. Edersheim argued against this common intuition and said the defendant should not be exonerated from capital charges. First, the “warrior gene” science is faulty because 35% of Caucasians possess the gene, and yet violence in our population occurs at a far lower rate. Secondly, hundreds or perhaps thousands of genes control human behavior. Given our limited scientific knowledge, a single gene cannot reliably predict a complicated human behavior such as violent criminal conduct. Dr. Edersheim explained that many aspects of law have withstood by the test of time and should not be rapidly replaced by new trendy discoveries. “Crimes have motives, not genes,” Edersheim said.