The Anatomy of Violence (15 page)

We need to ask why hippocampal impairment would make an individual more likely to offend. For one thing, it makes up part of the emotional
limbic system. We know in turn that psychopaths and other offenders have abnormal emotional responses. The hippocampus is also part of the neural network that forms the basis for the processing of socially relevant information, and it is involved in recognizing and appraising objects. Disruption to such a system could in part relate to the socially inappropriate behavior shown by some violent individuals, as well as the misrecognition and misappraisal of ambiguous stimuli in social situations that can result in violent encounters.
³⁶

The hippocampus is critical for learning and
memory. It’s one of the first areas to go in people with
Alzheimer’s disease. With my longtime colleagues
Rolf and Magda Loeber in Pittsburgh I studied the ability of schoolboys to remember both verbal material and nonverbal, visuospatial material. The result? Boys who had been persistently
antisocial from the age of six to sixteen as rated by their parents and teachers did more poorly on these hippocampal memory tasks than controls.
³⁷

We also know that the hippocampus plays a role in
fear conditioning, and as we’ll see in a later chapter, antisocial and psychopathic individuals have a particular deficit in this form of learning. Psychopaths are fearless individuals, as are many other violent offenders. It’s worth noting that researchers from Italy and Finland have found a structural abnormality in the hippocampus of psychopaths, which plays an important role in fear conditioning and emotional responding.
³⁸

Yet there’s more to the hippocampus than
memory and ability. It is a key component in the limbic circuit that
regulates
emotional behavior,
³⁹
and it has been implicated in
aggressive,
antisocial behavior in both animals and humans.
In animals, it regulates aggression through its connections to deep structures in the middle of the brain, including the lateral hypothalamus and what’s called the periaqueductal gray, structures important in controlling both defensive rage attack and
predatory attack.
⁴⁰
So a poorly functioning hippocampus will be of little help to either an offender who is beginning to fly off the handle in the first stage of an argument, or one who is seeking revenge.

Another
brain area that is believed to be dysfunctional in offenders is the
posterior cingulate, lying more toward the rear of the head and deep inside the middle of the brain. This region has been found to be poorly functioning in adult criminal psychopaths,
⁴¹
conduct-disordered boys,
⁴²
and aggressive patients.
⁴³
Because this brain region is also important in the recall of emotional memories
⁴⁴
and the experiencing of emotions,
⁴⁵
a disturbance to this area will likely result in a disturbance in emotion, including causing
anger. We also know that the posterior cingulate is involved in
self-referential thinking—the ability to reflect back on oneself and understand how one’s behavior can affect others.
⁴⁶
So if a psychopath fails to understand how his actions can harm others, this could help explain his thoughtless, antisocial acts and his failure to accept responsibility for his actions.

Killing is one thing. Striking your wife across the face is another. The trouble with research like mine on murder is that killing is very rare. What about more common acts of serious
violence like
spousal abuse?

Of course, I’m not saying that spousal abuse is trivial by any means, but it’s far more common than homicide. Are spouse-abusers different from killers in brain functioning? Or can we discern similar patterns in these common-variety offenders? To help answer that question, let’s take a trip to
Hong Kong.

It’s a fantastic place. I took my family there when I was on sabbatical at
Hong Kong University. People were so sweet and polite. The very first morning that I took my two young boys,
Andrew and
Philip, to Victoria Kindergarten in the Fortress Hill area, we were stopped in the street by a young woman. She asked if she could help hold the boys’ hands. Well, why not? So off we all marched, hand in hand to preschool, where she duly said good-bye to the boys, thanked me, and vanished into thin air amid the bustling streets.

Strange, isn’t it? Maybe she was a nutcase, but I don’t think so. She was a smartly dressed professional. To her, my two-year-old tots were cute curiosities, decked out in their red school blazers, gray trousers, satchels, and mixed Asian-and-Caucasian faces. It was typical of the graciousness,
courtesy, and respect for the family and
children that Hong Kongers have.

Yet lurking beneath that civilized façade lies the cruel visage of domestic violence. I did a survey of 622 Hong Kong undergraduate students. They were not all rich kids by any means, but they were largely from the privileged classes. You don’t expect much to have gone on in their homes in their formative years. But I nevertheless asked them how their parents dealt with conflicts before the kids were eleven—
before
they could turn into troublesome teenagers. Sixty-two percent had parents who would insult or swear at them, 65 percent had parents who would do or say something just to spite them, while 48 percent were slapped or spanked.

No big deal, you’ll say, if you remember being on the receiving end of a good spanking or two as a child. Surely this happens in the best of homes. But let’s get beyond the simple stuff. Fifty-one percent went on to admit that their parents would hit them with an object. Forty percent were
physically beaten. Six percent had actually been
choked
, while 5 percent had been deliberately burned or scalded. Seven percent had even been threatened with a knife or gun. In all cases it was their own parents perpetrating the abuse. So how often did
your
parents choke and burn you or put a gun to your head before you turned eleven?

Serious domestic violence was pretty rampant even in the homes of these educated, better-off undergraduates. True base rates are likely a lot higher, since people forget what really happened after ten years. Plus, you never want to admit—even to yourself—that you had parents bordering on the sadistic and inhuman. Some of these kids were having the living daylights beaten out of them—some repeatedly—behind closed doors. And these are the better-off kids. Heaven knows what was happening—and still is going on—to kids from much poorer homes in Hong Kong.

And where the kids are getting beaten, the wives are being bashed. Today it’s hard to believe, but until about 1980 spousal abuse was hidden under the carpet at home.
⁴⁷
A man who gave his wife a belting was not considered a criminal; such treatment was part and parcel of everyday married life. Even after the recent criminalization of spousal abuse, wife battering is still rife. The prevalence of spousal abuse each year is approximately 13 percent in the United States, with an estimated 2 million to 4 million victims a year.
⁴⁸
It accounts for about half of all female homicides and is a leading cause of injury to developing fetuses.
⁴⁹
It’s a
shocking, disgraceful, criminal offense, and yet it’s all too common and frequently tolerated in some households.

Let’s face up to these spouse-abusers. If we can look beyond their eyes and into their
brains, do these men also have a dysfunctional cortex? They batter women, but is that because they have battered brains?

Tatia Lee is a brilliantly creative clinical neuroscientist at
Hong Kong University with a penchant for sailing into uncharted waters. She conducted some of the very first brain-imaging work on
lie detection, and she was just a couple of doors down from my office during my time there in 2005. Together with her graduate student, we teamed up to test our ideas on
spousal abuse. We recruited twenty-three men referred by police to social-welfare departments and psychology practices for physically abusing their wives. Our main hypothesis was that such men may
overrespond to emotional stimuli, and that that may in part be a cause of their abuse. We measured their
reactive and
proactive aggression and also gave them two verbal and visual emotion tasks.

The verbal task is called the
emotional
Stroop task. The subject is first presented with the name of a color, like “blue.” They then see an emotionally negative word like “kill,” which is either printed in blue or another color, and have to judge whether the color of the word “kill” was blue or not. The same thing is done with nonemotional words, like “change.” We then measure how long it takes them to respond. People who take longer to respond to the emotional word than to the neutral word are showing a cognitive bias to negative affect stimuli—meaning that the negative emotional nature of the word has hijacked their brain’s attention and slowed down their responses.

In the visual task, the subjects viewed neutral pictures like a chair and also emotionally provocative pictures—things like a man holding up another man in a
robbery with a gun to his head, or a man holding a woman from behind with a sharp knife across her throat. In both of these verbal and visual tasks we scanned their brain using
functional magnetic resonance imaging (fMRI). Our research resulted in fourfold findings.

First, spouse-abusers were strongly characterized by
reactive aggression—where the individual responds aggressively in the face of provocation. In contrast, once we controlled for this, the spouse-abusers showed no proactive aggression. They were not using aggression in a planned, premeditated, manipulative fashion.

Second, in the emotional Stroop task, the spouse-abusers were
slower in responding to emotional words. Negative emotional stimuli were capturing their attention much more than normal.

Third, in functional brain scans during the emotional Stroop task, our
spouse-abusers showed much greater activation of the emotional
amygdala to negative-emotion words, together with less activation in the regulatory prefrontal cortex.

Fourth, when batterers saw pictures of visually
threatening stimuli, they showed hyper-responding in widespread brain areas covering the
occipital-
temporal-
parietal regions. These regions are exceptionally sensitive to the recognition of objects
⁵⁰
and to spatial perception.
⁵¹
They indicate that batterers experience greater visual arousal when exposed to threatening stimuli.

Putting these four findings together, a pernicious pattern unfolds. Spouse-abusers have a reactive aggressive personality that makes them more likely to lash out when provoked. Emotional words inordinately grab their attention. They are less able to inhibit the distracting emotional characteristics of stimuli, resulting in impaired cognitive performance. When presented with aggressive stimuli their brains overrespond at an emotional level and underrespond at a cognitive control level. Spouse-abusers are constitutionally different from other men.

These neurocognitive characteristics of batterers may partly contribute to their abusive behavior. Some researchers have documented that batterers do not listen to reason, and instead emotionally react out of all proportion to a situation.
⁵²
Excessive attentional processing to a visual stimulus like a frown or a scolding voice may distract the batterer’s attention and make him misinterpret the social interchange. It could contribute to the racing thoughts, irrational behavior, and escalating negative emotion that characterize wife-batterers.
⁵³

To my knowledge, these are the first physiological studies of
any
kind to show brain abnormalities in spouse-abusers when reacting to emotional stimuli, and the first to demonstrate hyperreactivity to threatening stimuli. Our findings challenge an exclusively social perspective on spousal abuse and suggest instead a neurobiological predisposition to battering. Historically, the prevailing clinical perspective has been that spousal abuse is a conscious, deliberate, and premeditated use of power to subjugate and control the female partner for selfish instrumental gain.
⁵⁴
An alternative hypothesis that Tatia and I suggest is that spousal abuse has a significant brain-based reactively aggressive component.
⁵⁵

Is this a newfangled excuse for wife-abuse? I’m not exactly saying that abusers are not to
blame. And I’m not saying that all abusers are like this. But I do think we need to recognize that there’s more to domestic violence than the traditional feminist perspective cares to admit. Feminists argue that the cause of spousal abuse lies in a patriarchal society that sanctions men’s using physical power to control women. We argue instead that neurobiology nudges some men to overreact at home and that we need to consider a contribution by the brain to spousal abuse. Why? Because traditional treatment programs to treat spouse-abusers based on the feminist perspective simply do not work.
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We need to incorporate neurobiological perspectives into domestic-abuse treatment programs if we genuinely want to eradicate this completely unacceptable behavior of men toward women.

So far we have been talking about people who are characterized by the media as brutes, monsters, and villains. We have been discussing despicable deeds that include murder,
child
rape, and wife-battering. And you may be sitting there dispassionately reflecting on how this other half lives, and what exactly makes these mean men tick.

But what about you? What’s ticking away inside you when you perpetrate an antisocial act? Oh, so you’re not antisocial? You really think that? Well, not perhaps antisocial at the level that we have been discussing so far, but let’s turn to two arenas that will be much more familiar to your daily experience than murder and spouse-battering. You’re not perhaps so wonderful after all.