Savage Spawn (7 page)

VIII

The Biology of Being Bad

During our discussion of environmental factors, biology has crept in often, because, as noted, the distinction between nature and nurture is artificial. Nevertheless, a number of studies do exist that have attempted to isolate organic variables, and they deserve attention.

Biological explanations for psychopathic (and all types of deviant) behavior are frightening, because biological determinism seems to fly in the face of concepts such as free will and social rehabilitation, and it raises the terrifying specter of the immutable “bad seed.”

More important, serious abuses of biological determinism have been frequent and nightmarish, leading to such repellent outrages as eugenics—the pseudoscience of “cleansing” the human race through selective breeding, developed by the brilliant but misguided (and sterile) nineteenth-century British mathematician Francis Galton—and its philosophical offspring: forced sterilization, euthanasia, and genocide. Genetic dominance of intelligence and other traits has long been a pet cause of xenophobes and racists. The Nazi Holocaust had its roots in eugenics theory.

Another risk when evaluating biological research is the intellectual seductiveness of apparently hard science. It is easy to overvalue studies crammed with chemical compounds, graphs, and equations because they appear to offer authoritative, relatively clear-cut answers to complex questions, especially when compared to the fuzzy conundrums produced by social science research. But what looks like incontrovertible science often turns out to be no more than supposition and guesswork overlaid with a veneer of quantitative data. Just as is true of its softer cousin, “hard” science is profoundly vulnerable to the value judgments and prejudices of its all-too-fallible practitioners. The same methodological problems that often scrape the blush from the first fruits of social science data can apply equally to biological studies. Cautions such as our old friend
Correlation ain't necessarily causation
are just as valid.

Nevertheless, nearly five decades of research on the biological aspects of psychopathy and criminality have produced some provocative data that deserve to be addressed.

And though we must examine biological data critically, we needn't be scared off by some brave-new-world threat of genetic determinism, because while some biological phenomena are genetically based,
many others are not.

In fact, the distinction between genetics and biology is a prime example of the correlation/causation caveat appropriately applied: Simply because something manifests itself on a cellular, hormonal, or biochemical level does not mean its
origins
are based in inborn cellular, hormonal, or biochemical processes.

Put simply, biology modifies environment, but environment also modifies biology.

Consider the example of identical (monozygotic) twins—pairs of siblings endowed with identical DNA. Most identical twins resemble each other strongly, yet individual sets of twins differ greatly in their degree of identicality. Some are almost completely identical, while others display significant physical and behavioral differences. Most important,
no identical twins are absolute carbon copies of each other.

I am personally familiar with identical twins, young women, one of whom is two inches taller than her sister. Height is to a great extent determined by genes, but even here the causal pathway is clearly not 100 percent genetic.

What nongenetic (but biological) factors might have played a role in the two-inch discrepancy? Perhaps as fetuses these women underwent specific intrauterine experiences that affected their respective heights, with one twin lucking into a superior position within the womb—a literal upper hand—that provided her with the lion's share of placental nutrition and movement, simultaneously restricting her sibling's snacks and aerobic exercise. Or maybe postnatal experiences, such as illness and injury, intervened.

We needn't limit ourselves to twins when searching for examples of the discontinuity between biological and genetic causality. Average heights and weights of Japanese citizens and those of other developing nations increased significantly following World War II, due to changes in nutrition.

With regard to children, a variety of prenatal insults that have nothing to do with chromosomes can strongly affect growth and subsequent development. Youngsters exposed to maternal malnutrition and injury, as well as to alcohol, tobacco, and other toxins, are more likely to evince brain damage, birth defects, learning problems—and antisocial behavior—than are nonpoisoned controls. The same goes for birth complications, prematurity, and postnatal damage, such as poisoning by lead chips in old paint, head trauma, infections, and recurrent fevers.

Several studies of child and adult murderers indicate high rates of brain damage as measured by learning disabilities, attention deficit, school problems, EEG (brain wave) measurement, and low IQ, but whether or not any of these deficits is genetic is unclear (9–13, 46). In some cases, such as documented episodes of cranial injury, they certainly are not. And given strong evidence that many psychopaths and criminals are more likely to be abused, it's not much of a stretch to connect early maltreatment, such as kicks to the head, to environmentally caused brain damage.

Before we jump on brain damage as a defense, however, it's important to realize that the data on cerebral pathology and adult criminality are suggestive but not close to definitive. Some studies of psychopathic criminals have failed to produce strong evidence of brain abnormality (47). Nevertheless, a host of information does seem to indicate consistent differences between psychopaths and normal people that point to some kind of biological irregularity, possibly in the anterior (front) part of the brain, a region implicated in the regulation of emotion, reasoning, and social aggression.

Most conspicuously, psychopaths appear to exhibit
lower physiological arousal
than do normal individuals. This fits with the long-documented observation that psychopathic criminals fail to display fear and anxiety in situations that upset normal people, and seem to have great difficulty learning from unpleasant experiences. They also appear to be underresponsive to emotional stimuli in general. The notion of the stone-cold killer is based in reality (48, 49).

Some specific examples: When a sample of emotionally disturbed adolescents in treatment was divided on the basis of sleep patterns, the poor sleepers were more likely to be neurotic, while the sound sleepers tended to be psychopathic (15). A study of the level of stress hormone in the urine of arrested men showed increased secretion in nonpsychopaths as trial date approached, but no such pattern in psychopaths (22). Psychopaths have consistently shown lack of fear when exposed to frightening stimuli, though, as noted, they are quite vigilant about sensing threat and responding with anger (21). Most troubling is that these tendencies show themselves during early childhood.

Two theories have attempted to explain the connection between a cold nervous system and criminality. The first,
disinhibition,
emphasizes fearlessness. Relatively unburdened by anxiety, the psychopath fails to respond to the threat of punishment and engages in risky behaviors that draw him into antisocial activities. And indeed, psychopaths often do act in an eerily calm, unflustered manner when doing things that would terrify and shock the rest of us. Ted Bundy continued to smile, mug for the cameras, and lie convincingly throughout his arrest, imprisonment, and trial, with the mask beginning to crack only as execution drew near.

Strikingly realistic depictions of the blithe psychopath can be found more readily in fiction than in the psychiatric literature, with writers such as Elmore Leonard, Jim Thompson, Ruth Rendell, Charles Willeford, and my wife, Faye Kellerman (check out her novel
Justice
), capturing this persona with astonishing clarity. Lou Ford, Thompson's glib, emotionally flat, and pseudoinnocent sheriff protagonist of
The Killer Inside Me
, may very well be
the
perfect portrait of unruffled evil.

The second approach to underreactivity,
sensation seeking
, posits that chronically low levels of brain stimulation cause the psychopath to embark on a constant search for thrills. And indeed, psychopaths often do display very low thresholds for boredom, as well as high rates of alcohol and drug abuse that can be viewed as intense sensation-seeking behavior, or even self-medication for chronic mental emptiness.

The variables most commonly used to quantify arousability as it relates to antisocial behavior have been heart rate, skin conductance (the level of electrical activity passing along the skin, often related to perspiration), and brain wave patterns. Ironically, the first two are also components of the polygraph, the so-called lie detector—an apparatus whose practical value is based upon the premise that uttering falsehoods produces bodily arousal. But if psychopaths are indeed
less
arousable than normal people, they could be expected to beat the machine at higher rates than the rest of us. Furthermore, if there is a direct relationship between degree of psychopathy and “coolness”—the more psychopathic, the less flappable—then those criminals most likely to render the polygraph useless may very well be the most pathological and dangerous liars.

The findings of arousability research are anything but clear-cut. Skin conductance studies have produced inconsistent results: Some researchers have found a relationship between psychopathy and low skin conductance; others have not (50). Fogging the matter further, no consistent relationship has been found between skin conductance and criminality per se. So if a link between skin conductance and deviance does exist, it appears to explain only antisocial
tendencies
rather than the actual
commission
of misdeeds.

Brain wave research, as noted, has produced mixed results in the opposite direction. There is plenty of evidence that institutionalized criminals—children, adolescents, and adults—display higher rates of learning and attentional problems as well as EEG abnormality (though EEG findings are notoriously difficult to interpret), but no consistent irregularities have been identified in psychopaths (9–13, 51, 52).

Heart rate appears somewhat more promising. Numerous studies have shown that antisocial individuals exhibit significantly lower cardiac arousability than do normal persons, as measured by relatively low resting heart rates as well as cardiac systems that fail to respond strongly to threatening situations (50, 53). Heart rate, as Adrian Raine, the most prolific researcher in this area, has stated, is the “strongest and best replicated finding in the field of the psychophysiology of anti-social behavior”(50). However, once again, as Raine himself points out, the link seems to be to psychopathy, not criminality. Prisons are full of people with normal and hyperactive nervous systems.

Part of the problem may be that most heart rate research has been retrospective—selecting a sample of adult psychopaths or criminals and measuring their arousability. This tells us nothing about any developmental or causal process, nor does it control for confounding factors. For example, we know that heart rate decreases steadily throughout childhood, reaching its low point around the age of twenty, before reversing and commencing a gradual rise that may continue throughout adulthood. So perhaps studies of grown-up criminals have missed the boat. Certainly research that doesn't take age into account should be considered questionable.

In response to these problems, Raine and his colleagues, as well as others, have carried out
prospective
studies, measuring cardiac arousability in very young children and following these youngsters into adolescence and adulthood (54–56). This work was conducted in countries with well-established, centralized systems of socialized medicine that allowed access to large-scale data banks, primarily Scandinavia and the United Kingdom, as well as in isolated, easily studied communities such as the tiny Indian Ocean island of Mauritius. So cultural differences may limit the relevance of these studies to American society. But their results are striking and deserve more than casual attention.

The Mauritius Child Health Study, conducted by Raine and his associates, is especially noteworthy because every child on the island born in 1969 was studied at the age of three, providing a sample of 1,795 (later reduced to 1,130 after a cyclone destroyed many of the island's homes) (54). Heart rate was studied and measures of psychological adjustment were taken eight years later. The basic finding was that low resting cardiac rate in toddlers predicted aggressiveness and antisocial tendencies at a better-than-chance level even when environmental factors, such as social deprivation and broken homes, and biological factors, such as body size, activity level, physical development, muscle tone, and general health, were controlled for.

Research carried out by Raine also approached the issue from the opposite end, suggesting the protective nature of arousability. In these studies, youngsters at high risk for criminality because they had criminal fathers were more likely to
avoid
crime if their resting heart rates during childhood were high. Fear, it appears, can be a highly effective teacher (55–57).

Nevertheless, these findings lead us to the same kinds of problems we faced when assessing environmental variables: Assuming a link exists between cardiac activity and antisocial behavior,
how important is it and what does it mean?
A better-than-chance prediction rate may be fine when submitting a paper or playing blackjack, but what practical ramifications does it have for the amelioration of childhood violence? Is anyone suggesting that we segregate preschool kids simply on the basis of low heart rates, offering them antidelinquency training because of their EKG profiles? Even if this were socially acceptable or feasible, it wouldn't be wise because we'd be wasting plenty of time preaching to kids who didn't need it while failing to detect a good number of criminals-in-training. Heart rate studies reveal plenty of boys with normal heart rates who subsequently become aggressive, antisocial, even criminal, as well as low-heart-rate kids who don't turn bad.