The Anatomy of Violence (40 page)

So cadmium can be a killer, not just in people like Huberty, and not just in the United States. Certainly, hair samples from violent offenders in the U.S. show them to have more cadmium than nonviolent offenders.
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High hair-cadmium levels also characterize U.S. elementary schoolchildren with behavioral problems.
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The same is true for schoolchildren in
China, a leading producer of cadmium. The
Dabaoshan mine in the city of Shaoguan in the Guangdong province is a multi-metal mine. Water is used to leach the ore, and the waste water is then transported by rivers to local villages, delivering a large dose of
heavy metal to the villagers. The result is that the crop region in this countryside has
sixteen times
the recommended level of cadmium. A study of schoolchildren living downstream from the mine showed that hair-cadmium levels explain 13 percent of the variation in their aggressive and
delinquent behavior.
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Cadmium is quite a heavy-metal key on the biological key chain unlocking the etiology of violence.

It’s not hard to see how people living near a mine are exposed to
cadmium, but what about the rest of us? Not surprisingly, cadmium is a hazardous substance that can cause death and is banned by the European Union for use in electrical equipment. Yet about 75 percent of all cadmium in the United States is used in rechargeable
nickel-cadmium batteries rolling around your home right now. Not too harmful there, perhaps, but cadmium does find its way into the environment from municipal waste grounds and fossil fuels because products containing cadmium are rarely recycled.

The people most susceptible to cadmium? Smokers. They inhale about 10 percent of the cadmium content of a cigarette, which gets nicely absorbed into the bloodstream from the lungs.
⁸⁹
They end up with five times the cadmium levels of nonsmokers.
⁹⁰
The rest of us get exposed too, because foods like offal (the internal organs of animals) and
cereals
⁹¹
account for 98 percent of our cadmium intake. In contrast, seafood, which we saw earlier to be associated with
lower
violence, accounts for only 1 percent.
⁹²

The twist here is that the amount of cadmium acting on your body is a function of other factors.
Iron blocks the intestinal absorption of cadmium.
⁹³
Women on
vegetarian diets have reduced iron levels and they also have increased cadmium exposure. If they smoke as well they will have an exponential increase in cadmium. This may partly explain why low iron is associated with violence—individuals with low iron levels are more susceptible to the negative effects of cadmium on the brain.

Everett “Red” Hodges is one of those larger-than-life characters whose charismatic and witty stories blend with forceful argumentation to make you believe almost everything he has to say. His sons have been both perpetrators and victims of crime. One was a rebel without a cause who got into a load of trouble as a juvenile delinquent. The other was mugged in a parking lot and very badly beaten up, suffering brain damage as a result. “My son was damn-near murdered,” Red said in an interview. “I know the anguish and suffering that families go through. And you can’t put a price on it.”
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Red reasoned that if the criminal justice system had done a better job of dealing with the neurobiology of violence, his son and many others would never have been the victim of violence. The anguish of many family members would have been spared.

Red pins the blame on one particular
metal—manganese. Having made a good deal of money in a Bakersfield oil field in California, Red Hodges sank a million dollars into funding efforts to investigate his hypothesis. Working with Red,
Louis Gottschalk at the University of California,
Irvine, demonstrated that three different samples of violent criminals had
higher levels of manganese in their hair than controls did.
⁹⁵
Roger Masters at Dartmouth University similarly showed that areas in the United States with higher levels of manganese in the air have higher violent-crime rates—even after controlling for multiple socioeconomic confounds.
⁹⁶

At the same time, the manganese debate is a political hot potato, and it’s hard to know who’s right and who’s wrong. Critics reasonably argue that the evidence is mixed and that we cannot easily untangle cause-and-effect relationships from correlational studies.
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What helps here are longitudinal studies involving teeth. The cusp tip of the first molar gives a handle on manganese exposure halfway through pregnancy—a time when a fetus’s brain is rapidly expanding. Using these teeth, researchers showed that kids with high prenatal manganese levels had disinhibited, antisocial behavior across the board on a host of antisocial-behavior measures.
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What causes excessive
manganese exposure during pregnancy? A deficiency in
iron—the micronutrient that when low is associated with high antisocial behavior—enhances manganese absorption. Women with low iron levels absorb about four times more manganese than women with high iron levels.
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An early postnatal source of manganese is
soy infant formula, which has eighty times the amount of manganese that natural
breast milk has. It’s possible that the higher IQs found in breast-fed babies may be due to formula-fed babies’ being exposed to high manganese, because manganese excretion is controlled by the liver. The livers of babies are underdeveloped, and consequently they are less able to excrete manganese. The excessive manganese could then result in poorer brain functioning and lower IQs.

Put the two together and you begin to build a recipe for violence. Pregnant mothers have a tendency to have low iron. This will result in increased manganese exposure to the fetuses. Then, when the nippers are born, they get soy milk with a hefty dose of manganese that their little livers cannot deal with. The potential result? One more strike on the brain. Higher
manganese levels in children can result in impairments in cognitive speed, short-term memory, and manual dexterity.
¹⁰⁰
As we
noted earlier, this
neurocognitive dysfunction predisposes individuals to violence. Furthermore,
manganese reduces
serotonin, a neurotransmitter that when low causes a predisposition to impulsive violence.

Given this, perhaps it’s not too surprising that
fifteen studies
on workers exposed to manganese in all corners of the world—including Chile, Great Britain, Egypt, Poland, Brazil, the
United States, Scotland, and
Canada—without exception report significant mood disruption, including aggression, hostility, irritability, and emotional disturbances.
¹⁰¹
In Chile the term used is
locura manganica
—meaning “manganese madness.” It refers to violence, mood disturbances, and irrational behavior. It’s just the type of craziness that James
Huberty reported as the reason for leaving his welding job, this time for another mad metal—
cadmium.

It has been documented that the aggressive acts of workers exposed to manganese result in
“stupid” crimes that are not premeditated and motivated by gain, but more a result of brain impairment resulting in poor emotion regulation and impulsivity.
¹⁰²
Not surprisingly, low intelligence is an extremely well-replicated risk factor for violent offending, a risk factor that could in part be caused by an excess in manganese.

Moving from manganese to mercury you might expect the same pattern of results to emerge. But they don’t. Mercury is mysterious. Of all the
heavy metals, this one may or may not play a role in violence—a fact that is both striking and enlightening. Mercury is toxic to the brain and other body organs, with about half of human-generated mercury coming from
coal plants. Dental amalgams are another source, and fish are also argued to be a major dietary contributor.

Despite its toxicity, to my knowledge there are no convincing demonstrations that antisocial and violent individuals have higher mercury levels. It is also surprising that there are so few studies on mercury levels and cognitive ability in community populations. Two major prospective studies that have been done on blood-mercury levels and cognitive-behavioral functioning show conflicting findings.
¹⁰³
One study, conducted in the
Faroe Islands, between Scotland and Iceland, found high mercury to be associated with poorer cognitive functioning.
¹⁰⁴
The other study, in the
Seychelles, which is just up the road from
Mauritius, in the Indian Ocean, found no association between
mercury and cognitive-behavioral outcomes.
¹⁰⁵
Reviewers are at a loss to explain the discrepancy, putting the difference down to “culture.”
¹⁰⁶

Yet if we put together a few seemingly unrelated facts, these geographically contradictory findings can make sense. Where do people get
mercury from? Supposedly from eating fish that are high up in the food chain—particularly shark, swordfish, and king mackerel, which are certainly on the no-go list for pregnant mothers. In the Faroe Islands they also eat a whole load of
pilot whale, especially outside the capital city. What’s the deal with pilot-whale meat? It’s not just very high up in the food chain and high in mercury, but it’s also low on selenium.

Selenium? This is a mineral that defends the brain against “
oxidative stress,” a process in which the brain cell takes up too much oxygen, resulting in the production of free radicals that damage
DNA and the cell membrane, resulting in cell death. Selenium not only protects against this damage but, more important, it binds with mercury. Like a magnet, selenium latches onto mercury and keeps it from binding with brain tissue, thus preventing brain and cognitive impairment.

If you think about it, fish seem to do okay with all that mercury leaching out of the seabed, and many species are packed with selenium. Going back to the two studies with contrasting results, the high-mercury and low-selenium diet in the Faroe Islands translates into poor cognitive and behavioral functioning. And yet in the Seychelles, pregnant women are also exposed to mercury, eating twelve portions of fish a week. That’s a lot, twelve times the
consumption of American women. So what is different in the Seychelles and the Faroe Islands? In the Seychelles they do not eat pilot whale, which is low in selenium. Instead they eat fish high in selenium that buffers them from mercury and its cognitive impairments. Their diet thus protects them against any damaging effects of mercury, as well as providing a high dose of the beneficial
omega-3. We shall return to omega-3 in a later chapter when we pose prevention strategies to fight violence.

So we are seeing that biology plays out in the environment and in the physical-health arena when it comes to the makings of malevolence. Some heavy metals take their toll on the brain and predispose people to violence. But health is a multifaceted construct, and it acts in ways other than diet and environmental toxins to shape violence. Let’s not forget
mental
health. Biological impairments can also make men mad, and madness can make men mean. Women too, perhaps even more
than men.
Mental illness has its roots in genes and neurotransmitter abnormalities that mess with our minds. And it’s when our minds are mucked up that we are most prone to violence. One prominent and major mental illness that can do this is
schizophrenia.

I’ve long had an interest in schizophrenia because it was, in a way, pivotal in moving me out of accountancy and into criminology. Not that I became psychotic adding up all those numbers at British Airways—although at times I did think I was losing my mind somewhere within those cabin-crew accounts. But this clinical disorder did radically change my life. Haven’t we all had those pivotal moments in life when a seemingly chance, inconsequential event changed everything? You pick up some random book, just like you picked up this one, and something clicks. The next thing you know, your life takes a sudden turn—all because of one capricious, unpredictable, and seemingly innocuous experience.

In my case it was a Saturday morning just before lunch in the early summer of 1973, and I was bored to tears working at Heathrow. I knew I’d made a really bad life decision in becoming an accountant, and I was absolutely miserable—had been for months. How had I messed up so badly? I was hungrily hunting for some books at a bookstore in Hounslow where I lived to read over my Saturday lunch treat—an “American” cinnamon apple pie and ice cream—and it leaped out at me. A slim paperback by
R. D. Laing and
Aaron Esterson entitled
Sanity, Madness, and the Family.
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Laing’s riveting collection of eleven case studies of schizophrenic patients challenged the prevailing medical model that schizophrenia was a brain-based disorder. Instead this existential psychiatrist argued that schizophrenia had an environmental
basis stemming from faulty communication within the family. Schizophrenics have outrageous and bizarre beliefs, but their madness becomes understandable when we consider the context of the family.

I had an epiphany. It was all making sense. So
that’s
how I ended up as such an oddball—it was all my nutty parents! It was a revelation that made me determined to understand myself more and to study psychiatry (I ended up studying psychology instead), to challenge the biological model of mental disorder (I eventually did the opposite), and to work in hospitals helping schizophrenic patients (trade that for four years in prison helping psychopaths). Books change our mind-set and sometimes our life—though not always in the way we anticipate, and not necessarily in the right way.

Laing and Esterson weren’t exactly right either.
Schizophrenia turns out not to be caused by faulty parent-child communication patterns but is instead a debilitating, brain-based,
neurodevelopmental
disorder characterized by
delusions,
hallucinations, thought disorder, lack of emotion, and disorganized behavior. Affecting about 1 percent of the population around the world, it frequently hits women in their early twenties and men in late adolescence, with about 40 percent of male schizophrenia cases occurring before the age of nineteen—an intriguing fact given that these late adolescent years are also the
peak age for violence in men.
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