A Neuroscientist Explains Why Some People May Be Born Criminals

What's to come?
Nov. 15 2011 11:17 AM

Not Guilty by Reason of Neuroscience

Some people’s brains may doom them to a life of crime.

Who's In Charge?

From the book Who’s in Charge?: Free Will and the Science of the Brain, by Michael S. Gazzaniga. Copyright © 2011 by Michael S. Gazzaniga. Reprinted by permission of Ecco, an imprint of HarperCollins Publishers.

On Feb. 19, 1997, a house painter called 911 in Tampa, Fla. He had returned unannounced to a client’s house and through a window saw what appeared to be a naked man throttling a naked woman. When the police arrived, they learned the man hadn’t just strangled Roxanne Hayes; he had stabbed the mother-of-three multiple times, killing her.

The murderer’s name was Lawrence Singleton; he was 69 years old, and he was notorious in California, where 19 years before, he had raped a 15-year-old hitchhiker, Mary Vincent; hacked off her forearms; and left her in a canyon to die. Two vacationers came across her the next morning, walking naked toward the interstate, the stumps of her severed arms raised to prevent further blood loss. Vincent’s description of her attacker was so vivid that it resulted in a police artist’s drawing that his neighbor recognized. Singleton was tried, found guilty, and given what was the maximum sentence at the time in California of 14 years. He was released on parole, however, after eight years of “good behavior,” even though shortly before his release a prison psychiatric evaluation read, “Because he is so out of touch with his hostility and anger, he remains an elevated threat to others’ safety inside and outside prison.” Mary’s mother, Lucy Vincent, said that Mary’s father would carry a .45-caliber pistol and often contemplated killing Singleton.

Because Singleton had written letters to her lawyer threatening her while he was in prison, Mary was terrified after his parole. So were Californians. Residents of every California town that prison authorities tried to settle him in staged angry protests. He was finally settled in a mobile home on the grounds of San Quentin prison until his parole was up and he moved to Florida.

In 2001 Singleton died of cancer while on death row in Florida. Mary Vincent told a reporter that his arrest and death had given her a “tremendous feeling of freedom,” but that she still had such vivid nightmares (during which she had actually dislocated her shoulder, cracked ribs, and smashed her nose) that she was afraid to go to sleep. Divorced, with prostheses that she has modified with spare parts from broken refrigerators and stereo systems, she is now an artist struggling to support two sons.

While you read this, what were your gut feelings and thoughts about Larry Singleton? Did you want him to be locked up and never released (incapacitation)? If you had been Mary’s father, would you, too, have wanted to kill him (retribution)? Or did you want to forgive him, to tell him that it is too bad his brain was unable to inhibit his naturally aggressive tendencies and that perhaps with some treatment he could be more prosocial (rehabilitation)?

Incapacitation, retribution, or rehabilitation are the three choices society has for dealing with criminal behavior. When society considers public safety, it is faced with the decision about which perspective those making and enforcing the laws should take: retribution, an approach focused on punishment of the individual and just desserts; or consequentialism, a utilitarian approach that what is right is what has the best consequences for society.

Neuroscience is beginning to challenge some people’s notions about criminal behavior and what we should do about it. Determinism—the belief that all current and future events, actions, decisions, and behavior are caused by preceding events combined with the laws of nature—disputes long-standing beliefs about what it means to be responsible for one’s actions; some scholars assert the extreme view that humans are never responsible for any of their actions. These ideas challenge the very foundational rules regulating how we live together in social groups. Should people be held accountable for their behavior? If they aren’t, it seems that it would change behavior for the worse, just as studies show that merely reading about determinism results in increased cheating on tests. Is accountability what keeps us civilized? Neuroscience has more and more to say about these questions and is already slowly oozing into the courtroom—prematurely, to the view of most neuroscientists.

Californians thought that Singleton should not have been paroled, and they didn’t want him in their communities. They also thought that certain behavior warranted longer incarceration. They were right, and the parole board was wrong. More recently, the legal system has been looking to neuroscience to provide answers in several different arenas: predicting a person’s future threat (recidivism), determining for whom treatment is possible, and deciding what level of certainty about these determinations is acceptable. Are some crimes just too horrendous to contemplate release? Neuroscience is also illuminating why we have the emotional reactions that we do to antisocial or criminal behavior.

This leads us to the question that if we understand our reactions that have been honed by evolution, can or should we amend them? Are these emotions the sculptors of a civilized society? We have our work cut out for us!

The philosopher Gary Watson has pointed out the simple fact that as we come to think about ourselves, we shape the rules that we decide to live by. Primatologists Michael Tomasello and Brian Hare have argued that we have been domesticating ourselves over thousands of years through ostracizing and killing those who were too aggressive, in essence removing them from the gene pool and modifying our social environment. If they’re right, then we have been making rules for groups to live by and enforcing them throughout our evolutionary history. If neuroscientific findings lead us to think differently about ourselves, our behaviors, and motivations, about the nature of man, about what we are, and about how we should interact; then we may decide to reconstruct our social framework—and our legal structure.

Is our natural inclination for retribution necessary, or is utilitarian accountability sufficient? Is punishment justified? These are questions that haven’t in any way been answered, but they are brought to the fore by research on the brain and what it tells us about who we are. We are going to see that our current legal system has emerged from innate intuitions, honed by evolution, just as our moral systems have been.

Who Done It: Me or My Brain?

Legal systems serve as a social mediator of dealings between people. We should keep in mind the niche construction dynamic when attempting to characterize the law and our concepts of justice and punishment, formed, as they were, by the human brain, mind, and cultural interactions. Legal systems elaborate rights and responsibilities in a variety of ways. In most modern-day societies, the laws made by these systems are enforced through a set of institutions as are the consequences of breaking those laws. When one breaks a law, it is considered to be an offense against the entire society, the state, not an individual. Currently, American law holds one responsible for one’s criminal actions unless one acted under severe duress (a gun pointed at your child’s head, for instance) or one suffers a serious defect in rationality (such as not being able to tell right from wrong). In the United States, the consequences for breaking those laws are based on a system of retributive justice, where a person is held accountable for his crime and is meted out punishment in the form of his “just desserts.” But new research raises the question: Who do we blame in a crime, the person or the brain? Do we want to hold the person accountable or do we want to forgive him because of this determinist dimension of brain function?

From today’s vantage point: It is all about the brain—what it does and does not do. We are born with an intricate brain slowly developing under genetic control, with refinements being made under the influence of epigenetic factors and activity-dependent learning. It displays structured—not random—complexity, with automatic processing, with particular skill sets, with constraints, and with a capacity to generalize. All of these traits evolved through natural selection and provide the foundation for a myriad of cognitive abilities that are separated and represented in different parts of the brain. These parts feature distinct but interrelated neural networks and systems. In short, the brain has distributed systems running simultaneously and in parallel. It has multiple control systems, not just one. It appears to be a determined, finely tuned biological machine.

Neuroscience Oozing Into the Courtroom

The law is complicated and takes into consideration more than just the actual crime. For example, the intention of the perpetrator is also part of the equation. Was the act intentional or accidental? In 1963, Lee Harvey Oswald had the intention of killing President Kennedy when he took his concealed rifle to the building along the parade route, waited there until the president’s motorcade was passing, and shot him. In an Australian case the following year, however, Robert Ryan was judged not to have had the intention to murder when he killed the cashier of a store he had just successfully robbed. While leaving the store, he tripped, accidentally pulled the trigger of his gun, and shot the cashier.

While movies, books, and television portray crimes ending up in a courtroom where intention and many other circumstances are examined, very few criminal cases actually go to trial, only about 3 percent; most are plea bargained out. Once we step into the courtroom, the laboratory of judicial proceedings, neuroscience has an enormous amount to say about the goings-on. It can provide evidence that there is unconscious bias in the judge, jury, prosecutors, and defense attorneys; tell us about the reliability of memory and perception with implications for eyewitness testimony; and inform us about the reliability of lie detecting. Now it’s being asked to determine the presence of diminished responsibility in a defendant, predict future behavior, and determine who will respond to what type of treatment. It can even tell us about our motivations for punishment.

Robert Sapolsky, professor of psychology at Stanford, makes the extremely strong statement: “It’s boggling that the legal system’s gold standard for an insanity defense—M’Naghten—is based on 166-year-old science. Our growing knowledge about the brain makes notions of volition, culpability, and, ultimately, the very premise of a criminal justice system, deeply suspect.” The M’Naghten rules arose after the attempted assassination of British Prime Minister Robert Peel in 1843 and have been used to determine (with a few adjustments) criminal liability in regard to the insanity defense in most common law jurisdictions ever since. The British Supreme Court of Judicature, in answer to one of the questions posed to it by the House of Lords about the insanity law, responded:

“the jurors ought to be told in all cases that every man is presumed to be sane, and to possess a sufficient degree of reason to be responsible for his crimes, until the contrary be proved to their satisfaction; and that to establish a defence on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused was labouring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing; or, if he did know it, that he did not know he was doing what was wrong.”

The question that Sapolsky raises is: Given determinism, given that we are beginning to understand mental states, given we can track down which part of the brain is involved in volitional activity and that it may be impaired, and our growing knowledge that we can be specific about the existence of an impairment and what is causing it, will we view the defendant differently?

At stake in the arguments is the very foundation of our legal system, which holds a person responsible and accountable for his actions. The question is this: Does modern neuroscience deepen our ideas about determinism, and, with more determinism, is there less reason for retribution and punishment? Put differently, with determinism there is no blame, and, with no blame, there should be no retribution and punishment. This is the simmering idea that people are worried about. If we change our mind about these things as a culture, then we are going to change how we deal with this unfortunate aspect of human behavior involving crime and punishment.

Michael S. Gazzaniga is the director of the SAGE Center for the Study of the Mind at the University of California-Santa Barbara. He is the president of the Cognitive Neuroscience Institute and the founding director of the MacArthur Foundation’s Law and Neuroscience Project. His most recent book is Who’s in Charge?: Free Will and the Science of the Brain.