The Anatomy of Violence (35 page)

Relative finger length, then, provides us a window backward in time to view what occurred during fetal development. It suggests not only that
Lombroso was partly correct, but also that the pre-birth period is more important than we have previously thought. Of course, mothers cannot control their hormone levels during pregnancy—they are not in any way to blame if their child is exposed to higher testosterone and becomes aggressive later in life. But there are other things she knowingly does that will shape the fate of her child in a negative direction.

Smoking is not good for your health. But it can do wonders for your violence potential, especially if your mother smoked like a chimney while she was pregnant with you. We now know that if a mother smokes during pregnancy it not only has negative consequences on brain development, but it also leads to increased rates of
conduct disorder and aggression in her offspring. A spate of studies has established beyond a reasonable doubt a significant link between smoking during pregnancy and both later conduct disorder in children and violent offending in
adults. A number of these studies are impressive in terms of their size, the prospective nature of data collection, long-term outcome, and control for third factors, suggesting that the relationship is causal.

Using the
birth cohort from Denmark that included 4,169 males, the psychologist
Patty Brennan at
Emory University found a twofold increase in adult violent offending in the offspring of
mothers who smoked twenty cigarettes a day.
⁷⁷
She also found a dose-response relationship, with an increase in the number of cigarettes smoked resulting in a linear increase in adult violence. It was an impressive study, and there are many others like it in different countries.

In one birth cohort of 5,966 from
Finland, the offspring of mothers who smoked were twice as likely to have a criminal record by age twenty-two.
⁷⁸
In a follow-up study of this Finnish sample to age twenty-six, a twofold increase in violent crime and repeat offending was found in the offspring of mothers who smoked.
⁷⁹
In the United States, boys of mothers who smoked ten cigarettes a day during pregnancy were four times more likely to have conduct disorder.
⁸⁰

These samples are predominantly Caucasian—are the same effects found for other ethnic groups? They do seem to hold for
African-Americans, at least. The same effect of
prenatal smoking exposure in increasing both conduct disorder
⁸¹
and disruptive behavior problems
⁸²
has been observed in African-American children. One U.S. study showed more than a fourfold increase in conduct disorder in the offspring of mothers who smoked half a pack of cigarettes a day,
⁸³
and another found an increase of six points in behavior problems in three-year-olds exposed to smoking during the third trimester.
⁸⁴
In
New Zealand, a doubling in the rate of conduct disorder was found in the offspring of maternal smokers.
⁸⁵
You find the same relationship between prenatal smoking and antisocial behavior in Welsh children and adolescents.
⁸⁶
Wherever you go in the world, you get the same finding.

Of course, you’ve probably already asked yourself a very good question: Could it be that mothers who smoke during pregnancy are not, on average, the most caring, educated, empathic, and informed parents in the world? Someone willing to subject her unborn child to toxins in the womb may not be providing the best environment after a child is born. To illustrate this point further, in one study a full 72 percent of the offspring of mothers who smoked during pregnancy had experienced either physical or
sexual abuse. In addressing this important issue many of the studies have taken pains to control for third
factors that could account for the
smoking-antisocial relationship. But even then, crime and antisocial personality in the parents, low socioeconomic status, low maternal educational level, mother’s age at the child’s birth, family size, poor child-rearing behaviors, bad parenting, obstetric complications, birth weight, family problems, parental psychiatric diagnoses, attention-deficit/hyperactivity disorder, offspring smoking, and other drug use during pregnancy could not account for the relationship. After that shopping list of confounds, there’s not a lot left to control for. Taken together with the dose-response relationship that was also established in several of the studies, these findings appear to be real, and suggest a causal relationship between smoking during pregnancy and later violence.
⁸⁷

Every puff counts. Studies repeatedly show that the more cigarettes the mother smokes, the greater the odds of antisocial behavior in her offspring. We’ll also see later in the book that many other factors combine together with maternal prenatal smoking to really boost the odds of violence in their offspring.

It’s my hope that if you are reading this and you are pregnant you will decide to quit for the good of your little one. But I should warn you that this alone may not be enough. If your husband or co-workers smoke, you are still exposing your baby to the toxic effects of smoking.
Lisa Gatzke-Kopp, at Penn State University and a past graduate student of mine, found that
secondhand
exposure to cigarette smoking predicted conduct disorder even after controlling for antisocial behavior in the parents, poor parenting practices, and other biological and social confounds.
⁸⁸

How can a few puffs during pregnancy
cause
the fetus to become a fighter later in life? What is the nature of the causal path from
fetal nicotine exposure to antisocial behavior? First and foremost, it can partly account for the brain deficits that we saw to be apparent in brain scans of adult offenders. Animal research has clearly demonstrated the neurotoxic effects of two constituents of cigarette smoke—carbon monoxide and nicotine.
⁸⁹
Nicotine passes across the
placenta, directly exposing the fetus. A primary effect is that it reduces uterine blood flow and consequently reduces both nutrients and oxygen to the fetus, producing
hypoxia, which can damage the brain. Babies exposed to smoking have been shown to have a reduction in head circumference, indirectly reflecting a reduction in brain development.
⁹⁰
Studies
of brain-scanned adults who were exposed as a fetus to maternal smoking show that
they have thinner orbitofrontal and
middle frontal gyral thickness—brain areas that we will see in a later chapter are especially implicated in violence.
⁹¹

Because smoking negatively affects the fetal brain, we would expect such exposed infants to show neuropsychological impairments later on in childhood and adolescence—and they do. Studies have documented impairments in selective
attention,
memory, and speed in processing speech stimuli.
⁹²
A dose-response relationship between increased cigarette smoking and reductions in arithmetic and spelling between ages six and eleven has been reported.
⁹³
We’ve seen that neurocognitive functions are impaired in offenders, and we also know that such offenders fail in school, where math and spelling abilities are important. Fetal exposure to smoking is a likely contribution to this neurocognitive pathway to antisocial and violent behavior.

Prenatal
nicotine exposure, even at relatively
low levels, disrupts the development of the
noradrenergic neurotransmitter system.
⁹⁴
This is of particular significance in the context of the
autonomic deficits we discussed earlier. Reduction of noradrenergic functioning caused by smoking would be expected to disrupt sympathetic nervous system activity. As we saw earlier, reduced sympathetic arousal as measured by
sweat rate has been found in antisocial individuals. Furthermore, when pregnant rats are exposed to nicotine at the levels commonly found in human smokers, the offspring show an enhancement of
cardiac M2-muscarinic cholinergic receptors. These receptors
inhibit
autonomic functions,
⁹⁵
so stimulation of their functioning via smoking would
reduce
autonomic functioning and help explain the well-replicated finding of low resting
heart rate in antisocial individuals outlined earlier. It would also help explain the impaired autonomic functions that we have seen in offenders, such as reduced electrodermal
fear conditioning. In essence, when the fetus is exposed to smoking, the sympathetic nervous system gets shut down—and the outcome can be an under-aroused,
stimulation-seeking individual.

One would think that today mothers fully understand and recognize that smoking is bad for their unborn child. Yet the unfortunate reality is that in the United States about a quarter of all pregnant mothers smoke, while in the United Kingdom a quarter of smokers who become pregnant continue to do so during pregnancy.
⁹⁶
Smoking remains a likely contributor to the violent offending in the offspring of these mothers.

In 1992, the double killer
Robert Alton Harris was gassed to
death in
San Quentin prison, the first execution in California in twenty-five years. The terrible nature of his crime, in fact, likely contributed to the new wave of executions in the state. The murders occurred in 1978. Harris and his brother were looking to steal a getaway car for a planned bank holdup when they spotted a couple of teenagers in a green Ford eating Jack in the Box burgers. At gunpoint the boys were forced to drive to a wooded area near a lake under the promise that they would not be harmed. Once there, Harris shot and killed both boys. And it’s at this point that, for a jury listening to testimony, it becomes more psychologically gruesome.

Just as Harris was about to execute the terrified boys, one of them—sixteen-year-old
Michael Baker—pleaded for his life. According to a witness who shared a cell with Harris after his arrest, Harris boasted that he told the poor boy, “Quit crying and die like a man.” In those moments of impending doom, the petrified boy started to pray to God. Harris’s response? “God can’t help you now, boy; you’re going to die.”
⁹⁷
After the executions, and just as
callously, Harris calmly finished off the rest of the murdered boys’ half-eaten hamburgers, and flicked pieces of the homicidal gore from the barrel of his gun.
⁹⁸
The heartlessness and clear lack of conscience, combined with the fact that Harris had just been released from prison for another murder, made him a clear candidate for the gas chamber.

What is also true of Harris is that he was born with
fetal alcohol syndrome. If
smoking is problematic during pregnancy, you can imagine what the negative effects of consuming significant amounts of alcohol may be. Again, the model here is that alcohol consumed by a woman during pregnancy is a significant source of damage to the fetal
brain, and this brain impairment predisposes her offspring to violence. There are four features of fetal alcohol syndrome as first established by the pediatrician
Kenneth Jones in 1973:
⁹⁹
exposure to alcohol during pregnancy,
craniofacial abnormalities, growth retardation, and
central nervous system (CNS) dysfunction as evidenced by
learning disabilities or
low IQ. The craniofacial abnormalities in fetal alcohol syndrome sufferers can be striking. The middle part of the face is relatively flat, the upper lip is quite thin, and the eyes tend to be widely spaced. The
uncanny result of this is that two unrelated babies in a hospital can look alike if they both have
fetal alcohol syndrome. The rate of this syndrome is about 3 babies in every 1,000.
¹⁰⁰
More common, however, is the condition of “fetal alcohol effects”—in which just some of the symptoms described above are present—with a base rate of approximately 1 percent.

Matching the striking nature of fetal alcohol syndrome is the relationship it bears to crime and delinquency. Perhaps the most comprehensive study conducted to date is that of
Ann Streissguth and her colleagues at the University of Washington in Seattle.
¹⁰¹
Although fetal alcohol syndrome is relatively rare, Streissguth was able to obtain an incredible 473 cases of either fetal alcohol syndrome or fetal alcohol effects from the Pacific Northwest, and assessed outcomes for antisocial behavior at age fourteen. A full 61 percent of the sample evidenced juvenile delinquency. Sixty percent were expelled or suspended from school. Forty-five percent showed some form of
inappropriate sexual behavior, such as incest, sex with animals, or masturbation in public. More than half of the boys and 33 percent of the girls went on to be arrested or convicted for their offending.

Streissguth’s work started off with
fetal alcohol syndrome and looked at outcome for antisocial behavior. Another way one could look at it is to start off with a population of antisocial individuals and examine rates of fetal alcohol syndrome and fetal alcohol effects. This is exactly what
Diane Fast and her colleagues did, and they found rates of 1 percent for fetal alcohol syndrome—more than three times the expected base rate—and a full 22 percent for fetal alcohol effects.
¹⁰²
There is little doubt that the mother’s intake of alcohol during
pregnancy can raise the odds of problematic behavior.

As with
smoking during pregnancy one can argue that there is a third factor that underlies the fetal alcohol syndrome–antisocial relationship. Again, a genetically informative adoption study came to the fore in ruling this factor out.
Remi Cadoret at the University of Iowa studied the adopted-away offspring of mothers who drank alcohol during pregnancy and found that they too showed higher rates of conduct disorder and adult antisocial behavior compared with adopted children whose biological mothers did not drink during pregnancy. Because the children were adopted away from their biological mothers after birth, their antisocial behavior cannot be attributed to the fact that mothers
who drink may be poor caregivers during their child’s development. It does look as if the exposure to alcohol during pregnancy is causally related to crime outcome.