it could be redeemed at the end of the game for money. Punishment, therefore, held negative consequences for both the thief and the victim. The thief would be subjected to a dose of hot sauce and the victim would use up a resource that could have otherwise earned back some (but not all) of the money the thief had stolen.
But here’s the trick: the thieves didn’t exist. Experimenters manipulated the rounds in order to divide men into different test and control groups. Some men had only a small amount of their earnings “stolen” from them, while others faced significantly greater losses. The reactions of each man were recorded and compared to their level of provocation — how much was stolen from them — and their MAO-A genotype.
Not surprisingly, men with either genotype who’d had significant portions of their earnings stolen from them acted more aggressively than men who’d lost less. However, among the men who’d lost considerable amounts, those with a low-reactive MAO-A were far more likely to pursue vengeance than those with a high-reactive version of the gene. This implies that men with low-reactive MAO-A only display greater aggression when provoked by a perceived slight, and not as a result of having an inherently domineering personality.
The warrior gene theory has garnered significant criticism since its inception, particularly because low-reactive versions of the MAO-A gene are less prevalent among Caucasians than other races, lending the research an unfortunate air of racial divisiveness. It’s not within the stated purpose of this book to weigh in on that particular debate, but whether the “warrior gene” exists or not, it is, at most, only half the story. For behaviours cannot be dictated by genes alone. Genetics may determine how easy it is to push a person’s buttons, but the finger that actually pushes them belongs to the early caregiving environment — how a person was parented.
Section 2
The Broken Filter
“Genes and family may determine the foundation of a house,
but time and place determine its form.”
—Jerome Kagan
Chapter 4
Messy Metaphors
Mrs. Munroe has a good group of students this year. Grade eights can be a challenge — precariously balanced as they are between childhood and adolescence, their hormones overcharged and as volatile as nitroglycerin — but for the most part, she can’t complain. Only two of her students trouble her, and for very different reasons.
Joey is pure energy. Unfortunately, he rarely puts it to good use. He disrupts classes, swears at teachers, and bullies his classmates mercilessly. Over half a dozen students have complained to Mrs. Munroe about him. One claimed Joey stole his backpack and threw it onto the school roof. Another said Joey shoved her in the janitor’s closet and held the door shut until after the second period bell rang. Still another showed Mrs. Munroe her binder, which had been stabbed repeatedly with a pen and defaced with permanent marker. She claimed Joey did it.
Though Joey terrorizes his peers more or less without prejudice, a few students actually look up to him. He flouts rules with an abandon they find hopelessly alluring. He chain-smokes during his lunch hour, standing defiantly just a few feet off of school property, where the teachers are powerless to stop him. He regales anyone who will listen with stories of binge drinking and illicit sex. Mrs. Munroe is pretty sure the sex talk is pure bravado, but the drinking, at least, she believes to be true. Joey has shown up to school flush-faced and giddy on more than one occasion, the smell of stale beer on his breath. None of her punishments seem to have any effect on his behaviour. He careens through life like a transport truck with its brakes cut, flirting with disaster and constantly gaining speed.
Mrs. Munroe’s other problem child is Erika, though a less empathetic teacher would hardly consider her a problem at all. She never acts out, or breaks rules, or draws any attention to herself whatsoever. This is not to say she’s an ideal student — she doesn’t participate in class, and often fails to do her homework. Her test performance is spotty; sometimes she scores very well, but at other times she hands tests in with many questions left unanswered.
For the first few weeks, Mrs. Munroe suspected that Erika had some sort of learning disability, but she has become convinced this is not the case. The work Erika does complete is of exceptional quality. She writes eloquently, and can solve fairly complex math problems without struggle. The trouble is that, more often than not, she simply doesn’t bother to do the work. She doesn’t seem to have the energy. She smiles wanly when Mrs. Munroe talks to her about her assignments, shrugs off her teacher’s concerns, and completes just enough of her schoolwork to get by and stay under the radar.
The other students sometimes tease Erika, but she’s not a very satisfying target. Getting a rise out of her is pretty much impossible. A few children give half-hearted attempts now and then, but mostly they just leave her be. She has few friends, and during lunch she sits alone, pushing food around her plate. Her thin arms bear scars from frequent cuts and gashes. These wounds are not the hallmarks of domestic violence — Mrs. Munroe has never spotted bruises, black eyes, or taped-up fingers. They look self-inflicted.
On the surface, Joey and Erika seem like polar opposites. Joey’s personality is aggressive and forceful; Erika’s is shy and yielding. Joey does everything he can to draw attention to himself; Erika does everything she can to avoid it. Joey torments others; Erika torments herself. Yet these two seemingly disparate conditions share a common root. Psychologists have found that, beyond the superficial differences in behaviour, aggression and depression are often different symptoms for the same disease: poverty, neglect, emotional distance, and abuse by parents. Spending time with troubled children can often reveal the truth of this seemingly self-contradictory notion. Withdrawn, shy students and bullies alike often share deep-seated and painful insecurities rooted in their family environment. Given this connection, it may not be all that surprising that the same few genes can make a child susceptible to anxiety and aggression, apathy and hyperactivity. The body of research supporting this notion is new and fairly small, but like a well-nourished child, it is growing with astounding speed.
“Internalizing behaviours” are, in a way, the invisible cost of maltreatment. They do not call attention to themselves; if anything, they strive to hide from view. Erika, the self-mutilating student we described earlier, perfectly exemplifies internalizing behaviour. She’s shy, withdrawn, constantly fatigued, and prone to depression. Her intelligence and talent are hamstrung by her overwhelming sense of apathy, a black hole sucking away her every ounce of energy and optimism, leaving her feeling hopeless and alone. Nervousness and anxiety are also frequent symptoms of internalizing behaviour, though they can be difficult to see. If Erika experiences them, she hides them well behind a veil of lethargy and indifference.
Children exhibiting internalizing behaviours often feel the same anger as those exhibiting “externalizing behaviour” (think of the rebellious and irascible Joey), but they tend to turn it on themselves, where it manifests in body mutilation, drug use, or eating disorders. They draw their pain inward, but that doesn’t mean it can’t be felt by those around them. Depression throbs like a wound in a family’s flank, one we can spot and bandage with antidepressants, but are all too often unable to actually heal. Though hard to notice at times, internalizing behaviours can be diagnosed, and researchers are growing increasingly confident in their prediction of what causes them. Unfortunately, the answer is complex, subject to variation, and incomplete.
This is not to say it isn’t useful. As the following studies will show, even a partial understanding of what causes internalizing behaviours can make treating them significantly easier.
Nothing to Fear but Fear Itself
Mice make ideal test subjects. Though less intelligent than their distant cousins, rats (themselves popular among researchers), mice are smart enough to train, have short birth cycles, and reproduce prodigiously, allowing researchers to observe the effects of an experiment over multiple generations without waiting years for the results to come in. Female mice reach sexual maturity when only 8 weeks old, and can birth 5 to 10 litters per year, each of which contains anywhere from 3 to 14 mice. That’s a lot of births, and a lot of mice. It’s also an ideal opportunity