Alex’s story highlights a deep central point: when your biology changes, so can your decision making, your appetites, and your desires. The drives you take for granted (“I’m a hetero/homosexual,” “I’m attracted to children/adults,” “I’m aggressive/not aggressive,” and so on) depend on the intricate details of your neural machinery. Although acting on such drives is popularly thought to be a free choice, the most cursory examination of the evidence demonstrates the limits of that assumption; we will see further examples in a moment.
The lesson of Alex’s story is reinforced by its unexpected follow-up. About six months after the brain surgery, his pedophilic behavior began to return. His wife took him back to the doctors. The neuroradiologist discovered that a portion of the tumor had been missed in the surgery and was regrowing—and Alex went back under the knife. After the removal of the remaining tumor, his behavior returned to normal.
Alex’s sudden pedophilia illustrates that hidden drives and desires can lurk undetected behind the neural machinery of socialization. When the frontal lobe is compromised, people become “disinhibited,” unmasking the presence of the seedier elements in the neural democracy. Would it be correct to say that Alex was “fundamentally” a pedophile, merely socialized to resist his impulses? Perhaps, but before we assign labels, consider that you probably would not want to discover the alien subroutines that lurk under your own frontal cortex.
A common example of this disinhibited behavior is seen in patients with frontotemporal dementia, a tragic disease in which the frontal and temporal lobes degenerate. With the loss of the brain tissue, patients lose the ability to control the hidden impulses. To the frustration of their loved ones, these patients unearth an endless variety of ways to violate social norms: shoplifting in front of store managers, removing their clothes in public, running stop signs, breaking out in song at inappropriate times, eating food scraps found in public trash cans, or being physically aggressive or sexually transgressive. Patients with frontotemporal dementia commonly end up in courtrooms, where their lawyers, doctors, and embarrassed adult children must explain to the judge that the violation was not the perpetrator’s fault, exactly: much of their brains had degenerated, and there is currently no medication to stop it. Fifty-seven percent of frontotemporal dementia patients display socially violating behavior that sets them up for trouble with the law, as compared to only 7 percent of Alzheimer’s patients.7
For another example of changes in the brain leading to changes in behavior, consider what has happened in the treatment of Parkinson’s disease. In 2001, families and caretakers of Parkinson’s patients began to notice something strange. When patients were given a drug called pramipexole, some of them turned into gamblers.8 And not just casual gamblers—pathological gamblers. These were patients who had never before displayed gambling behavior, and now they were flying off to Vegas. One sixty-eight-year-old man amassed losses of over $200,000 in six months at a series of casinos. Some patients became consumed with internet poker, racking up unpayable credit card bills. Many did what they could to hide the losses from their families. For some, the new addiction reached beyond gambling to compulsive eating, alcohol consumption, and hypersexuality.
What was going on? You may have seen the awful plunder of Parkinson’s, a degenerative disorder in which the hands tremble, the limbs become stiff, facial expressions turn blank, and the patient’s balance progressively worsens. Parkinson’s results from the loss of cells in the brain that produce a neurotransmitter known as dopamine. The treatment for Parkinson’s is to increase the patients’ dopamine levels—usually by increasing the body’s production of the chemical, and sometimes by using medications that directly bind to dopamine receptors. But it turns out that dopamine is a chemical on double duty in the brain. Along with its role in motor commands, it also serves as the main messenger in the reward systems, guiding a person toward food, drink, mates, and all things useful for survival. Because of its role in the reward system, imbalances in dopamine can trigger gambling, overeating, and drug addiction—behaviors that result from a reward system gone awry.9
Physicians now watch out for these behavioral changes as a possible side effect of dopamine drugs like pramipexole, and a warning is clearly listed on the label. When a gambling situation crops up, families and caretakers are instructed to secure the credit cards of the patient and carefully monitor their online activities and local trips. Luckily, the effects of the drug are reversible—the physician simply lowers the dosage of the drug and the compulsive gambling goes away.
The lesson is clear: a slight change in the balance of brain chemistry can cause large changes in behavior. The behavior of the patient cannot be separated from his biology. If we like to believe that people make free choices about their behavior (as in, “I don’t gamble because I’m strong-willed”), cases like Alex the pedophile, the frontotemporal shoplifters, and the gambling Parkinson’s patients may encourage us to examine our views more carefully. Perhaps not everyone is equally “free” to make socially appropriate choices.
WHERE YOU’RE GOING, WHERE YOU’VE BEEN
Many of us like to believe that all adults possess the same capacity to make sound choices. It’s a nice idea, but it’s wrong. People’s brains can be vastly different—influenced not only by genetics but by the environments in which they grew up. Many “pathogens” (both chemical and behavioral) can influence how you turn out; these include substance abuse by a mother during pregnancy, maternal stress, and low birth weight. As a child grows, neglect, physical abuse, and head injury can cause problems in mental development. Once the child is grown, substance abuse and exposure to a variety of toxins can damage the brain, modifying intelligence, aggression, and decision-making abilities.10 The major public health movement to remove lead-based paint grew out of an understanding that even low levels of lead can cause brain damage that makes children less intelligent and, in some cases, more impulsive and aggressive. How you turn out depends on where you’ve been. So when it comes to thinking about blameworthiness, the first difficulty to consider is that people do not choose their own developmental path.
As we’ll see, this understanding does not get criminals off the hook, but it’s important to lead off this discussion with a clear understanding that people have very different starting points. It is problematic to imagine yourself in the shoes of a criminal and conclude, “Well, I wouldn’t have done that”—because if you weren’t exposed to in utero cocaine, lead poisoning, or physical abuse, and he was, then you and he are not directly comparable. Your brains are different; you don’t fit in his shoes. Even if you would like to imagine what it’s like to be him, you won’t be very good at it.
Who you even have the possibility to be starts well before your childhood—it starts at conception. If you think genes don’t matter for how people behave, consider this amazing fact: if you are a carrier of a particular set of genes, your probability of committing a violent crime goes up by eight hundred and eighty-two percent. Here are statistics from the U.S. Department of Justice, which I’ve broken down into two groups: crimes committed by the population that carries this specific set of genes and by the population that does not:
Average Number of Violent Crimes Committed Annually in the United States
Offense
Aggravated Assault
Homicide
Armed robbery
Sexual assault Carrying the genes
3,419,000
14,196
2,051,000
442,000 Not carrying the genes
435,000
1,468
157,000
10,000
In other words, if you carry these genes, you’re eight times more likely to commit aggravated assault, ten times more likely to commit murder, thirteen times more likely to commit armed robbery, and forty-four times more likely to commit sexual assault.
About one-half of the human population carries these genes, while the other half does not, making the first half much
more dangerous indeed. It’s not even a contest. The overwhelming majority of prisoners carry these genes, as do 98.4 percent of those on death row. It seems clear enough that the carriers are strongly predisposed toward a different type of behavior—and these statistics alone indicate that we cannot presume that everyone is coming to the table equally equipped in terms of drives and behaviors.
We’ll return to these genes in a moment, but first I want to tie the issue back to the main point we’ve seen throughout the book: we are not the ones driving the boat of our behavior, at least not nearly as much as we believe. Who we are runs well below the surface of our conscious access, and the details reach back in time before our birth, when the meeting of a sperm and egg granted us with certain attributes and not others. Who we can be begins with our molecular blueprints—a series of alien codes penned in invisibly small strings of acids—well before we have anything to do with it. We are a product of our inaccessible, microscopic history.
By the way, as regards that dangerous set of genes, you’ve probably heard of them. They are summarized as the Y chromosome. If you’re a carrier, we call you a male.
* * *
When it comes to nature and nurture, the important point is that you choose neither one. We are each constructed from a genetic blueprint and born into a world of circumstances about which we have no choice in our most formative years. The complex interactions of genes and environment means that the citizens of our society possess different perspectives, dissimilar personalities, and varied capacities for decision making. These are not free-will choices of the citizens; these are the hands of cards we’re dealt.
Because we did not choose the factors that affected the formation and structure of our brain, the concepts of free will and personal responsibility begin to sprout with question marks. Is it meaningful to say that Alex made bad choices, even though his brain tumor was not his fault? Is it justifiable to say that the patients with frontotemporal dementia or Parkinson’s should be punished for their bad behavior?
If it seems we’re heading in an uncomfortable direction—one that lets criminals off the hook—please read on, because I’m going to show the logic of a new argument piece by piece. The upshot will be that we can have an evidence-based legal system in which we will continue to take criminals off the streets, but we will change our reasons for punishment and our opportunities for rehabilitation. When modern brain science is laid out clearly, it is difficult to justify how our legal system can continue to function without it.
THE QUESTION OF FREE WILL, AND WHY THE ANSWER MAY NOT MATTER
“Man is a masterpiece of creation, if only because no amount of determinism can prevent him from believing that he acts as a free being.”
—Georg C. Lichtenberg, Aphorisms
On August 20, 1994, in Honolulu, Hawaii, a female circus elephant named Tyke was performing in front of a crowd of hundreds. At some point, for reasons masked in elephant neurocircuitry, she snapped. She gored her groomer, Dallas Beckwith, and then trampled her trainer, Allen Beckwith. In front of the terrified crowd, Tyke burst through the barriers of the arena; once outside, she attacked a publicist named Steve Hirano. The entire series of bloody events was captured on the video cameras of the circusgoers. Tyke loped away down the streets of the Kakaako district. Over the next thirty minutes, Hawaiian police officers gave chase, firing a total of eighty-six shots at the elephant. Eventually, the damage added up and Tyke collapsed, dead.
Elephant gorings like this are not rare, and the most bizarre parts of their stories are the endings. In 1903, Topsy the elephant killed three of his handlers on Coney Island and, in a display of new technology, was electrocuted by Thomas Edison. In 1916, Mary the elephant, a performer with the Sparks World Famous Shows, killed her keeper in front of a crowd in Tennessee. Responding to the bloodthirsty demands of the community, the circus owner had Mary hung on a massive noose from a railroad derrick car, the only known elephant-hanging in history.
We do not even bother to ask the question of blame in regards to an off-kilter circus elephant. There are no lawyers who specialize in defending elephants, no drawn-out trials, no arguments for biological mitigation. We simply deal with the elephant in the most straightforward manner to maintain public safety. After all, Tyke and Topsy and Mary are understood simply to be animals, nothing but a weighty collection of elephantine zombie systems.
In contrast, when it comes to humans the legal system rests on the assumption that we do have free will—and we are judged based on this perceived freedom. However, given that our neural circuitry runs fundamentally the same algorithms as those of our pachyderm cousins, does this distinction between humans and animals make sense? Anatomically, our brains are made of all the same pieces and parts, with names like cortex, hypothalamus, reticular formation, fornix, septal nucleus, and so on. Differences in body plans and ecological niches slightly modify the connectivity patterns—but otherwise we find in our brains the same blueprints found in elephant brains. From an evolutionary point of view, the differences between mammalian brains exist only in the minute details. So where does this freedom of choice supposedly slip into the circuitry of humans?
* * *
As far as the legal system sees it, humans are practical reasoners. We use conscious deliberation when deciding how to act. We make our own decisions. Thus, in the legal system, a prosecutor must not merely show a guilty act, but a guilty mind as well.11 And as long as there is nothing hindering the mind in its control of the body, it is assumed that the actor is fully responsible for his actions. This view of the practical reasoner is both intuitive and—as should be clear by this point in the book—deeply problematic. There is a tension between biology and law on this intuition. After all, we are driven to be who we are by vast and complex biological networks. We do not come to the table as blank slates, free to take in the world and come to open-ended decisions. In fact, it is not clear how much the conscious you—as opposed to the genetic and neural you—gets to do any deciding at all.
We’ve reached the crux of the issue. How exactly should we assign culpability to people for their varied behavior, when it is difficult to argue that the choice was ever really available?
Or do people have a choice about how they act, despite it all? Even in the face of all the machinery that constitutes you, is there some small internal voice that is independent of the biology, that directs decisions, that incessantly whispers the right thing to do? Isn’t this what we call free will?
* * *
The existence of free will in human behavior is the subject of an ancient and heated debate. Those who support free will typically base their argument on direct subjective experience (I feel like I made the decision to lift my finger just now), which, as we are about to see, can be misleading. Although our decisions may seem like free choices, no good evidence exists that they actually are.
Consider a decision to move. It feels as though free will leads you to stick out your tongue, or scrunch up your face, or call someone a name. But free will is not required to play any role in these acts. Take Tourette’s syndrome, in which a person suffers from involuntary movements and vocalizations. A typical Touretter may stick out his tongue, scrunch up his face, call someone a name—all without choosing to do so. A common symptom of Tourette’s is called coprolalia, an unfortunate behavior in which the person bursts out with socially unacceptable words or phrases, such as curse words or racial epithets. Unfortunately for the Tourette’s patient, the words coming out of their mouths are usually the last things they would want to say in that situation: the coprolalia is triggered by seeing someone or something that makes the exclamation forbidden. For example, upon seeing an obese person they may be compelled to shout “Fatso!” The forbidden quality of the thought drives the compulsion to shout it out.
The motor tics and inappropriate exclamations of Tourette’s are not generated with what we would call free will. So we immediately learn two things from the Tourette’s patient. First, sophisticated actio
n can occur in the absence of free will. This means that witnessing a complicated act in ourselves or someone else should not convince us that there was free will behind it. Second, the Tourette’s patient cannot not do it: they cannot use free will to override or control what other parts of their brain have decided to do. They have no free won’t. What the lack of free will and the lack of free won’t have in common is the lack of “free.” Tourette’s syndrome provides a case in which the zombie systems make decisions and we all agree that the person is not responsible.
Such a lack of free decisions is not restricted to Tourette’s. We see this also with so-called psychogenic disorders in which movements of the hands, arms, legs, and face are involuntary, even though they certainly look voluntary: ask such a patient why she is moving her fingers up and down, and she will explain that she has no control over her hand. She cannot not do it. Similarly, as we saw in the previous chapter, split-brain patients can often develop alien hand syndrome: while one hand buttons up a shirt, the other hand works to unbutton it. When one hand reaches for a pencil, the other bats it away. No matter how hard the patient tries, he cannot make his alien hand not do what it’s doing. The decisions are not “his” to freely start or stop.