The Anatomy of Violence

by Adrian Raine

  Eight years later, when aged eleven, the children were rated by their parents using a checklist of child behavior problems that included aggression—items like “fights other children,” “attacks others,” “threatens others.”44 I found that high-scoring stimulation seekers at age three—the top 15 percent—were more aggressive at age eleven. To be sure, not all stimulation-seekers became aggressive. But to some extent, the early behavior of young children predicted later aggression. Mauritius may be heaven, but like anywhere else, devils roam. Two children in our study illustrate that while arousal and temperament predict aggression, further complexities must be recognized. One little boy, called Raj, and one little girl, called Joëlle, had nearly the lowest heart rates and the highest levels of stimulation-seeking and fearlessness. They fell into the top sixth percentile of their respective gender on these measures when aged three. So how did these two under-aroused stimulation-seekers turn out later in life?

  Raj turned out to be not just a stimulation-seeker in adulthood, but also a vicious, psychopathic thug who loved riding motorbikes and terrifying and manipulating people. He was the most psychopathic individual in our entire sample of 900 males, with multiple criminal convictions ranging from theft to assault to robbery. In discussing his social relationships and how he came across to others, he admitted, “There are many people scared of me, most of ’em. I’ve got to be dangerous.”45 He actively enjoyed making people uncomfortable. Like many psychopaths, he took pride in his ability to control and regulate people, especially through his reputation of aggression and violence, which gave him status and power within his peer group. In discussing how his friendships were formed, Raj commented, “I want friends out of fear.”46 When someone expresses desires like that, you get the sense you are dealing with a man who knows no fear himself, yet craves fear in his friends.

  Raj’s lifelong fearlessness from age three to age twenty-eight gave rise in part to his aggressive behavior, which in turn allowed him to obtain rewards and status from those who feared him. It was reinforced so strongly that it became his modus operandi. When asked about his girlfriend, he mused for a while and then laughed. “Yeh … I think she’s scared of me too!” he said.47 It speaks to the callousness and cold-bloodedness that is typical of psychopaths. Just as we saw earlier in our evolutionary perspective on violence and cheating, psychopathy can be a successful reproductive strategy, with power and control over others bringing resources that translate into greater reproductive fitness.

  Raj’s authority over others through threats and violence pervaded even his intimate social relations. His ability to make people frightened likely enhanced his enjoyment of sexual relations with his girlfriend, in a similar way to the enjoyment that sadistic rapists obtain in terrifying, dominating, and controlling their victims.

  Yet was he really that fearless? Surely something must have scared him, sometime. What if he met others like himself?

  Nothing can frighten me. They want to fight with me? I beat them up—that’s it, that’s all. Ye know what I mean? I just cut their face, ye know what I mean?48

  He really had neither a sense of fear nor a concern for others. Because he lacked the empathy needed to appreciate others’ pain, there was no empathy holding him back from mutilating people’s faces. He lay at the extreme of psychopathy—at the extreme of fearlessness.

  Did he sometimes feel sorry for the victims of his violence? Did he have a sense of conscience? Raj’s reply: “No, ’cos it’s them that searched for it.”49 Psychopaths are always more than willing to blame others to justify their actions. They apply the “just deserts” principle to defend their heinous actions. Others get what they deserve because of how they behave. This gave Raj free license to do almost anything. Life for renegade Raj and other psychopaths is essentially jeux sans frontières—games without boundaries. They are playing out a life full of fun and excitement. This mind-set can make for a nasty piece of work—a callous, unemotional, heartless, cold-blooded, stop-at-nothing psychopath. And it’s caused by low physiological arousal, fearlessness, and stimulation-seeking early in life.

  The little girl, Joëlle, also turned out to be a fearless stimulation-seeker later in life, but in a very different way. She went on to become Miss Mauritius and obtained her excitement in life though very different avenues.

  As an adult, her prevailing memory of herself as a child was one of a thirst for discovery. To try everything out, to explore the world, and to put herself forward. When asked about her memories, Joëlle said, “I wanted to discover so many things about life. The most important thing for me was to express myself.”50 She too wanted to act on the environment, but in a different way from Raj. The desire for discovery, to experience the world, and to give full expression to one’s fearless, stimulation-seeking potential need not always result in criminality. Joëlle went on to live a fulfilled, aggression-free life because despite the biological and temperamental predispositions for an antisocial lifestyle, she was a kind, generous, and sensitive person. She had other factors that protected her from the extreme outcome of a psychopath, and perhaps being a girl, combined with all the genetic and environmental baggage that comes along with a woman’s world, made a difference.

  In broad terms, the difference between Raj and Joëlle is not unlike that between Ted Kaczynski and our fearless bomb-disposal expert. Biology is not destiny. The same biological predispositions can result in very different outcomes. At the same time, these early biological warning signs can give us a sense of potential problems on the road ahead. Indeed, when it comes to understanding outcomes for violence through the autonomic nervous system, our notion of conscience is key.

  CONSCIENCE CONQUERS CRIME

  Have you ever thought of killing someone? No? Well, aren’t you a Goody Two-shoes.

  Seventy-six percent of “normal” men have had at least one homicidal fantasy. For normal women the rate is a bit lower, at 62 percent.51 Who do you want to kill? Men think about killing co-workers, while women want to kill their family members, especially stepparents. That latter fantasy fits our evolutionary account of homicide—you kill those not genetically related to you. Why do you want to kill? The most common reason is a lover’s quarrel, but apparently 3 percent of you have fantasized about killing someone just to experience what it is like to kill someone.52

  Alfred Hitchcock had a good sense of the surprising range of violent thoughts throughout American society. In his movie Strangers on a Train there is a cocktail party scene where a woman imagines a killing:

  I think it would be a wonderful idea. I can take [my husband] out in the car and when we get to a very lonely spot, knock him on the head with a hammer, pour gasoline over him and over the car, and set the whole thing ablaze.53

  And she laughs.

  I hope I never meet some of you, and yet I imagine you have not killed anyone. Why? Because when you really think hard about it, when you put yourself right there in the situation of doing it, you can’t follow through. Something’s holding you back. I know I can’t follow through, no matter how much I’ve wanted to kill some of my critics. This thing we call a conscience kicks in. It’s made up of gut reactions and feelings generated in part by our autonomic nervous system and pulls us back from the brink. And it goes beyond heart rate. What we’re talking about here is a symphony of classical conditioning and autonomic reactions that inspire or dissuade us from taking antisocial actions.

  How can we measure something as abstract as “conscience”? Well, sweat is a good place to start—specifically something known as classical conditioning as measured by skin conductance. Let’s take a quick trip to the laboratory, the kitchen, and then back to the laboratory again.

  In the laboratory, skin conductance54 is measured with small electrodes. We place them on the distal phalanges—the tips—of the first and second fingers of the hand. We then pass a very small electrical current across these two electrodes—so small you would never feel it. The more you sweat, the better the current will be conduc
ted. These very tiny electrical changes—as small as .01 microsiemens (one hundred millionths of a siemen, a unit of conductance)—are amplified so that they can be seen and measured by computer software.

  Variations in the size of a subject’s sweat response to a simple tone played over headphones reflect differences in the extent to which the subject allocated attentional resources to process the tone.55 When you pay attention to a sound, the prefrontal cortex, amygdala, hippocampus, and hypothalamus are activated.56 Some of these “lower” brain areas—the hypothalamus and brain stem—stimulate sweating.57 So people sweat a bit more when thinking or listening to something. Although the sweat response is a peripheral autonomic measure, it is nevertheless a powerful measure of central nervous system processing.58 The bigger the skin-conductance response, the greater the degree of attentional processing.

  Let’s get back to the vexing question of quantifying exactly what a “conscience” is. What ultimately gives us that sense of right and wrong in life? I believe the answer lies in biosocial theory.59 We can think of a conscience as essentially a set of classically conditioned emotional responses. Criminals and psychopaths show poor fear conditioning—in part because they are chronically under-aroused. Because of this lack of fear conditioning, they lack a fully developed conscience. And it is that lack of conscience—a sense of what is right and what is wrong—that makes them who they are.60

  It goes like this. Classical conditioning involves learning an association between two events in time. When an initially neutral event (the conditional stimulus) is closely followed by an aversive event (the unconditional stimulus), that initially neutral stimulus will develop the properties of the aversive stimulus. In the classic case of Pavlov’s dogs, a bell was paired with the later presentation of food. Food to hungry dogs automatically elicits an unconditional response: salivation. After a number of pairings of the bell with the food, the bell by itself came to elicit the salivation. The dogs learned a relationship between the sound of a bell and the later presentation of food. They conditioned.

  Now from the lab to the kitchen. Young children are not too different from Pavlov’s dogs. Take the scenario of a small child stealing a cookie from the kitchen. Punishment by the parent, like scolding or a slap, elicits an unconditional response—the child is upset and hurt. After a number of similar learning trials, the sight of the cookie—or just the thought of stealing the cookie—will elicit an uncomfortable feeling, a conditioned response. It is that discomfort that keeps the child from engaging in the theft. The storage in the brain of similar “conditioned emotional responses” developed early in life in lots of different situations accumulates to form what we call “conscience.” And that’s what stops you from killing someone.

  In this analysis, socialized individuals develop a feeling of uneasiness even thinking about stealing something or assaulting someone. That’s because such thoughts elicit unconscious memories of punishment that took place early in life, for mild misdemeanors like theft or behaving aggressively. Haven’t you sometimes said when discussing a crime to your friend, “I could never even think of doing such a thing”? Now you can understand part of the reason. You rarely if ever contemplate such events because even the thought of such acts generates previously conditioned emotional responses that produce discomfort in you. Criminal thoughts then get rubbed out of your cognitive repertoire—they are off your radar screen.

  There’s another side to this that I find interesting. There are some offenses that have an almost unnatural feel about them—they don’t seem all that criminal. Think about cheating on your taxes, for example. Imagine pumping up your yearly charitable contributions from $100 to $200. This act does not seem quite as “offensive” as other offenses. I mean, you did give $100 to charity, didn’t you? You’re not such a bad person, are you? And perhaps the reason it does not seem so bad—and why you might do it—is that there is no convincing analogue of tax evasion in childhood. Parents do not punish us for these “white-collar crimes” but instead focus on more obvious things like stealing and fighting. Consequently, some of us have not developed much of a “conscience” for these acts. That may be why white-collar crimes are committed by people who are supposedly reasonable citizens in society—and why you might think they are not as serious as other criminal offenses.

  Plagiarism is another example. It is absolutely rampant in students. The self-report survey I conducted on Hong Kong undergraduates showed that 67 percent had passed off other people’s essays as their own work. Similarly, 66.6 percent had copied others’ work to meet a course requirement. Despite strict institutional prohibitions against such actions, it goes on unchecked. Perhaps less surprising to you—likely because you have done it too—is that 88.3 percent had bought pirated software or DVDs, while 94.2 percent had illegally downloaded music or movies. Again, there is no convincing childhood analogue of these actions that gets punished, and hence little or no conscience about perpetrating those acts. Parents may pass off their own ideas as their child’s when helping them in their schoolwork—and praise their child when rereading that terrific-looking piece of work a few days later. We may even be unknowingly socializing our children into white-collar antisocial habits.

  Now to the evidence. A systematic review of all studies conducted on adult criminals, psychopaths, and antisocial adolescents concluded that there is overwhelming evidence for poor fear conditioning in offenders.61 Nevertheless, living a criminal way of life might cause the poor conditioning, rather than poor conditioning being a causal agent of later crime. While dozens of studies found poor fear conditioning in criminals and psychopaths, none prospectively tested whether poor fear conditioning early in life predicted adult crime. What was really needed was a prospective longitudinal study to prove the point.

  FEARLESS TOTS TODAY—RUTHLESS THUGS TOMORROW

  Onto the conditioning stage steps Yu Gao, from Beijing Normal University in mainland China. Gao had come to study for her PhD with me at the University of Southern California in 2003. In a collaboration that would span three academic generations, she shed light on the darker developmental question of whether poor fear conditioning predisposes someone to crime.

  My own PhD supervisor, Peter Venables, had taken a long look at the fear-conditioning data he had collected in Mauritius and concluded that there was no conditioning. I bought into Peter’s conclusions because, well, he was after all one of the world’s leading authorities on psychophysiology. You are hardly going to question your own supervisor, are you?

  Gao was less gullible and more gutsy. It was an example of where fresh minds give rise to new perspectives, innovation, and progress. We had the help of Mike Dawson, a world-leading authority on fear conditioning. Gao launched herself into the data and with her strong statistical expertise she convincingly demonstrated that fear conditioning had indeed occurred in the three-year-olds. Peter had been too pessimistic—his conditioning paradigm had indeed worked.

  Of course, like everything else in life there are differences between us in the degree of fear conditioning. Some condition, and some do not. That’s the interesting bit that Gao pounced on. Recall that mothers brought their three-year-old children into the laboratory—1,795 of them in all. Small electrodes were placed on the little fingers of the toddlers to measure skin conductance. Headphones were placed on their heads to deliver the auditory tone stimuli. They sat on their mother’s lap for security and comfort. Then the conditioning experiment began.

  On some trials, a low-pitched tone predicted that ten seconds later the children would be blasted with an unpleasant loud noise. On other trials, a high-pitched tone would be presented and nothing would happen. The children were not told about the association between the low-pitched tone and the nasty noise. And yet in just three conditioning trials their brains worked it out. As a whole group, the children gave a bigger skin-conductance response to the low tone than to the high tone. They had become conditioned and developed anticipatory fear to the initially neutral tone that had b
een paired up with the aversive tone.

  We sit back and let twenty years go by. The tots are now twenty-three-year-old adults. We search all the court records on the island to see which children grew up to become adult criminals. Out of the 1,795 subjects, 137 had had a conviction. Gao matched each offender with two non-offenders on gender, age, ethnicity, and social adversity—a total of 274. This epidemiological “case-control design” ensures that any group differences cannot be due to group differences on these demographic measures. Gao then looked at how the two groups fared in their ability to develop conditioned fear twenty years earlier, at age three.

  Figure 4.1 Fear conditioning at age three in relation to crime at age twenty-three. A greater response to the CS+ compared to the CS– indicates fear conditioning.

  The results were striking. Remember that to show fear conditioning you must show a larger skin conductance response to the low-pitched tone, called the CS+, that predicts the unpleasant tone compared with the high-pitched tone, the CS, that does not predict the aversive tone. Figure 4.1 illustrates the finding. The normal control group showed significant fear conditioning. Their sweat response to the low-pitched (CS+) tone was much bigger than their response to the high-pitched (CS–) tone. Yet the criminals-to-be, back at age three, showed no sign of conditioning at all. They were flat-liners—as a group they did not show any fear conditioning. This finding by Yu Gao demonstrated for the first time that an early impairment in autonomic fear conditioning acts as a predisposition to criminality in adulthood.62