Evil Genes
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fails to conform to social norms with respect to lawful behaviors as indicated by repeatedly performing acts that are grounds for arrest
deceitfulness, as indicated by repeated lying, use of aliases, or conning others for personal profit or pleasure
impulsivity or failure to plan ahead
irritability and aggressiveness, as indicated by repeated physical fights or assaults
reckless disregard for the safety of self or others
consistent irresponsibility, as indicated by repeated failure to sustain consistent work behavior or honor financial obligations
lack of remorse, as indicated by being indifferent to or rationalizing having hurt, mistreated, or stolen from another.
BUT WHAT IS A PSYCHOPATH?
First, a bit of background. As mentioned above, the DSM-IV presently lumps antisocial dysfunctional behavior under the general term “antisocial personality disorder,” and implies that the disorder is akin to psychopathy. But genetic and imaging research is beginning to provide compelling evidence that, if those with antisocial personality disorder were thought of as being at the bottom of the hole of the human race, psychopaths would form the subgroup that took out the shovel and kept digging. Psychopaths appear to be a special alien subset of humanity—glib, with shallow emotions, and completely lacking in the ability to feel guilt or remorse. They also indulge in classical antisocial behavior—stealing or violence. (Or, stealing and violence, as with the bank robber who shouted, “Nobody move!” and then, high on adrenaline, shot his still-moving partner.)
Both sociopath and psychopath are words used to indicate a person who is without the ability to feel remorse and other moral emotions, and who thus has no qualms about carrying out antisocial and criminal behavior. Sociologists generally use the word sociopath and believe that sociopathy is learned behavior, as, for example, with someone who is socialized in an antisocial subculture such as a gang. Biologists use the word psychopath and think that the behavior is an innate characteristic that cannot be changed. Psychology professionals disagree about which term to use.
Psychopaths know right from wrong—they just don't act that way. As preeminent neuroscientist Jorge Moll states: “A most astonishing characteristic of psychopaths resides in their ability to tell right from wrong. Their knowledge of how to behave appropriately, however, is only rhetorical and wields little, if any, impact on the guidance of their actions in real contexts. Psychopaths are the best example of the dissociation between knowing good and acting good.”3 Moll's work eerily provides two-millennia post hoc scientific validation for Aristotle's distinction between knowledge and moral virtue, where knowledge alone was felt to be insufficient for moral virtue. In short: knowing good does not entail doing good.4
Psychopaths are so scary that roughly a quarter of psychology professionals who meet one wind up experiencing goose bumps, hair standing up on the back of the neck, crawling skin, the “creeps” or the “willies,” or a sense of hotness or coldness. Forensic psychologist J. Reid Meloy notes: “These are all signs of a very old, biologically rooted activating system within our brains that is warning us of danger. The old fear of being prey to the predator.”5
SADISM
Often intertwined with psychopathy are notions of sadism. Sadism was slipped into the appendix of the DSM-III-R (the immediate predecessor to the current DSM-IV bible of mental disorders), but has since been excluded.6 Sadly, the disorder was excluded in part because enshrining it within the DSM-IV—thus providing official status—could provide an excuse for psychologists and lawyers to claim that sadistic torturers of women and children were not responsible for their actions. The disorder was also ostensibly excluded because there was too little research available—but the exclusion has meant that even less research has been done. At present, then, there is little hard science research involving sadism. There does appear to be a high rate of coexistence of sadism with other personality disorders, especially antisocial and narcissistic personality disorders.7 A small but compelling body of research shows that as evidence of psychopathy increases, evidence of sadism increases as well.8 Sadism also appears to possess a genetic component.9
Sadistic Personality Disorder
The old DSM-III-R diagnostic criteria for sadistic personality disorder are as follows:10
has used physical cruelty or violence for the purpose of establishing dominance in a relationship (not merely to achieve some noninterpersonal goal, such as striking someone in order to rob him or her)
humiliates or demeans people in the presence of others
has treated or disciplined someone under his or her control unusually harshly, for example, a child, student, prisoner, or patient
is amused by, or takes pleasure in, the psychological or physical suffering of others (including animals)
has lied for the purposes of harming or inflicting pain on others (not merely to achieve some other goal)
gets other people to do what he or she wants by frightening them (through intimidation or even terror)
restricts the autonomy of people with whom he or she has a close relationship, for example, will not let spouse leave the house unaccompanied or permit teenage daughter to attend social functions
is fascinated by violence, weapons, martial arts, injury, or torture
behavior detailed above has not been directed toward only one person (e.g., spouse, one child) and has not been solely for the purpose of sexual arousal.
Psychologist Robert Hare provides a wider context for the disorder:
It is important to emphasize that these characteristics can be expressed in differing ways in differing contexts. Perhaps the most obvious form are the tyrannical sadists who, in the workplace, choose their victims whom they abuse, intimidate, and humiliate in front of their colleagues; they obtain pleasure from the psychic pain and distress of those whom they subjugate. Sadists may seek and achieve social positions, which allow them to exercise control and to mete out punishment in socially sanctioned roles. They may include the judge who metes out punishment of a cruel and unusual severity, the army sergeant who brutalizes the new recruit, and the psychiatrist who misuses mental health legislation to incarcerate a patient.11
THE ROLE OF GENES AND ENVIRONMENT
But what causes some people to be antisocial, or psychopathic, or sadistic? Decades of research have shown that both genes and environment work together in a complex tango of cause. Intriguing research has shown, for example, that abused boys who happen to have genes coding for low levels of an enzyme, MAO-A, which breaks down communication molecules in the brain, have a higher tendency to become violent or criminal than other abused boys. When these children are raised in a normal environment, however, the gene doesn't appear to affect behavior. The low-coding MAO-A genes provided only a predisposition for antisocial behavior—an example of how both nature and nurture might combine to form personality as well as personality disorders.
Some genes lead more or less directly to changes in general health and personality. Inheritance of stuttering, redundant trinucleotides on chromosome 4, for example, can cause Huntington's disease—a disorder that leads to a dramatic transformation in personality followed by a devastatingly premature death. Susceptibility to schizophrenia is associated with specific genes on chromosomes 13 and 8. Bipolar disorder is affiliated with certain genes on (at a minimum) chromosomes 1, 6, 7, 10, 18, and 21. Discussion of all these chromosomes, genes, and inherited disorders raises the question—could there be a gene or set of genes that would lead directly to the behavior associated with at least some types of antisocial personality disorder or psychopathy?
THE GENETICS OF PSYCHOPATHY
The essentials of psychopathy can be seen even in this simple portrayal of a seven-year-old child: “Mark does not feel guilty if he has done something wrong, he does not show feelings or emotions, and he is rarely helpful if someone is hurt.”12
This description of Mark is the opening sentence of a fundamentally important 2005 study
, “Evidence for Substantial Genetic Risk for Psychopathy in 7-Year-Olds,” incongruously led by a delicate-featured young blonde with guileless blue eyes and the memorable name of Essi Viding. (Researchers with unusual names are always a delight for other researchers—search engines home right in on their work.) Viding has been curious about the possible genetic origins of antisocial behavior since a stint as a junior researcher before graduate school. She noticed that despite efforts from professionals, there seemed to be some antisocial children who appeared beyond reach.
Viding's study sought to tease out how much genetics comes into play in antisocial behavior in children with outright psychopathic tendencies, as well as in those with less severe forms of antisocial behavior. To do this, Viding used results from TEDS—the Twins Early Development Study—a monumental study of over five thousand pairs of twins in the United Kingdom who were born in 1994, 1995, and 1996. The TED study was initiated to allow scientists to take advantage of the fact that while identical twins share 100 percent of their genes, fraternal twins share only about 50 percent. If the effect of genes predominates for a given characteristic—extroversion, for example—then you would expect that if one identical twin was outgoing, the other one would be too. But for fraternal twins, like my husband and his sister, it is just as likely that one could be laconic (my husband), while the other is loquacious (Jane),
The effect of environment turns out to have two components. One component has to do with the environment the twins share: a set of easygoing, loving parents, for example, or a shared diet of lard-ridden Southern cooking. You can figure out what this shared environment is by playing with the data to see if fraternal twins appear to be more similar than expected, since they share only half their genes.
The other environmental component has to do with a nonshared environment. Maybe Mom really did like your twin best, or maybe your stepfather decided you were the one he was going to beat when he had too much to drink. You can get an idea of what this nonshared environment is by looking at the data from identical twins. If the twins aren't 100 percent identical for a certain trait, the nonshared environment is suspected to be the reason.
Viding's group surveyed the teachers of 3,687 pairs of “TEDS” twins from the 1994 and 1995 births regarding their students’ character traits. From this, 187 pairs of twins were found to have at least one twin who displayed extreme psychopathic traits. In another 177 pairs of twins, at least one of the twins was found to display traits of antisocial behavior but without the callous, emotionless features of psychopathy.
By careful analysis of the data for identical versus fraternal twins, what Viding found was unexpected—and striking. Antisocial behavior in those twins who were highly psychopathic was under strong genetic influence—a heritability of 81 percent.a.13 The remaining 19 percent of influence appeared to be entirely due to unshared environmental components—differences in how the two twins were raised. The twins with antisocial behavior, on the other hand, showed a moderate genetic heritability of 30 percent; the remaining influences were entirely environmental.14
If this seems hard to swallow, here's an analogy. Let's say that you randomly gather a group of older children of normal intelligence who are poor readers. If you analyze the group carefully, you might find that some kids have a poor home environment or have disadvantaged schooling. Based on the twin studies, you would probably find that there was also evidence of a slight genetic component.
Fig. 2.1.
But now let's say you asked your poor readers to read and answer the simple question: “Do the words fruit and boot rhyme?” You'd find that the kids would automatically sort themselves into two groups, irrespective of schooling. One group of kids would answer the question easily, while the other group would struggle. If you then analyzed each of these groups separately by drawing on the twin studies, you would find something very different from your first analysis. The children who easily understood that fruit and boot rhyme would probably show that their reading ability was substantially influenced by their environment. But the group who had trouble seeing the rhyme would probably show considerable genetic evidence for their reading disability. This is because some or many of the children who had trouble with the unusual rhyming pattern were probably dyslexic, and dyslexia has a strong genetic component.
Let's look again at the results from the study of psychopathy. Discarding the belief in the natural innocence of children and eliminating a century of social engineering, this means that some kids are born with a marked tendency toward evil. Sure, traditional forms of intervening in the family environment seem to work for kids with a light set of antisocial genes. But some type of genetic vulnerability appears to cause significant differences in the neurological development of children with psychopathic tendencies. As Viding had seen at the very beginning of her academic career, these unusual children seem remarkably resistant to intervention and may be at high risk for becoming adult psychopaths. Viding's study has far-reaching implications for treatment and prevention—precisely the reason she carried out the research. For, if the cause of psychopathy is indeed genetic—that is, related to subcellular programming—an understanding of that programming can lead to methods of repair.
But what exactly is going on, genetically speaking, in those with problematic personalities? We have finally reached a new, genomic era, where we can begin to understand.
And perhaps, just perhaps, I can find some clues about Carolyn.
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a.This might bring some readers to wonder about identical twins pairs in which one twin has psychopathic traits and one does not. Remember—just having the genetics for a disorder does not necessarily mean the disorder is inevitable. It may mean, for example, that one twin is just over the diagnosable edge, while the other isn't. Even with identical twins growing up in the same environment, it's impossible to identically wire brains with 100 trillion synapses. And environment itself does make a difference. For example, phenylketonuria, a recessive single-gene disorder, causes severe mental retardation. However, administering a diet low on phenylalanine prevents mental retardation. Judith Rich Harris's latest book, No Two Alike, provides an elegant hypothesis related to the often troublesome category of “non-shared environment.”
Perhaps more importantly, the idea that the variation in personalities is roughly half due to genetics and half to environment is valid, but misleading. Psychopaths, for example, sometimes appear to possess “dominant” sets of genes that override the influence of environment.
“The problem with the gene pool is there aren't any lifeguards.”
—Anonymous
We already know that genes have dramatic effects on virtually every aspect of the human body—height, weight, skin color, and even the ability to process oxygen. But sometimes we forget how important genes are in shaping personality. As behavioral geneticist Robert Plomin has pointed out, the answer to the question “how much does heredity affect behavior” is “a lot.”1 Indeed, as Plomin notes, genetic influence is so ubiquitous that we should not be asking what is heritable with regard to behavior. Instead, we should be asking what is not heritable. “So far,” he notes, “the only domain that shows little or no genetic influence involves beliefs such as religiosity and political values; another possibility is creativity independent of IQ.”a.2
Recent research has even undermined the long-held belief that troubled, argumentative marriages cause problematic behavior in the children brought up in those households. A recent study of adult twins and their offspring revealed that it is not the family discord that causes problematic behavior but rather the genes that troubled parents pass along. In fact, the parents’ own genes apparently determine how often they argue with each other.3
Ultimately, then, since genes are so crucially important to understanding personality—including its Machiavellian manifestations—it's a good idea to take a quick review of some fundamentals. A human body is composed of about a trillion tiny, membrane-enclosed cells—bone cells, nerve c
ells, white blood cells, and so on. Each cell is alive and carries out its own suite of “life functions” by following the instructions encoded in its genes. The genes are portions of chromosomes, sequestered in the cell's spherical nucleus. Most human cells (there are a few exceptions) contain forty-six chromosomes—twenty-three inherited from the mother, and another twenty-three from the father. Each chromosome is a long, slender DNA molecule. If all the DNA in one cell's chromosomes were stretched out, they would total about six feet in length. That means that the average chromosome is a couple of inches long—which makes a DNA strand a giant, as molecules go. But because DNA is extraordinarily slender—thousands of times thinner than a hair—all forty-six human chromosomes are easily wadded up like a molecular-sized ball of string inside the cell's nucleus.
Fig. 3.1. The 46 human chromosomes
DNA molecules are not only long and skinny but also very simple in structure. The famous DNA “double helix” consists of two parallel (but twisted) chains of molecular building blocks called nucleotides. There are only four kinds of nucleotides, and what makes the four different from one another are parts of the nucleotides called bases—adenine, guanine, thymine, and cytosine. The four DNA bases are almost always abbreviated A, G, T, and C. The DNA “code” consists of sequences of nucleotides with various bases. ATTCGACCTCC tells a cell to do one thing, TGACCTGCAG says something else. You can think of a cell's chromosomes as a set of cookbooks, with each chromosome being a volume, and each gene a recipe. There are hundreds of gene “recipes” strung along each chromosome, and roughly 70 percent of all those genes participate in the development and operation of our brain.