“In the beginning, there was nothing. And God said, ‘Let there be Light.’ And there was still nothing. But you could see it.”

—Anonymous

LOOKING INSIDE THE BRAIN OF A PSYCHOPATH

“Parents of violent kids think, ‘What did I do wrong?’” says Adrian Raine, a “Penn Integrates Knowledge” professor who holds joint appointments in criminology and psychiatry at the University of Pennsylvania. “When the kids come from a good home, the answer may be absolutely nothing. A biological deficit may be to blame.”1

And now we are beginning to be able to “see” the deficit.

One of the most powerful methods of seeing inside the brain involves magnetic resonance imaging—often shortened to MRI. In this technique, water molecules are tickled to cause them to burp out electromagnetic waves that are only slightly different in frequency from the electromagnetic waves our eyes see as light. Since different types of tissue have different amounts of water, we can use clever technical legerdemain to “see” the different tissue types on photographs that look very similar to x-ray images.

A complete slice of the brain can be seen—“imaged”—in the same way that you are scanning your eyes across this page. Since an image can be produced very quickly (only twenty milliseconds—about one-fifth of the time it takes to blink your eye), it is possible to produce a number of MRI pictures one right after another as if filming a movie. In this fashion, as cells and molecules carry out the work of the brain, the differences between images can clearly be seen. This video version of MRI is called functional MRI, or fMRI. MRI compares to fMRI in the same way a picture of you posed with a cheesy smile in your sixth-grade class picture compares to an old home movie of you throwing a snit. You can see what you looked like from the still picture, but you can tell a lot more about how you functioned from the home movie.2

EMOTION AND LANGUAGE

The following illustrations, from an fMRI study by Yale psychologist and neuroscientist Kent Kiehl and his group, reveal that many regions of the brain in emotionally excited psychopaths function differently than in normal people. The upper two figures of the “generic brain” show areas, highlighted in white, where criminal psychopaths had much less activity than normal subjects when repeating emotionally charged words like blood, sewer, hell, and rape.³ These neural areas relate to limbic and paralimbic levels—very old parts of the brain in evolutionary terms that are also found in fishes and reptiles. The bottom two figures, on the other hand, show areas of the generic brain where criminal psychopaths had greater activity (also highlighted in white) related to emotion than normal subjects. This increased activity may be caused by the weak input from the limbic system, which forces psychopaths to use alternative neural structures to grapple with emotional information.4

Fig. 4.1. Four different views of a psychopath's brain. The white spots are the areas of interest.

Finding neural differences between psychopaths and normal people looks as simple as snapping a picture with a fancy camera—and in some sense, despite the acrobatics involved in processing the data, it is simple. But occasionally it's nice to step back and admire the intricate logistics behind these types of experiments. For the images we just saw, simply being able to get the psychopaths to where they could be imaged was no easy matter. The eight psychopaths involved in the study were hauled under heavy guard fifty miles from the maximum-security prison in Abbotsford, British Columbia, to the University of British Columbia Hospital's magnetic resonance imaging unit. As Kiehl wryly understates: “The work is never boring.”5

LOW RESPONSE TO THREATENING STIMULI AND EMPATHY IMPAIRMENT

Another study has shown that a psychopath is likely to have a weird corpus callosum—the nerve superhighway orchestrating the flow of information between the brain's two hemispheres.⁶ The white matter volume of the corpus callosum of psychopaths is nearly a quarter larger than normal, but, like pulled taffy, the highway's length is increased while its thickness is decreased. These differences in neural structure seem to go hand in hand with the curious gaps in emotion and creepy interpersonal skills of psychopaths, along with their low involuntary reactions to stress. Why might the corpus callosum abnormalities cause these personality differences? It might be because a poorly structured corpus callosum inhibits communication between the two halves of the brain—in particular, it doesn't do its normal job of allowing the left brain to inhibit and control the negative moods that can be generated by the right hemisphere. This may cause the expression of the aggressive, unregulated behavior that psychopaths can display.⁷

Researchers feel that corpus callosum abnormalities may be caused by a problem in the development of a psychopath's brain. Pruning—a natural, internal process of tidying up the brain by shearing off unused neurons—may not take place properly. Or the neurons may be too heavily encased in sheaths of myelin—insulating trestles of glial white matter.

Fig. 4.2. This cross section demonstrates some of the brain's internal structures. The amygdala and hippocampus are actually located deep within the brain but are shown as an overlay in the approximate areas that they are located.

LACK OF ANXIETY

The amygdala is actually an almond-sized pair of organs deep in the brain that cause a knee-jerk “fight-or-flight” reaction when people are startled. In some circumstances, psychopaths have lazier amygdala than normal people, as was discovered when a group of psychopaths was exposed to the smell of rotten yeast (stinky smells as a rule cause the amygdala to jerk to attention). Researchers think that routinely blasé amygdalae and other related structures in psychopaths may leave them feeling restless, spurring them to raise hell just for the resulting excitement. The psychopaths’ nonchalant neural reactions may also be related to their strange lack of fear—which also appears to have a genetic basis.8 Lack of fear may in turn throttle the development of a psychopath's conscience. Some researchers feel that amygdala dysfunction lies at the very core of psychopathy.⁹

EXECUTIVE DYSFUNCTION

Peculiarities resulting from injuries or congenital differences in the area of the brain behind the forehead, especially in the orbitofrontal and ventromedial cortices near the eyes, seem to be the cause of the “executive dysfunction” often seen in antisocial children and adults.10 This means that antisocials often have trouble organizing their behavior. For example, a typical waitress job, which might involve fielding requests from a dozen different tables while interacting with the hostess, cooks, and busboys, would be difficult for someone with noticeable executive dysfunction. Orbitofrontal dysfunction in particular seems to release the normal brakes on aggressive and hostile impulses, while dorsolateral dysfunction contributes to an inability to learn from punishment.

Adrian Raine has conducted many studies that have done much to revolutionize our understanding of the neurological foundations of psychopathy. Raine has the seemingly mild-mannered look of an accountant—indeed, he was an accountant. His first two years in the workforce were as an airline accountant for British Airways. However, after receiving a doctorate in psychology, Raine gained a seasoned understanding of psychopathy by spending four years working as a prison psychologist in two top-security prisons in England. A key to the depth of Raine's research breakthroughs is not only his hardened “real-world” background, but also the way he combines knowledge from this background with an astonishing breadth of hard and soft science academic interests, which include brain imaging, psychophysiology, neurochemistry, antisocial behavior, schizotypal personality, and alcoholism.

Fig. 4.3. Damage or dysfunction in these three areas of the prefrontal cortex—the dorsolateral, orbitofrontal, and ventromedial cortices—appears to be strongly associated with antisocial behavior. All of the areas indicated are toward the front of the brain, near the eyes. The left picture is a side view, while the picture on the right shows a view looking up toward the brain from its bottom.

“Why doesn't everyone assault others or act violently?” asks Raine.

One reason is that most of us are good at fear conditioning and we've been punished in childhood for doing minor things like stealing or hitting friends. So we've learned the association between antisocial behavior and punishment and therefore feel fear when we even contemplate an antisocial act. But not everyone is able to form these conditioned responses with equal facility. While some people have biological systems that make it easy, others have biological systems that make it hard. If you are an individual whose right orbital cortex is not functioning well, you're biologically disadvantaged in developing a conscience.11

Oddly enough, one study has shown that murderers who have a normal family upbringing have even lower function in their right orbitofrontal cortical areas than murderers who were abused during childhood. Perhaps murderers “without a psychosocial ‘push’ toward violence require a greater neurobiological ‘push.’”¹² In other words, children with less severe neurological problems may be helped by having a normal upbringing—but children with more severe neurological difficulties may not be.

Kind and conscientious people who suffer brain damage in ventromedial areas can suddenly have a complete change in personality and begin to act like psychopaths. Despite seemingly normal intelligence, these “pseudopsychopaths” are often found to have subtly impaired reasoning skills. For example, they may continue to make bad choices in rigged experimental card games even after they understand intellectually how the game is rigged and how they could easily play to win.13

EMOTIONAL CONTROL—AFFECTIVE AND PREDATORY MURDERERS

Imaging is not only allowing us to see into the brains of psychopaths, it is also providing clues about the neural circuitry that underlies their motives. For example, murderers have long been divided into two types: affective and predatory. Affective murderers murder under the influence of emotion. They show little planning to their passionate acts, which often take place in domestic settings. A typical example of an affective murderer is actor Marlon Brando's son Christian, who, while in a drunken rage, murdered the abusive boyfriend of his pregnant, mentally disturbed sister. Predatory murderers, on the other hand, are coldly unemotional, far more controlled, and are more likely to attack a stranger, often using a carefully planned setup. Richard Kuklinski, who “whacked” people for the Gambino crime family, is a good example of a predatory murderer. He perfunctorily explained his motives for killing nearly a hundred people on the HBO film The Iceman: “It was due to business.” (The first might be seen as committing a crime of passion, while the second is premeditated.)

The two very different sets of neural circuitry involved in affective versus predatory murderers are thought to be similar to the two different sets of circuitries seen in animals such as cats. The affective circuit, for example, is activated if Fluffy the cat is trapped by a barking dog—Fluffy's hackles are raised, her back is arched, and she hisses and spits loudly, pinning her ears back and displaying her teeth. If you are unwise enough to try to pick Fluffy up at this point, she is likely to mindlessly attack you. A completely different set of circuits is involved in predatory behavior, as when Fluffy is stalking a bird. She is snake-silent during this time, with ears and eyes focused; she moves slowly and close to the ground. You can safely pick up Fluffy when she's in this predatory mode, although her paws might pinwheel as she still tries to move toward her target.14

As expected, human imaging of affective and predatory murderers has revealed profound differences in how their brains operate—similar to the neural circuit differences known to operate in Fluffy the cat. The affective murderer shows lethargic activity in the prefrontal cortex, the area that normally reins in impulses.¹⁵ The predatory murderer, however, shows good functioning in the prefrontal cortex, which is, as Raine slyly notes, “consistent with the role of an intact prefrontal cortex in allowing him to regulate his behavior for nefarious ends.”¹⁶ In short, the predatory murderer is well aware of what he plans to do. Emotion-related areas of the brain (specifically, the midbrain, amygdala, hippocampus, and thalamus) in both sets of murderers were found to be metabolically turbocharged compared to normal people's.^a. It's thought that the revved-up, party neural atmosphere predisposes both groups of murderers to an aggressive temperament. But only the predatory murderers are able to channel their aggressive impulses into slow-motion torture through bullying, manipulation, deceit—or carefully planned murder.

PROBLEMS WITH ABSTRACT REASONING

The latest imaging results are showing that psychopaths don't just have dysfunction in neural areas related to emotionally based traits such as aggression and impulsivity. They have trouble processing abstract concepts altogether. The next illustration shows the area of the brain where the hitch seems to occur. (For those who need a name, it's the right anterior superior temporal gyrus, which means the surface fold on the right, in the front, toward the upper part of the temples of the brain.) Here, neurons in normal individuals are more active than neurons in psychopaths when hearing abstract words such as justice. However, when concrete words such as table are heard, both normal and psychopathic brains function the same way.17 This agrees with evidence from other studies proposing that psychopathy is related to abnormalities in the right side of the brain—the artsy, abstract side that, among other tasks, synthesizes the big picture and understands nonverbal cues related to emotion.

Fig. 4.4. In the area shown, normal individuals showed much more activity than psychopaths in relation to processing abstract ideas.

The Disease of Too Much Trust—Williams Syndrome

Williams syndrome—what might be termed “antipsychopathy”—is perhaps the most endearing of all diseases. Those afflicted are very polite and sociable, show great empathy, and are completely unafraid of strangers. A trained geneticist can instantly pick out the upturned nose, wide mouth, full lips, and the long distance between the nose and the upper lip of a William's syndrome child. Such children often have heart or blood vessel problems, as well as dental and kidney abnormalities.

Fig. 4.5.

The disease is thought to be related to unusual functioning of a genetically controlled neural circuit that handles human social behavior. It is caused by the loss of a tiny snippet of roughly 21 genes on chromosome 7. In Williams syndrome patients, the amygdala, which sparks “fight-or-flight” responses, shows an unusually easygoing response to threatening faces. On the other hand, threatening scenes with no people, such as burning buildings or a plane crash, provoke overly powerful responses, meaning that Williams syndrome sufferers are uniquely “people persons” even as they are afflicted with unending phobias and worries about everything from spiders to heights. Another area, the medial prefrontal cortex, is perennially activated in Williams syndrome patients. This area, which is right behind the center of the forehead, has been associated with empathy and knowledge of how to interact socially, which may explain the heightened capabilities of Williams syndrome patients in these areas.18

It appears that the missing snippet is composed of “patterning genes” that tell the brain how to grow. Normally, as a baby's brain develops, there is a push-pull between the dorsal and ventral areas. The dorsal areas relate to mathematics, space, and recognizing the intentions of others; while the ventral areas relate to language, emotion, and social drive. Even in normal people, one area usually grows larger than the other—which is why people are often better at either math, or language, but not both. In Williams patients, however, the ventral area goes into overdrive. The excessive growth in this area directs these patients towards hyper-sociability and rich ability to process emotion, even as they are left struggling with concepts of number and space.¹⁹ It is possible that research on Williams syndrome may provide a better understanding of the overly trusting behavior of some individuals in the presence of Machiavellian and duplicitous behavior in others.

How might these and related abnormalities lead to psychopathic behavior? It may be that the difficulty psychopaths have with processing abstract concepts also means they have trouble processing complex and abstract social emotions such as love, empathy, guilt, and remorse. Therefore, it may be difficult for psychopaths to understand or control behavior involving these areas.

SEEING THE HUMAN CONSCIENCE

Modern medical imaging is showing that the human conscience, a sense of morality, and ethics—all the things psychopaths seem to be missing—aren't just the playthings of philosophers anymore. In fact, neurological regions related to morality itself have been imaged. In 2002, Brazilian researcher Jorge Moll and his colleagues published the results of a functional magnetic resonance study where people were shown pictures that normally evoke a sense of morality, such as abandoned children, physical assaults, and victims of war.b.²⁰ Scanned images of their brains after viewing these scenes were compared to images produced after viewing benign scenes and scenes that triggered disgust rather than morality. Areas activated by moral rather than everyday conditions included critical regions for social behavior and perception. Morality, in other words, involves a tangible neurological process.

Another study, by neuroscientist Scott Huettel of Duke University Medical Center, showed that more naturally altruistic people have ramped-up activity in the posterior superior temporal cortex.²¹ This is the area that is related to perceiving others’ intentions and actions. Altruism, it seems, may be founded on our understanding that others have motivations and actions that are similar to our own. Huettel explains: “Perhaps altruism did not grow out of a warm-glow feeling of doing good for others, but out of the simple recognition that that thing over there is a person that has intentions and goals. And therefore, I might want to treat them like I might want them to treat myself.”22 Yet another study showed that the emotions of guilt and shame, like feelings of altruism, activate specific areas of the brain. Shame differs from guilt by a dash of stronger activation in a few additional areas.²³ Even the processes of resentment and forgiveness appear to be related to specific sets of neural circuitry—circuitry that can go awry as psychopathology increases.²⁴

Fig. 4.6. This image, by neuroscientist Adrian Raine and his colleague Yaling Yang, highlights the overlapping areas of moral reasoning and psychopathic dysfunction.

It seems that many of the areas that are activated when a person is involved in moral reasoning overlap those that are dysfunctional in psychopaths, as shown in the preceding figure. Impairments to these areas produce impairments in the emotions that comprise the feeling of what is moral. Indeed, psychopaths know intellectually what is immoral—they just don't have a feeling of immorality about it.25

WHY DOES PSYCHOPATHY DEVELOP?

There are dazzling numbers of theories about how and why psychopathy develops, but most of them involve the idea that children with psychopathic traits have neurological glitches that reduce their moral reasoning and empathic concern for others—the emotional building blocks of conscience. Children with the callous, unemotional traits of psychopathy, along with youth who show the chronic misbehavior of conduct disorder (which has been linked to the development of antisocial personality disorder as the child grows into adulthood), often show additional traits of impulsiveness and narcissism. Such children aren't bothered by the hurtful and even shocking effects of their behavior on others and are less able to recognize expressions of sadness on the faces and in the voices of other children.²⁶ Forensic psychologist J. Reid Meloy relays the heartbreaking story of a mother of a psychopath that captures the early onset of the disorder's essence:

“At 18 months [said the mother], it was as if a switch had gone off in him. He started showing tremendous rage, complete lack of remorse and an almost complete lack of empathy. His first reaction, when he would see an animal, would be to kill it. He became extremely hateful and vicious.” This mother went on to describe his affective and predatory behavior toward her, including starting fires in the house, threatening her with a knife, and sticking straight pins out of the carpeting in front of her dresser, out of her pillow, and into her clothes so they would scratch her when she put them on…. As her child has grown older, sadistic behavior is more evident. Once he hanged a cat in the backyard and waited for his mother to come home to watch her reaction. She remembers seeing his pleasure at her horror, and then imitating her horror back to her.27

One particularly important theory about the cause of psychopathy has been developed by Joseph Newman, a University of Wisconsin psychologist who has spent the last twenty-five years investigating the wheres and whys of psychopathy. Where many researchers have focused on the lack of fear and other emotions present in psychopaths—hypothesizing that this leads to a psychopath's indifference to the feelings of others—Newman has pursued a very different idea. He believes that “psychopathy is essentially a type of learning disability or ‘informational processing deficit’ that makes individuals oblivious to the implications of their actions when focused on tasks that promise instant reward.”²⁸ Newman's work is also important in that it is helping us to better understand the different types of psychopathy. One fascinating implication is that psychopathy may not necessarily be related to violence. Forensic psychologists working with violent psychopaths in high-security prisons might be incensed by these ideas, but Newman points out that if you are looking at psychopaths in high-security environments, of course those psychopaths show violent characteristics. (It's a bit like the old story of looking for the keys under the streetlight because that's where the light is.) But there are also psychopaths in minimum-security prisons—these individuals show less violent characteristics. “The essence of psychopathy,” Newman notes, “is not the violence, or the forgery, or the sex crime, or the many miscellaneous minor crimes, it is the psychobiological process that diminishes regulation and behavior change.”²⁹

Overall then, rather like intelligence itself, it appears that moral reasoning is controlled by various neurological features of the brain—features that develop differently, if at all, in children with a genotype that predisposes them toward psychopathy. Just as a child needs the neurological structure of the eye to process information from the electromagnetic fields that shimmer through the air around him, a child also needs the structure of the orbitofrontal cortex and related neurological features to have a feeling of compassion. Psychopaths, it appears, may be born preprogrammed with a tendency to grow up “morally blind.”

EMPATHY AND MIRROR NEURONS

Empathy—identifying with and understanding another person—appears to be related to a distributed complex of neural units that are primed in part by mirror neurons. These neurons, believed by many to be the greatest neurological discovery of the 1990s, are triggered not only when humans perform an action but also when a person witnesses another person performing the same activity. Thus far, mirror neurons have been found in the premotor cortex and the inferior parietal cortex, and it is thought they may be located in additional areas of the human brain. It may be that these types of neurons have evolved to allow animals to understand what another animal is doing or to recognize another's action. It appears, however, that human mirror neurons are far more flexible and highly evolved than neurons found in any other animal. Dr. Marco Iacoboni, a neuroscientist who specializes in researching mirror neurons, notes:

When you see me perform an action—such as picking up a baseball—you automatically simulate the action in your own brain…. Circuits in your brain, which we do not yet entirely understand, inhibit you from moving while you simulate. But you understand my action because you have in your brain a template for that action based on your own movements…. And if you see me choke up, in emotional distress from striking out at home plate, mirror neurons in your brain simulate my distress. You automatically have empathy for me. You know how I feel because you literally feel what I am feeling.30

On the other hand, people with autism often display no firing in their mirror neurons in response to the activities of others. Researchers believe that the “broken” mirror neuron system of autistics lies at the heart of their difficulties with social interaction and lack of empathy, as well as their inability to imitate.

The role of mirror neurons in the development of psychopathy is as yet unclear, since psychopaths seem to have no difficulty comprehending the mental state of others. Psychopaths instead seem to have trouble empathizing with the emotional signals of others, particularly signals related to fearfulness and sadness.³¹ Researchers Linda Mealey and Stuart Kinner have pointed out that psychopaths may simply have trouble projecting onto others feelings they don't experience themselves. One psychopathic rapist commented on his victims: “They are frightened, right? But, you see, I don't really understand it. I've been frightened myself, and it wasn't unpleasant.”³²

SUCCESSFUL PSYCHOPATHS

What is perhaps even more disquieting than ordinary criminal psychopaths are “successful” psychopaths, as portrayed in Adrian Raine's findings. By recruiting and questioning ninety-one men from a Los Angeles temporary employment pool, Raine was able to gather a small group of subjects who could be divided into two subgroups: successful psychopaths—those who admitted committing crimes but had never been caught, and “unsuccessful” psychopaths—those who had been caught. The hippocampus, which is important in memory and spatial navigation, played a key role in the study, because this walnut-sized organ is also crucial in the ability to learn both what to do and what not to do. Raine theorized that psychopaths with hippocampal impairments would have difficulty learning the obvious (at least to everyone else) cues that would keep them out of trouble.

Sure enough, imaging results revealed that unsuccessful psychopaths had abnormal hippocampi, while successful psychopaths had normal hippocampi. A later study revealed another difference: unsuccessful psychopaths, but not successful psychopaths, had only three-quarters the usual volume of prefrontal gray matter. This area involves the part of our brain that is associated with the ability to determine good from bad; it also suppresses urges that could lead to socially unacceptable or frankly illegal outcomes.33

Another of Raine's studies, one that typifies his interwoven knowledge of neurology and the social sciences, sheds light on the structural pathology associated with habitual lying. This study also drew on recruits from temporary employment pools—the recruits were interviewed to find a group of twelve with a history of conning and manipulative behavior, as well as telling lies—for example, to obtain sickness benefits. This group was contrasted with twenty-one normal individuals and a third group of sixteen with antisocial personality disorder but no history of pathological lying. The study showed that prefrontal white matter in pathological liars was a quarter larger in volume than in normal people. Raine and his group had uncovered the startling fact that white matter in the prefrontal cortex is centrally involved in the desire to lie.

How could increased white matter contribute to a deceitful personality? Raine's doctoral student, Yaling Yang, who actually conducted the study, says: “It may just be easier for them to tell lies because the excessive white matter creates an abundance of connections among otherwise contradictory compartmentalized data.”³⁴ Interestingly, children with autism have decreased white matter accompanied by increased gray matter; autistics are also known for being less given to lying.

Robert Hare, who has studied psychopaths for more than a quarter of a century, has recently expanded his studies of criminal psychopaths to include what he calls corporate psychopaths, who are similar in concept to Raine's “successful psychopaths.” Hare and his collaborator, Paul Babiak, have developed a questionnaire to help identify these Snakes in Suits (the title of their book about their studies). Babiak points out: “The psychopath is the kind of individual that can give you the right impression, has a charming facade, can look and sound like the ideal leader, but behind this mask has a dark side. It's this dark side of the personality that lies, is deceitful, is manipulative, that bullies other people, that promotes fraud in the organization and steals the company's money.”35 Hare points out that knowing your boss is a psychopath can help you to survive: “The most important thing is to be aware,” Hare says. “Once you take that position you are in a better position to deal with them.”³⁶

The upshot of all this, of course, is that there might be a number of unincarcerated psychopaths free among us—unfeeling monsters but with the intact intelligence to avoid detection. Might this help explain why some Machiavellian individuals, like Hitler, Father Geoghan, or Saddam Hussein, were able to pass unsuspected in human social structures?

Perhaps.

My sister Carolyn's last diary entry provides food for thought: “Back to the real world after panic attack. Must ease Jack out…. He is still a good friend to have.”

Panic attack. Good friend.

These are the heartfelt words of a deeply Machiavellian woman—private thoughts, shared with no one, reflecting her internal world. Did her use of the word “friend” carry a different meaning from ordinary usage? That didn't appear to be the case, judging from her final, nearly decade-long, on-off supportive relationship with Jack. Also, the worst psychopaths are typically coldly unemotional—so how could Carolyn be suffering from a panic attack? Maybe she was a lesser, “secondary” psychopath? But some of the details didn't quite jibe. Was McHoskey not entirely correct about Machiavellians being equivalent to psychopaths?

Carolyn was definitely Machiavellian. But if she wasn't a psychopath, well, what was she? And where does that leave the understanding of a myriad of other sinister individuals—from the lowly accountant who embezzles his firm's funds, to the nurse who fakes credentials, to those who rise far higher in the socio-politico-economic food chain? Some of the successfully sinister definitely carry the traits of psychopathy, just as Robert Hare describes with his “corporate psychopaths.” But others, like Carolyn, show a more puzzling mix of both psychopathic and empathetic characteristics—her easy ability to lie, for example, was coupled with absolute adoration for her cats.

Do neurological disorders beyond psychopathy play a role, or an additional role, in their actions?

Perhaps it's time to peer into the big box my brother sent of Carolyn's belongings. I suspect it might lay the groundwork for better insight into the mind of a deeply Machiavellian—and tortured—soul.

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a.Some readers may have noticed that researcher Kent Kiehl's psychopathic subjects showed a decreased limbic metabolism while Adrian Raine's subjects showed an increased limbic metabolism. This is because Raine's subjects were murderers—not psychopaths. Additionally, Raine's study included those who may have been psychotic (as with schizophrenia), or had other disorders, while Kiehl's study participants had no history of psychosis. This means the two studies cannot be directly compared.

b.Several years before, a journal reviewer rejected one of Moll's first neuroscience papers on the topic, saying that “morality could never be a topic for neuroscience—it was for philosophy.”