The Psychopath Inside: A Neuroscientist's Personal Journey into the Dark Side of the Brain

“People with autism lack theory of mind but not empathy, while people with psychopathy lack empathy but not theory of mind. Without empathy you can still have sympathy, though—the ability to retrieve emotional memories, including those that can predict what painful event is probably about to befall another person, and the will to help that person.”

“Despite the controversy over whether psychopaths exist, psychiatrists generally agree that one of the defining characteristics of those we refer to as psychopaths is the lack of interpersonal empathy, what one might call a flat emotional playing field. Psychopaths may not hate, but they also may not love the way most of us would prefer to love and be loved. Psychopaths are usually manipulative, are champion liars, and can be quite glib and disarmingly charming. They don’t fear consequences the way most people do, and while they may react to the stress of being caught in a lie or violent act like anyone would, some remain cool as cucumbers. Even the most dangerous can appear jovial, carefree, and social at times, but sooner or later they will display a telling distance, a quiet coldheartedness and disregard for others. They are often impulsive, yet lack guilt and remorse, meaning they may invite you to join in on their reckless, even dangerous fun, and then shrug their shoulders if someone gets hurt.”

“After a murder, psychopaths often say they feel like someone else did it, or the victim precipitated the pulling of the trigger. They feel detached, impelled to action by forces out of their control.”

“how we think of free will. While we all think that we first plan our actions and that they are then willfully carried out, in some cases a part of our frontal lobe may actually “decide” first, unconsciously, that we will perform an act, and after we carry out the act we fool ourselves into thinking we planned it.”

“The traits can be sorted into four different categories, or “factors.” The interpersonal factor includes the traits of superficiality, grandiosity, and deceitfulness. The affective factor includes lack of remorse, lack of empathy, and refusal to accept responsibility for one’s actions. The behavioral factor includes impulsivity, lack of goals, and unreliability. And the antisocial factor includes hotheadedness, a history of juvenile delinquency, and a criminal record. Antisocial personality disorder is related to psychopathy but is much more common and is a measure of outward disruptive behavior rather than an underlying personality problem. Psychopathy scores are actually a better predictor of criminal recidivism, severity, and premeditation”

“As a neuroscientist well into the fourth decade of my career, I’d looked at a lot of brain scans over the years, and these had been different. The brains belonging to these killers shared a rare and alarming pattern of low brain function in certain parts of the frontal and temporal lobes—areas commonly associated with self-control and empathy. This makes sense for those with a history of inhuman violence, since the reduction of activity in these regions suggests a lack of a normal sense of moral reasoning and of the ability to inhibit their impulses.”

“A psychopath has a poorly functioning ventral system, usually used for hot cognition, but he can have a normal or even supernormal dorsal system, so that without the bother of conscience and empathy, the cold planning and execution of predatory behaviors becomes finely tuned, convincing, highly manipulative, and formidable. Because psychopaths’ dorsal systems work so well, they can learn how to appear that they care, thus making them even more dangerous.”

“Although there are no set methods to test for psychiatric disorders like psychopathy, we can determine some facets of a patient’s mental state by studying his brain with imaging techniques like PET (positron emission tomography) and fMRI (functional magnetic resonance imaging) scanning, as well as genetics, behavioral and psychometric testing, and other pieces of information gathered from a full medical and psychiatric workup. Taken together, these tests can reveal symptoms that might indicate a psychiatric disorder. Since psychiatric disorders are often characterized by more than one symptom, a patient will be diagnosed based on the number and severity of various symptoms. For most disorders, a diagnosis is also classified on a sliding scale—more often called a spectrum—that indicates whether the patient’s case is mild, moderate, or severe. The most common spectrum associated with such disorders is the autism spectrum. At the low end are delayed language learning and narrow interests, and at the high end are strongly repetitive behaviors and an inability to communicate.”

“Robert Hare has pointed out that sociologists are more likely to focus on the environmental or socially modifiable facets of the disorder, so prefer the term sociopathy, whereas psychologists and psychiatrists prefer to include the genetic, cognitive, and emotional factors as well as the social factors when making a diagnosis, and therefore would opt for psychopathy.”

“In impulsive people there is often a malfunctioning of the orbital cortex, and in hypersexual and rage-prone people there is often amygdaloid dysfunction. In people with parahippocampal and amygdala damage, one often finds inadequacies in emotional memory, sexuality, and social behavior, and in people with cingulate dysfunction, there can be problems with mood regulation and behavioral control. But the pattern of decreased functioning across the entire complex of these limbic, prefrontal, and temporal cortices—whether due to prenatal development, perinatal maternal stress, substance abuse, direct trauma, or a severe rare combination of “high-risk” genes—appeared unique to the psychopath’s brain.”

“A PET (positron emission tomography) scan is a tool used in radiology to determine the functioning of the body, specifically small areas the size of a grain of sand in tissues and organs. It is particularly useful in looking into organs, such as the brain, that are encased in bone. The PET scan is considered a functional rather than merely structural scan because it measures the functioning of the brain. Radioactive molecules that interact with the brain in specific ways are injected before the scan. They can be sugars, to measure the brain’s metabolism, or drugs that link to the receptors for various neurotransmitters, to measure the distribution of those receptors.”

“Even Patrick Bateman, Christian Bale’s self-loving, unhinged character in the film adaptation of American Psycho, is not representative of a true psychopath, as he is too violent to be realistic. These are caricatures—even the most violent criminals are rarely so obviously insane.”

“These brain circuits mature at different times during development, and although there are major maturational events that take place in the terrible twos, puberty, late adolescence, the twenties, and the mid-thirties, some are not completely integrated until one is in the sixties, which appears to be the typical average peak time of human insight, cognition, and understanding in many realms of life.”

“The anterior, or front, section is the prefrontal cortex and is responsible for the so-called executive functions of the brain, including knowing rules, making plans, and enabling short-term memory. This “scratch pad” memory lasts seconds or tens of seconds and helps us to remember phone numbers long enough to dial them and tells us, without looking, where we set our drink while we’re eating or playing poker. The prefrontal cortex is the brain region most important for the elaboration of personality and character, and the control of impulse, obsessions, and antisocial behavior.”

“I need to see my innocent teasing and practical jokes for the hurt that they can cause. Even though unintentionally bothersome, these behaviors fringe on sadism, the more I look at them and their effects on the happiness of others.”

“I haven’t heard a lot of Libertarians admit to these views, but if pressed I’m sure many would agree. For me, by sticking to the basic principles of the Constitution—fairness, private property, and so on—I know some people will die, but it doesn’t bother me. If the system weeds out weak or lazy individuals, fine. I don’t want to encourage unproductive or irresponsible behavior because I think it will kill society. I’m more sympathetic to the species than I am to that one person or group of people.”

“The external world—up, down, left, right, close up, far away—is mapped onto the cortex in the upper part of the posterior area, called the superior parietal cortex. People with damage to this brain area on one side will ignore the other half of their sensory world. So they may only perceive the numbers on the left side of a clock dial, but not the right side. Given a blank circle, they will fill in the numbers on the dial from 1 to 12, but these will all be drawn on just one half of the clock. If the damage is done to the hemisphere that controls their nondominant hand, let’s say the right superior parietal cortex for a right-hander (each hemisphere controls the opposite side of the body), then they will go the extra step in their “agnosia.” They will be able to move the opposite leg, and feel a pinch on that leg, but they may ask the doctor or nurse to remove the leg from the hospital bed because it is foreign and doesn’t belong to their body.”

“To better understand exactly what I saw in these scans and why it was so relevant, you first need to have a basic understanding of the human brain. The brain is organized in a bewildering number of ways, even to a silverback neuroscientist. The researcher Floyd Bloom once called it an “electrified jelly,” which is certainly what it seems like to a first-year medical student. Neuroanatomists categorize themselves into “clumpers” and “splitters” based on how they like to organize the brain. Clumpers prefer to simplify the brain into as few sections as possible, while splitters divide the brain into thousands of pieces, all with their own Latin or Greek names. To make things even more confusing, splitters like to throw into the mix the name of the scientist who first described that brain area, so we end up with names like “Zuckerkandl’s fasciculus,” “the ventral tegmental relay zone of Giolli,” and the “nucleus reticularis tegmenti pontis of Bechterew.” This is one of the reasons medical students are terrified of their first course in neuroscience. When these brain areas, their connections, chemistry, and circuitry, are considered together for any adaptive behavior, for example an infant expressing fear at the sight of a stranger, the complexity of the brain’s wiring can start to get out of hand. For clinical sciences the representation of the relevant wiring of the brain can quickly send one packing to the nearest pub for a cold one.”

“real nurture can overcome a lousy deck of cards dealt at birth by nature.”

“Sequences of base pairs, called genes, code for and produce gene products such as proteins. If just one of the base pairs is altered by mutation, say from ultraviolet damage, a virus, or cigarette smoke, the resulting protein will be aberrant, and usually faulty. Some of these mutations are not fatal and are actually kept by the cells and the population. These are called single nucleotide polymorphisms, or SNPs. If the incidence of the change is found in less than 1 percent of the population of humans, it is called a mutation; if more than 1 percent, it is typically called an SNP. There are about twenty million SNPs found in humans, and they account for many differences in the appearance and behavior of people, from curly hair to obesity to drug addiction. It is these SNPs where the hunt for genetic “causes” of traits and diseases has focused since the 1990s.”

“But during the first five hundred panic attacks, I was certain that I was going to die within a minute or two. I would get these anytime, day or night, and it didn’t matter if I was alone or in a crowd. It would just happen. It did not matter that I knew full well I would not die, having experienced these attacks before. The limbic system convinced the rest of my brain that I was about to kick the bucket.”

“The monoamine neurotransmitters, or modulators, as they are often called, are like volume buttons in the brain. Neurons “talk” to each other by releasing tiny molecules called neurotransmitters into clefts between them called synapses. The signaling neuron releases a packet of transmitters, which can then lock into receptors on the receiving neuron, altering that neuron’s behavior. Then the transmitters are broken down or transported back inside the signaling neuron. The two most important neurotransmitters are glutamate and GABA. Glutamate is excitatory, meaning that when it’s released and encounters a receptor, it encourages that second neuron to “fire” and send its own neurotransmitters to still more neurons. GABA is the chief inhibitory neurotransmitter, meaning that it tells neurons not to fire. Without it, the brain would go haywire.”

“Other important alterations to the genetic code involve so-called promoters and inhibitors, pieces of genes that regulate the gene’s ability to make products. Some of these products regulate the behavior of neurotransmitters. So promoters and inhibitors are like the gas and brake pedals of a gene as they control the delivery of neurotransmitters like serotonin and dopamine in the brain. For serotonin, implicated in depression, bipolar disorder, sleep and eating disorders, schizophrenia, hallucinations and panic attacks, as well as psychopathy, the breakdown enzyme is MAO-A. MAOA, the gene that produces this enzyme (and lacks its hyphen), has a promoter that comes in either a short form or a long form. The version of the MAOA gene with the short promoter has been associated with aggressive behavior and is called the “warrior gene.”

“Neuroanatomists categorize themselves into “clumpers” and “splitters” based on how they like to organize the brain. Clumpers prefer to simplify the brain into as few sections as possible, while splitters divide the brain into thousands of pieces, all with their own Latin or Greek names. To make things even more confusing, splitters like to throw into the mix the name of the scientist who first described that brain area, so we end up with names like “Zuckerkandl’s fasciculus,” “the ventral tegmental relay zone of Giolli,” and the “nucleus reticularis tegmenti pontis of Bechterew.”

“For one thing, psychiatric diseases are not considered diseases at all. Diseases are based onknowledge of the cause (or etiology) of a particular disorder and the effects (or pathophysiology) they have on the body. Unlike for many true diseases of other organ systems, we don’t have this luxury with diseases of the mind since so little is known of the underlying pathological biological mechanisms at work. Despite advances in our understanding of how the brain works, the organ is still largely a mystery to us. Therefore, most psychiatric problems are called disorders or syndromes. Psychopathy stands on the lowest rung of this disease-disorder ladder, since no one agrees on what defines it—or if it exists at all— and so there is no professional agreement as to the underlying causes.”