10

Sex . . . and Love

Love does not begin and end the way we seem to think it does. Love is a battle, love is a war; love is a growing up.

James Baldwin, Nobody Knows My Name

Males and females are different. This delightful fact of life makes the world go ’round. Sex differences are at the core of biology, the driving force of evolution, and in many cases fundamental to finding the best path to good health. On close inspection, nearly every part of the human body differs slightly by sex. Even the parts that would seem to have the identical function in men and women, such as hands and feet, are immediately recognizable as either a man’s or a woman’s. Even our bare bones can tell an anthropologist if they once supported the body of a man or a woman. It should come as no surprise that the same is true of our brain, the organ that controls all bodily functions and all behavior. So, men’s and women’s innate responses to danger and the ways they snap—however slightly—are different.

This chapter explores these differences, and in particular the underlying specializations in the brains of men and women that drive sex and its intimate relationship with violence. The subject raises many intriguing questions: How are sex and violence linked? What are the differences in propensity for rage between males and females, and how do the triggers for rage and the rage reaction itself differ between the sexes? Is female rage different from male rage? How does cross-gender aggression differ from aggressive rage within the same gender? Women warriors: what makes some women attracted to danger—for example, undertaking professions in the military or police? How do men and women differ in terms of conscious and unconscious brain function in fear and threat detection? Understanding how the rage circuit operates in different genders can save relationships and lives—even a great many lives.

—

It was an ambush. Fifty enemy fighters had launched a complex attack on the small US military convoy with a hail of heavy machine-gun fire and a cacophony of explosions from RPGs spraying shrapnel, flame, and black smoke with each concussion. The convoy was trapped in a kill zone formed by a barricade of strategically parked cars. The US soldiers were caught out in the open, taking heavy fire from the enemy dug in and protected by irrigation ditches bordering the road.

Twenty-two-year-old Sergeant Hester in the Military Police squad for the Kentucky National Guard snapped into action. Leading a small team of soldiers Sergeant Hester charged through the kill zone, maneuvered into a flanking position, and assaulted the trench line, chucking hand grenades and firing M203 grenades to cut off the enemy’s escape route. (M203s are explosive grenades launched from a tube beneath the barrel of the M4 assault rifle designed for combat in close quarters.) Hester, teaming up spontaneously with Sgt. Timothy Nein, cleared two trenches. Charging into the direction of fire, Hester shot and killed three attackers. When the firefight ended and the dust began to settle, three US soldiers from the ambushed convoy lay injured, but there were no fatalities. Twenty-seven Iraqi soldiers were dead. Six were wounded, one was captured, and the remaining enemy combatants fled. Sgt. Leigh Ann Hester was awarded the Silver Star for valor—the first woman to receive the honor since WWII, and the first woman ever to receive the award for heroism in direct combat.

“Your training kicks in and the soldier kicks in,” Hester says. “It’s your life or theirs. . . . You’ve got a job to do—protecting yourself and your fellow comrades.” These are the same powerful motives that drive any soldier in combat (the Life-or-limb and Tribe triggers).

To state the obvious, men and women do not compete together in Olympic weightlifting. But at the same time, there is not a separate IQ scale for the two sexes. Neither are bravery, patriotism, or determination qualities unique to only one sex. Many women have been awarded the Silver Star for valor before Sergeant Hester received that honor. They earned it for their heroic action as nurses in combat zones, serving their country bravely before women were permitted in the armed forces.

The defensive neurocircuits of rage and aggression are built into the brains of both men and women, but the circuits have been honed by evolution to best suit the biological differences between the sexes, and also to accommodate gender differences imposed by society on men and women.

In 2007 an eleven-year-old girl typed her heart out on her blog. Not so unlike others her age, except that her heart was aching for something far beyond the typical preteen dreams of other girls. She yearned for a better world. She saw injustice and could not accept it. As a child and a female, her only weapons in this battle were her courage and commitment. In the Taliban-controlled Swat Valley of Pakistan, strict sharia law denied girls education, stifled their liberties by secluding women in their homes, and imposed forced marriages on them at an early age. Malala Yousafzai’s outspoken views began to attract widespread attention in the media, and this threatened the Taliban’s beliefs, authority, and mission. In defiance, she openly traveled to and from the Khushal Girls School, which her father founded.

“For my brothers it was easy to think about the future. They can be anything they want. But for me it was hard, and for that reason I wanted to become educated and empower myself with knowledge,” she said.

“I had a terrible dream yesterday with military helicopters and the Taliban. I have had such dreams since the launch of the military operation in Swat,” she wrote in her diary on January 3, 2009.

Nine months later, on October 9, 2012, while she was riding home on the school bus from classes, two armed men stopped the bus filled with children. “Who is Malala?” one of the men asked.

“I heard the firing, then I saw lots of blood on Malala’s head,” one of the other students recalled. “When I saw that blood on Malala, I fell unconscious.”

Malala and two of her classmates were shot. The bullet entered Malala’s forehead above her left eyebrow, pierced through her cranium, penetrated through her neck, and lodged in her back. Parts of her brain controlling speech and movement of her right arm and leg had been damaged. Her facial nerve had been severed, paralyzing the left side of her face. She was in grave danger of death.

After receiving the best possible care in Birmingham, England, where her family emigrated to escape the Taliban’s death threats, Malala, now with a titanium plate replacing her shattered skull, endured a slow and painful recovery. The young girl learned to cope with disfigurement and disability, but her commitment to her struggle against injustice did not waver. Two years and a day later, Malala Yousafzai, at the age of seventeen, became the youngest recipient of the Nobel Peace Prize in history. When the award was announced, Malala was in school. While the world media awaited her reaction, Malala insisted on finishing her chemistry class. Then she went on to history and English class, and only after school was over did she respond to reporters. Speaking graciously of the honor of sharing the Nobel Prize for Peace with Kailash Satyarthi, age sixty, an Indian citizen who worked to free thousands of child laborers, Malala was taken by the symbolism of the award uniting in peace two countries that have been fierce enemies for decades. “It gives a message to people of love between Pakistan and India and between different religions,” she said. “One [Nobel recipient] is from Pakistan, one is from India. One believes in Hinduism, one strongly believes in Islam.”

Here we see the life-risking rage of commitment against injustice is a core trait of human beings. Regardless of sex or age, this is the way our brains are wired. For Malala it was the Organization and Tribe triggers that propelled her actions. Tragically, it is not possible to simply dismiss the acts of the two gunmen who would shoot innocent children on a school bus as an aberration of mental illness. These horrible acts of violent rage were driven by the same two defensive triggers of rage in the Taliban’s minds: the Organization and Tribe triggers. This is the double-edged sword of Homo sapiens neurobiology that can slice both ways, for good or for evil. Even in England, Malala and her family remain at risk. “Some people are silent,” a businessman in the community told reporters about the neighborhood’s reaction to the Nobel Prize. “They don’t like her and her father, but others are quiet due to the possible threat from the militants.”

—

It is foolhardy for a 135-pound man to get into a physical confrontation unnecessarily with a 250-pound adversary, even more senseless for a 135-pound woman to do so, given the much greater physical strength that biology has bestowed upon adult males. For this reason, the innate responses of men and women to threats differ, as do the brain circuits that are specialized to best serve men or women in danger. The marked differences in physical strength and in reproduction between men and women have guided evolution of the human brain for the greatest success and survival of each sex over eons, but threat detection, response to danger, and aggression are necessary for any individual regardless of sex.

There are two important consequences of this biological sexual dimorphism: The sex-based differences in the brains of men and women give each sex a different type of advantage in dealing with dangerous threats. Secondly, as environments change, so do the forces that guide biology and behavior, and the modern world is utterly transformed from what it was only a few generations ago. Breaking out of a cycle that encompasses every other form of life on the planet, human beings have developed the ability to control their reproduction through technology. This very recent development has enabled women to control their destiny in a way that was previously impossible. At the same time, other technological developments have made the differences in physical strength between men and women irrelevant in many situations in the world we live in today. It does not matter at all whether the person piloting the F-16 fighter jet scrambled on September 11, 2001, to save the United States Capitol had two X chromosomes or one X and one Y, just as gender made no difference to the Taliban fighter on the receiving end of Sergeant Hester’s M203 round. Biology tells us that the present is the product of the past, but not a repetition of it. The future will develop from its footing in the present, but it will not sustain it. In Israel, a country where men and women have very separate roles assigned by traditional religious teachings, women serve in large numbers in the armed forces. Women comprise one-third of the active-duty Israeli Army, compared with about 14 percent in the United States. About 3.3 percent of all direct-combat roles in the Israeli Army are filled by women fighting together in squads with men. Sapir Yehudain, a twenty-five-year-old woman who served in combat in the Israel Army, says, “They [her male comrades] understood that we could do everything they could too.”

Still, women in everyday life are at risk of threats and aggression from men.

When the Police Are Called

WISH LIST

Donations Requested from the House of Ruth, a Women’s Shelter

Baby wipes

Pampers sizes 3, 4, 5, and 6, Pull-ups sizes 4T, 5T and 6T

Crib sheets

Infant and Toddler Sleepwear

Baby lotion, baby cornstarch powder, diapering cream Baby formula, baby food (stages 2 and 3), baby cereal baby snacks

Individually wrapped snacks and juice boxes for children coming to therapy after school

Baby bottles 8 to 9 oz., pacifiers, aspirators, thermometers, baby Tylenol and Motrin

New High chairs

Strollers

New convertible car seats only (no used).

School Supplies . . . Toys . . . Arts and craft supplies . . .

The list goes on, documenting, as if artifacts strewn about after a disaster, the shattered lives of babies, women, and children fleeing their homes to seek safe refuge in shelters like the House of Ruth to escape violent men who attack their spouses, girlfriends, and children. The clinical euphemism for this horrible rage is “domestic violence” or “domestic abuse.” A study in England and Wales found that 30 percent of the female population has experienced domestic violence.

Objectively disturbing insight into domestic abuse was played out before a nation who saw a security-camera video catch the brutal reflexive violence of the star NFL running back for the Baltimore Ravens, Ray Rice, slugging his girlfriend in the face inside an elevator and then dismissively dragging her unconscious body out into the hallway after a verbal altercation. The athlete’s powerful left hook to his girlfriend’s jaw was so instantaneous, even in slow motion it is difficult to catch it. This brutal and inexcusable violent act was not a conscious behavior. Rice snapped. As so often happens, both the perpetrator and victim are soon shocked by the behavior and seek reconciliation. “I love my husband. I support him. . . . I want people to respect our privacy in this family matter,” Janay Rice said when the incident became public after the two were married.

This security video shows why current approaches that seek to control snapping in domestic violence are often fruitless. The men who do these things often regret it immediately. Well-intentioned techniques offered to suppress the anger in domestic violence are not enough. What men (and sometimes women) must recognize is why they are suddenly experiencing a fuming rage of anger welling up inside them toward the person they love. If the individual can recognize that the rapidly unfolding incident is pushing on one of the deadly LIFEMORTS triggers, then two things should happen immediately: First, the cerebral cortex will register a potentially violent or life-threatening trigger, and second it will evaluate whether or not the situation is indeed a life-or-death threat that these deadly subconscious circuits of defensive rage are designed to counter with violence. If violence is not called for—for example, you are in an elevator in a screaming argument with your girlfriend—then the rage will quickly subside, because you will understand that it has to. Snapping violently doesn’t help you in your relationships, doesn’t work on a broader social level, and doesn’t do you any good biologically. You will remain angry, but less so, because you will know why you are angry at a biological level. This will strongly activate the prefrontal cortex to inhibit the automated snap of violence programmed into the hypothalamus. At that point the opportunity to engage the conscious mind in deliberation, employ psychology, and utilize techniques of anger management can be brought to bear.

Beyond Domestic Disputes

Some 100,000 jubilant people flooded Tahrir Square in Cairo, Egypt, in a spontaneous celebration of freedom—Egypt’s dictator Hosni Mubarak had just fallen from power. CBS news reporter Lara Logan waded into the crowd with her news team to capture the historic transition. “It was unbelievable. It was like unleashing a Champagne cork on Egypt,” Logan describes in her 60 Minutes interview. “I’ve got to be there, because this is a moment in history that you don’t want to miss.”

Her video captures the roar of the crowd screaming in excitement, chanting revolutionary slogans, bullhorns barking, hands clapping, and automobile horns honking while flashes of smoke and fireworks, camera strobes, and improvised butane-tank flamethrowers lit the mob in celebration. As the world would soon learn, Logan, a seasoned war correspondent with blond hair and green eyes, the mother of two young children, was viciously attacked and sexually assaulted by a mob of men as she attempted to report the breaking news. The attack began the instant her TV camera battery died, plunging the reporter and her team into darkness. From the instant it began it was a sexual assault.

“I’m screaming,” she said, “thinking if I scream, if they know, they are going to stop. You know, or someone’s going to stop them or they will stop themselves, because this is wrong. And it was the opposite. The more I screamed, it turned them into a frenzy.”

Stripped naked, brutalized, and sexually assaulted by hordes of men for half an hour, she would likely have died if she had not eventually been protected by a small group of Egyptian women and finally rescued by the Egyptian Army. She required four days of hospitalization to recover from her physical injuries.

Was this a case of politically motivated aggression and violence? Was Logan targeted because she was a reporter from the United States, or was she sexually assaulted because she was an attractive woman? Were her attackers a gang of criminal thugs infiltrating the crowd or members of Mubarak’s criminal security force? Alternatively, was this a riot of ordinary Egyptian men caught up in a mob frenzy of excitement and adrenaline, resulting in gang rape? Did mob mentality reduce these men to animals, like the boys in William Golding’s Lord of the Flies? The fundamental question about this rage attack is whether the violence was sexually motivated or instead, if sexual violence was used as a way to brutalize a victim for political or ideological reasons.

Because of her celebrity, Logan’s sexual assault and battery attracted world attention, but she was not the only one.

“The atmosphere was one of jubilation, excitement, and happiness as I walked, accompanied by two male companions for safety along Kasr El Nil bridge. . . . Women, children and fathers smiled, waved, and cheered happily at the camera, calling out the widely used phrase ‘Welcome to Egypt! Welcome!’” wrote twenty-one-year-old British journalist Natasha Smith, who was in Tahrir Square to film a documentary.

“In a split second, everything changed. Men had been groping me for a while, but suddenly, something shifted. I found myself being dragged from my male friend, groped all over, with increasing force and aggression. I screamed.” Her attack matched Logan’s gang assault. “Men began to rip off my clothes. I was stripped naked. Their insatiable appetite to hurt me heightened. These men, hundreds of them, had turned from humans to animals.”

In an article Smith published a year after her assault, she states that there were forty-six cases of sexual assault on the evening of Sunday, June 30, 2013, in Tahrir Square during mass celebrations on the anniversary of the revolution. She cites statistics by Amnesty International researcher Diana Eltahawy, but Amnesty International believes the actual number is much higher. According to Human Rights Watch, at least ninety-one women were raped in Tahrir Square over four days beginning on June 30, 2013: “Yasmine El Baramawy, a 30-year-old musician, told Human Rights Watch that she was raped and assaulted on the evening of November 23, 2012, for 90 minutes after going to a demonstration in Tahrir Square. After men knocked her to the ground, they ripped her clothes and cut her blouse and bra. As the attack continued, the group around her increased from about 15 to more than 100 men.”

As El Baramawy reported, “I looked up and saw 30 individuals on a fence. All of them had smiling faces, and they were recording me with their cellphones. They saw a naked woman, covered in sewage, who was being assaulted and beaten, and I don’t know what was funny about that. This is a question that I’m still thinking about. I can’t stop my mind from thinking about it.”

Were all of these men psychopaths? The facts suggest an uncomfortable conclusion that these attacks on women were sexually motivated by men in an environment where such animal brutality is tolerated. In Egypt, 99.3 percent of women have experienced some form of sexual violence. Sexual violence is used against women by police in Egypt and other places as a most brutal means of attack, and sexual assault is also used by men in the general population for cruel violence against women. Egypt is not exceptional in this respect, as the tragic story of a young woman gang-raped and tortured by six men, including one juvenile, for an hour on a bus in Delhi, India, on December 16, 2012, illustrates. “Burn them alive,” the twenty-three-year-old paramedic trainee scribbled in a handwritten statement about her attackers while semi-comatose and fighting for her life in the hospital before she died of her severe injuries. The attack sparked international outrage and exposed Indian society as a place where sexual violence against women, often by gangs of men, occurs frequently but is not forcefully prosecuted.

So-called honor killings of women who are perceived to have brought dishonor on the family in countries like India and Pakistan still take place today; some are even committed in the United States by immigrants from countries where honor killings frequently occur. In 2014, Farzana Iqbal, a twenty-five-year-old pregnant woman, was beaten to death publicly by her father and her other family members in front of a court in India because she had married the man she loved rather than the man who had been prearranged for her by her parents. Iqbal’s husband, Mohammed Iqbal, said police did nothing during the fifteen minutes of violence and murder that took place right outside the Lahore High Court.

As my daughter and I were being chased through the streets, back alleys, shops, and restaurants in Barcelona trying to elude that gang of pickpockets determined to extract revenge, I felt a powerful sensation that I had never felt before—I felt like prey. In the midst of the chase with my daughter at my side, a sudden revelation overcame me: This is a feeling that all women must have—the sense of being prey. Even as we ran to escape the gang members this sorry realization stirred a sense of pity in my gut for the plight of my two daughters and, I suspect, all women. The possibility of being sexually assaulted never crosses the mind of a man, but that reality is never far from a woman’s mind. Quickly it became obvious to me that my daughter was very good at the role of eluding predators. Kelly would consistently spot the bad guy before I did and would draw him to my attention. During the two-hour chase I came to rely on what was clearly her superior skill at spotting the predator as my mind raced to devise tactics to evade them, and to engage them physically if that became necessary to defend ourselves. It was a powerful partnership.

Studies show that both men and women recognize an angry male face faster than an angry female face. Presumably this is because males are larger and more aggressive, and therefore men present a greater physical threat. Much the way our brain circuits are tuned to spot snakes instantly, so too has our brain’s perceptual system been fine-tuned to spot the face of an angry man as quickly as possible. The emotions of anger and fear are portrayed differently in facial expression, conveying instantly and unambiguously the mental state of any other person regardless of race or language. Interestingly, both men and women detect angry faces faster than fearful faces. This subtle refinement in the brain’s perceptual systems to quickly distinguish these two similar expressions makes sense. Both expressions signal impending danger, but an angry face originates from the source of an immediate threat, whereas a fearful face warns of danger in the vicinity. A quicker response to anger gives an individual an advantage in responding appropriately.

Other studies show that women are faster than men in recognizing nonthreatening facial expressions such as happiness or sadness. This makes women more attuned to socially relevant expressions. Men, however, are quicker at recognizing angry male faces than women are, which is consistent with their direct engagement in activities requiring physical aggression and defense that have been their domain throughout the course of human evolution. Our pursuers in Barcelona were not expressing outright anger on their faces; they were hunting us down, and somehow, Kelly always seemed to spot them closing in on us before I did.

Violence against women is a deplorable criminal act. It is universally condemned by all decent men and women and it is an inconceivable behavior for most men, but sexual violence is a human behavior that is committed in a state of rage, so we are forced here to confront it analytically. All behaviors are the product of the brain. Looking at this species, Homo sapiens, in an objective fashion the way a zoologist would observe any animal behavior, we can see this violent human behavior does occur in certain circumstances and in certain environments. There is no question that sex and violence are linked. Sex (the Mate trigger) is one of the most powerful triggers of rage.

Reflecting on his vast experience with crime, Clarence Darrow, the famed defense attorney noted for defending high school teacher John Scopes for violating Tennessee law against teaching evolution in public schools, wrote, “It seems to me to be clear that there is really no such thing as crime, as the word is generally understood. Every activity of man should come under the head of ‘behavior.’” Crimes are human behaviors that are prohibited by law and enforced by sanctioned violence by societies to maintain social order or to preserve power by rulers over populations. Without this social regulation of human behavior, human societies degenerate into violent chaos.

Recent statistics show that 30 percent of all Internet traffic is pornography. Porn sites have more visitors each month than the Internet giants Netflix, Amazon, and Twitter combined. Porn industry revenue in the United States is twice the combined revenues of ABC, CBS, and NBC—$12 billion annually, despite the growing trend for free pornography. Some 40 million adults in the United States regularly visit Internet pornography websites. As many as 10 percent of viewers report uncontrollable addiction to Internet porn.

Sex is a normal biological function, so the appeal of pornography on a neuroscience level is not surprising, but 88.2 percent of pornography contains physical aggression, and 48.7 percent of pornography contains scenes with verbal aggression. The targets of physical and verbal aggression in pornography are overwhelmingly female, 94 percent.

From the viewpoint of brain function, addiction to pornography is no different from addiction to alcohol, drugs, or gambling. All of these addictive behaviors activate the release of the neurotransmitter dopamine from the brain’s reward system (in the dorsal striatum). Both sexual activity and physical aggression stimulate the same reward center to release dopamine and stimulate the brain’s pleasure circuits.

Playing video games also activates these pleasure circuits and triggers the release of dopamine. By monitoring brain activity with fMRI, researchers have found that the medial forebrain, nucleus accumbens, amygdala, and orbitofrontal cortex—all part of the brain’s pleasure networks—become active during video gaming. Interestingly, activation of these regions during video gaming is much stronger for men than for women. (This may reflect the design of the games in general, however, which tend to be targeted toward males.)

Anita Sarkeesian, a video gamer who writes critically of the violent sexual degradation of women in video games, was forced to flee her home after she was hounded by violent threats of rape and murder because of that criticism. In October 2014 she abruptly canceled her scheduled speaking appearance at Utah State University after someone threatened a mass shooting at the event.

“There’s a toxicity within gaming culture, and also in tech culture, that drives this misogynist hatred,” she says. Concerns over the harmful effect of violent video games on children and adults drives movements for new legislation to restrict violent and sexual content in video games, but these debates perpetually revolve around the eternal question of whether art motivates human behavior or reflects it.

What these facts show is that sex and violence are linked in the human brain, because both activities strongly stimulate the brain’s reward and pleasure systems, especially in males. In studying aggression in mice, Craig Kennedy, professor of special education and pediatrics at Vanderbilt University, provides evidence that violent aggression can be addictive because it activates the dopamine reward system. In his experiments, an intruder male mouse was placed into the home cage of another male mouse, which immediately provoked an aggressive attack. This is the Environment trigger of violence, but here is the surprising finding: When the researchers then trained the home mouse to press a lever to permit the intruder mouse to return to the cage, after fighting with the intruder, the mouse would press the button to invite another fight, just as if it were delivering cocaine or another drug that stimulates release of dopamine in its brain. When the researchers blocked dopamine action in the mouse’s brain with a drug, the mouse stopped pressing the button to seek another battle.

“Aggression occurs among virtually all vertebrates and is necessary to get and keep important resources such as mates, territory and food,” Craig Kennedy said in a news report on his research. “Almost all mammals are aggressive in some way or another. . . . It serves a really useful evolutionary role probably, which is you defend territory; you defend your mate; if you’re a female, you defend your offspring.”

But this brain circuitry can lead the brain to seek out violence, to pick fights for no apparent reason other than to derive satisfaction of the rewarding feeling that comes from the aggressive encounter. Interestingly, the neurotransmitter serotonin is involved in both sexual gratification and violence.

The US armed forces have been scandalized by persistent news stories about sexual assaults on enlisted women. Reported sexual assaults in the US armed forces surged 50 percent in one year (2013–2014). According to the Pentagon, the Marine Corps recorded an 86 percent increase in sexual assault reports in 2013. The Army saw an increase of 51 percent, compared with a 46 percent increase in the Navy and 33 percent increase in the Air Force. In all, 5,061 people reported being sexually assaulted in the armed forces in the year 2013, and the majority of victims were younger than twenty-five.

The scandal provoked outrage among many in Congress and among the general public. But sexual abuse in the United States is not a problem that is unique to the military. The same year, fifty-five colleges and universities reported having open sexual violence investigations under way; this list included the most elite private schools in the country as well as public institutions. This led the White House to launch a task force to find ways to address the problem of sexual assault of undergraduate women on the nation’s campuses. “Colleges and universities can no longer turn a blind eye or pretend rape and sexual assault doesn’t occur on their campuses,” Vice President Biden said in announcing the White House effort.

But the problem of sexual assault is not confined to the military or colleges. A survey published in a scientific journal in 2014 found that more than half of respondents reported that, as female scientists, they had experienced sexual harassment or sexual assault in the workplace. A surprising 64 percent of the female scientists reported being sexually harassed, and 20 percent stated that they had been victims of physical sexual assault in the workplace. Younger women are at highest risk, with 90 percent of the female scientists who were assaulted being trainees, undergraduate, graduate, or postdoctoral students. These three environments (military, universities, and laboratories) and the people who inhabit them differ dramatically. What they have in common is an abundance of young women working together with men.

Self-Harm

“I have cut myself only once in the last twelve years.” The words that come from the highly successful, intelligent, and extremely motivated petite blond woman shatter the impression that crystallizes from her outward composure.

“I started self-harming at seventeen with a pencil-sharpener blade. My home was incredibly difficult and there were young children that needed as much protection or buffering as I could give them. I would hurt myself to release the tension, so that I could go back and carry on absorbing as much as I could. I was alone and so learned that way of coping with my own emotions. I continued to self-harm, but by then it was more serious as I was using a scalpel until I was thirty.

“I can feel that it is building up—can feel it coming. It will reach a pitch where it almost cannot be ignored, like going to the toilet, like being absolutely starving. It just gets to a point where it has to be acted on. Something will happen and that will trigger something. . . . Rage can be a huge part of it.

“The really crucial part of it is that self-harm works like no drug I have ever seen. It brings people down. They are softened. They feel better. They are calm. And depending on some degree to the degree of the injury, that [relief] can persist for quite a few days.”

“Does this feeling happen after someone responds?” I ask her, wondering if perhaps the frenzy of people responding to the medical emergency might fulfill a possible starvation for personal care and attention.

“No. Just the act of doing it, and sometimes seeing the wounds. I think it can produce a shock. A genuine biological shock—drop in blood pressure. There is something very validating, I think, about having seen [the bleeding cuts]. That degree of injury—that is self-validating: ‘This is how bad it is. Look what’s happened.’”

According to a recent study, 1 in 12 young people, mostly girls, engage in self-harming, such as cutting, burning, or taking life-threatening risks. Many carry this self-destructive behavior into adulthood. Self-harming is one of the strongest predictors of who will go on to commit suicide.

“It’s literally like a bomb is going to go off in your head,” the young woman explains. “Something will happen; it reaches a pitch where serious self-harm has become inevitable. I have contempt and rage for myself. When I hurt myself the thoughts are that I should have known better than to ever try and make it different. That I am so stupid. What did I expect? I am nothing. I should know that by now. In that space I hate myself for trying and I hate myself for hoping. It’s pretty bleak. When I am self-harming I am in a cold rage. I do it. Look at it. Judge if it’s enough and then carry on until I am literally sated, totally soothed. The peace I feel is brilliant. I can manage anything then.

“It would be very interesting to know what has happened in my brain! It feels absolutely dramatic. (It looks pretty dramatic too!)”

Her question could be easily answered with an fMRI brain scan, but that will never happen. It is not ethical to harm people (or to let them harm themselves) simply to study the effects. That bright line in scientific ethics cannot be crossed. But there is little doubt what an fMRI would show. As has been discussed earlier, the sight of blood does induce a mild physiological shock response. The slowed heart rate, sudden drop in blood pressure, and increased tolerance to pain would indeed act instantaneously—faster than a drug—to squelch anxiety and stress.

But this is an act of violence driven by unconscious forces in a state of cold rage. The behavior does not come as a conscious decision within the cerebral cortex; it wells up from emotional unconscious circuits deep in the brain that control behavior by issuing powerful urges. To carry out an act of violence in a sudden rage state, one of the nine LIFEMORTS triggers must be tripped. Self-harm is not rational.

In addition to identifying the trigger of violence, other important questions about self-harm arise: Why violence and not some other behavior in response to the stress? Why is self-harm so common in adolescent years? Why are girls much more likely to engage in self-harm? To what extent does a child’s environment during rearing contribute to the violence directed at oneself?

People like the woman who shared her experience with me frequently describe the self-harm as being driven by an intense sense of shame or inadequacy. This falls within the Insult trigger of violence. Shame is a stressful emotion that develops from comparing yourself with others, or with your own expectations of your personal standards, and finding yourself inadequate. Shame is a personal insult. It is all about establishing your rank in society, and this explains why the behavior that is evoked is violence. Humans, as with other social mammals, are utterly dependent on society for survival. An individual’s place in the social organization is one of the most important factors in one’s quality of life and well-being. Most commonly, physical aggression is how rank in society is established in the animal world, especially for males.

Haley Peckham, a neuroscientist and psychiatric nurse trained in the UK, cares for children between the ages of twelve and seventeen in an adolescence public health ward. “We have a huge amount of self-harm/suicides. This is a common problem for adolescents.” The remainder of her patients are kids with drug-induced psychosis and others with personality disorders or apparent psychosis.

I asked her what causes the kids in her ward to snap aggressively and lash out violently against others or to inflict harm on themselves.

“Often it can be another young person in the ward getting attention, by which I mean—we have this thing called ‘code gray,’ which is an aggressive unarmed threat. We have lots and lots of them where we are. So what happens is, security turns up and nurses turn up and there is a lot of effort put into talking someone down. That can very frequently send off other kids into—not usually aggressive, but quite often self-harming-type behaviors. There can be many reasons for this, but it can be through feeling not important enough to get that many people to be able to come to you.”

“What types of people do this?” I ask.

“They are people who are very, very unlikely to become aggressive with other people. They are people who might find it very difficult to express their own needs, to be assured enough to ask for what they want, so they tend to be much more inhibited in that way. So it tends to get directed toward themselves. They wouldn’t think of hurting someone else. Nevertheless, if what they did to themselves, they did to someone else, they would be in jail.”

This explains why females more frequently direct their violent impulse in response to the Insult trigger toward themselves rather than toward others. A male, equipped biologically by evolution with physical strength and aggression, who experiences the same trigger of rage as the woman would more likely engage in a brawl. This brutish behavior is how a man will more frequently react to the Insult trigger of violence. This makes for male bullies and fistfights. Such men seek violence and direct it toward another man to achieve the same satisfaction and release of stress that a person experiences from self-harm. Blood, injury, and the “high” of overcoming social defeat provide the same physiological and emotional outcome.

“I’ve only ever had chairs thrown at me by boys,” Peckham says when I ask her if she sees a difference in snapping behavior between girls and boys in her care. “I think I am quite lucky because I am small. I’m gentle, and I am a girl. So I think that keeps me out of a whole lot of violence. There is nothing to be achieved in picking on me.

“I’ve been around much more self-harm with girls. Head-butting [against a wall], or often you can see that they are in this state—vibrating with needing to get something out, literally vibrating but not knowing what to do—pacing or just bashing things. If you can tolerate being around someone who is doing that, banging their head or punching, punching, and they are hurting themselves, that’s OK, but when you lay hands on someone, then you become fair game. They are trying very hard not to direct it to you and they are hurting themselves. Then you intrude on them hurting themselves, and then the violence can be directed at that person, or directed at the person who has triggered it or anyone who has witnessed the shame.”

This also explains why self-harm peaks in adolescents. Adolescence is a period of life when an individual is seeking to establish his or her place in society, and at this age one’s peer group is the most important aspect of their environment. Another critical environmental factor is their home life and upbringing.

“When you talk to these kids I hear so many tales of emotional, sexual, physical abuse. Of fractured families, of school bullying, Facebook bullying, and lack of—lack of nurture and good attachment,” Peckham says.

All of these environmental factors relate to one’s feelings of self-esteem and comparative success in family and social life. This is the period of life when the brain is being developed according to experience.

“We live in a different environment [from our evolutionary past where violence was necessary and appropriate for survival], but the pressures are still enormous; where shame is still . . . Look, everyone’s climbing, everyone’s competing. There is still huge pressure and huge competition and there are still people who are on a good cycle, where they have a good start and they can make their way, and there are other people who are absolutely flat-out trapped, and it really doesn’t matter how much effort they make, because they are pretty much trapped.”

Quite often, it is females who are inclined to feel trapped, because of social and biological factors.

A Guy Thing

Despite the enormous number of elements that enter into criminal violence, gender is by far the most important factor. Nearly all violent crime is committed by males. Crime varies greatly in different locations, but taking my state of Maryland as an example, the 2012 crime statistics reveal rage circuit triggers in action.

Police are able to identify the offender, charge them, and take them into custody in 55 percent of all violent crimes in my state. This is termed the “clearance” rate; the prosecution rate is significantly lower. For juveniles involved in violent crime the clearance rate is 13 percent, meaning that the vast majority of violent juvenile offenders are not identified and taken into custody.

Murder accounts for 1 percent of all violent crime in Maryland. Of the 228 murders in the state of Maryland that were cleared in 2012, 93 percent of the killers were male. Five percent were juvenile—that is, under eighteen—but young people do show up in significant numbers in this data: 45 percent of murder victims are between the ages of eighteen and twenty-nine. Handguns were used in 73 percent of murders; a knife was used in 13 percent. Contrary to what one might have imagined from television dramas and news reports, drug-related murders account for only 3 percent of the total. The rate at which family members are murdered is four times higher, 12 percent of total murders. Five percent of the murders that take place in families are committed by cohabiting husbands, wives, boyfriends, or girlfriends. Eighteen percent of murders are committed by acquaintances who are not family members. Strangers account for only 17 percent of murders.

Robbery is the most common circumstance leading to murder, but heated arguments are nearly as common. In half of the murder cases under investigation there is not enough information to determine what instigated the homicide. Consider that statistic: Half the time after someone’s life ends violently at the hand of another human being in murder we can find no reason for the death of the person.

We turn now to other violent crimes. Rape by force accounts for 88 percent of all rapes. Of those arrested for rape in 2012, 11 percent were juvenile, 60 percent black, 39 percent white (Hispanics included), and 1 percent Asian or American Indian. Fifty-two percent of robberies were committed on the street, while only 1 percent were bank robberies. Guns were used in 43 percent of robberies. Robberies are cleared in only 14 percent of cases involving juvenile offenders. The breakdown by sex shows the perpetrators are 89 percent male, 11 percent female, and 26 percent juvenile. Gender is again the most important factor in these crimes of violence.

Aggravated assault, in which one person causes severe or aggravated bodily injury to another person, shows similar trends. Aggravated assaults account for 58 percent of all violent crime. Fourteen percent were assaults with firearms, 27 percent were assaults with a knife. The difference between rates for these two weapons used in murders versus aggravated assaults likely reflects the greater lethality of firearms, thus putting the results of the violent attack in the murder category when a gun is used. When other weapons are used in assaults, 21 percent are with hands and feet, and 39 percent are with other weapons. The breakdown of persons arrested for aggravated assault is 76 percent male, 12 percent juvenile. Again, with respect to this chapter on sex and violence, these statistics show that most violent assaults are committed by males, and that being male is the factor, of all the factors measured, that is the most common among perpetrators.

The vast majority of domestic-violence crimes involve assault, with 16,269 assaults out of a total of 17,615 domestic-violence crimes reported in 2012. There were twenty-two murders in domestic disputes in Maryland in 2012. Most domestic assaults occur between six p.m. and one a.m., with a peak at eleven p.m. Thirty-six percent of domestic violent crimes are reported on Saturday and Sunday. Most occur on Sunday (3,360 out of 17,615). The victims are typically female—13,029 women assaulted out of 17,615 incidents of domestic violence (74 percent). The rates do not vary much by race, but most victims were between the ages of fifteen and forty-four (59 percent). The victim is typically a wife or female cohabitant living together with a male, rather than in an estranged relationship. Alcohol use was involved in 4,882 of the 17,615 cases of domestic violence in 2012—far from the majority.

In analyzing the circumstances that sparked the domestic violence, infidelity was by far the most frequent cause: the Mate trigger. Next were disputes involving offspring (Family trigger), followed by arguments over money and property (Resources trigger). Surprisingly the table of statistics shows disputes over television as a cause of domestic violence. Tussling over the telly generates more domestic disputes than gambling, sex, or violence erupting during reconciliation attempts. This can be taken as another reason to favor books over TV and may be a reason to keep the television out of the bedroom. The struggle over the TV is the Insult trigger of interpersonal dominance.

Evolutionary history and the physical differences between males and females account for the prevalence of violence committed by males. In a physical contest with much stronger males, females will likely lose. Females therefore would be wise to avoid direct physical battles with males and to use indirect methods of aggression instead, such as gossip and sabotage. This does not explain why there are so many male/male physical assaults and murders and so few female/female physical battles, unless the behavioral strategies females have had to evolve to cope with male aggression have resulted in differences in the female brain that support a different response to interpersonal threats other than violence. There is good neuroanatomical evidence for such differences in the male and female brain. Men’s brains are tuned like those of a predator, and women’s more like prey.

This is not to say that women are not capable of violence, as we saw in Sgt. Leigh Ann Hester’s battlefield bravery. Females respond to all the LIFEMORTS triggers of rage with rising internal anger and often violence, but some triggers are more powerful instigators of snapping in violence for men than for women. Certainly women will protect their young and family with violence if necessary. They will respond to a violent attack with violence to save their own life. Domestic violence and violence related to partners are common for women. “Hell hath no fury like a woman scorned,” as the saying goes.

Professor Stefan Andersson and his girlfriend Ana Trujillo spent most of the evening at a local taco restaurant where they shared a couple bottles of wine and a few tequila shots. Another man approached Trujillo at the bar and offered to buy her a drink. That sparked an argument between the couple (Mate trigger). The two left the restaurant but the argument boiled up into a fight in Andersson’s apartment around two a.m. Neighbors were awakened by the noise of fighting and furniture sliding over the floor. Trujillo fatally stabbed Andersson twenty-five times in the face and head with the heel of her five-and-a-half-inch stiletto shoe, killing him. “It looked like something out of a horror movie,” Assistant District Attorney Sarah Mickelson said. “There was so much blood, the police officer thought Stefan had been shot in the face.”

Trujillo claimed she acted in self-defense, but she was convicted of murder and sentenced to life in prison.

Female-on-female violence occurs between women who know each other in 88 percent of cases. It is most likely to occur in outdoor locations (60 percent) and in the presence of others (91 percent). A survey found that most of the women involved in this type of violence have experienced disorder in their lives, had limited resources, and were the victims of violence themselves in multiple relationships. Sexual abuse is a common source of psychological trauma for women and girls. In the United States, 18.3 percent of women have been raped or experienced an attempted rape; of which 12.3 percent were younger than age twelve when they were first raped, and 29 percent were between eleven and seventeen. These traumatic experiences often leave long-term psychological disturbances.

“Oh, yeah, women fight,” a coed told me. “Usually they fight over men.” Her four female friends all nodded in agreement. Their perception is supported by surveys showing that the primary cause for female-on-female violence is in response to gossip, male partners, and personal insults. Another study showed that fighting to protect a third party is also a common cause of female-on-female violence. The presence of bystanders increases the likelihood of intra-gender violence in situations where there is a public challenge requiring a response to save face. Being hit with an object or stabbed are the most common forms of female-on-female violence; guns are rarely used. Most incidents of female-on-female violence are within the same race (93 percent) and same age range. In a survey of females admitted to the emergency room as a result of female-on-female violence, 33 percent of the assaults were sparked by personal insult, 23 percent related to male-partner jealousy, and 22 percent related to negative gossip and rumors or in response to not being liked. Defending the reputation or physical well-being of friends and family constituted 17 percent of the cases of female-female violence. Jealousy about material goods or physical appearance also triggered females to fight each other, in 17 percent of the cases. Sixteen percent of female-on-female violence was related to using and selling drugs.

The LIFEMORTS triggers are clear in female violence even though the way the researchers tabulated the causes would lump and split some of them into somewhat different groups in calculating the percentages. The study shows that some factors that have been established for male violence, including low socioeconomic status, apply to violence committed by women as well. Aggressive posturing and aggressive action are thought to be necessary to survive in a threatening environment, which requires communicating a readiness to use violence to resolve disputes lest one become the target of victimization. That is, people reared or living in “rough neighborhoods” need to be “tough” in their behavior to avoid becoming a victim. Indirect aggression, such as rumor and gossip, are much more frequent among females than males, who rely more heavily on overt physical aggression. Low-income black women are particularly at risk for involvement in assault in the United States. This correlates with the socioeconomic factors that increase the risk of violence. According to a Centers for Disease Control and Prevention (CDC) study, 44 percent of lesbians will be physically assaulted by their partners, somewhat higher than the rate for straight women (35 percent), gay men (26 percent), and straight men (29 percent).

In June 2014, thirty-two-year-old Olympic gold medalist Hope Solo, a goalkeeper in soccer, was arrested for domestic violence for allegedly assaulting her sister and her seventeen-year-old nephew in a drunken, violent outburst. The cause of the argument was an insult. According to court documents, Solo told her nephew at the party that he was “too fat and overweight and crazy to ever be an athlete.” He responded by calling her an insulting name and walked away to another part of the house. Solo followed and attacked him. When her nephew’s mother tried to intervene, Solo attacked her as well. Hope’s lawyer claims that she is innocent. Insult, especially under the influence of alcohol, is a cause of violent rage for both sexes.

In a less violent example of female snapping in rage, in April 2015 ESPN television reporter Britt McHenry was caught on a security camera snapping in anger and berating a towing company clerk after her car was towed and impounded. In this case, it was the Resources trigger that caused McHenry to snap. In any other circumstance, having your car taken away without your knowledge would be robbery. What is interesting from the perspective of female-female aggression is how this videotaped scene provides candid insight into female-female aggression. McHenry snapped at the company clerk by insulting the woman’s status as a woman and her lowly position in society. Here are excerpts from the security-camera video:

“That’s why I have a degree and you don’t,” McHenry taunts. “I wouldn’t work at a scumbag place like this. Makes my skin crawl even being here.”

Launching into a personal insult about the woman’s appearance, McHenry says, “Maybe if I was missing some teeth they would hire me, huh?”

The employee responds with an insulting comment about McHenry’s dyed blond hair and the color of her roots.

McHenry snaps back, “Oh, like yours, ’cause they look so stunning, ’cause I’m on television and you’re in a [expletive] trailer, honey. Lose some weight, baby girl.”

After she was suspended briefly by the television network, McHenry offered this apology via Twitter on April 16, 2015, reflecting the remorse that so often follows snapping: “In an intense and stressful moment, I allowed my emotions to get the best of me and said some insulting and regrettable things. As frustrated as I was, I should always choose to be respectful and take the high road.”

Had McHenry known that her sudden rise in anger was the Resources trigger activated to engage in a fight to get back her rightful property, she might have been able to suppress her immediate reaction and use her influence to plot sweet revenge against the towing company. In fact, a month later, lawmakers in Maryland and Virginia proposed new legislation to protect consumers from predatory towing by the same company that impounded McHenry’s car and others in the region.

Sexual Violence in War

Sexual violence against women and girls in war has a long, ugly history that continues to the present day. On April 14, 2014, 276 schoolgirls in Nigeria were abducted by Muslim extremists, the Boko Haram terrorist network, for use as sex slaves. Abubakar Shekau, leader of the Boko Haram Islamist group, released a video admitting kidnapping the girls for slaves to use and sell in the “marriage market.” The heinous crime of rape is a tactic of war to terrorize and defeat the enemy. Since ancient times, rape during combat has been regarded not as a crime but rather as one of the spoils of war. For insight into the ancient Mate trigger of violence in Western society, one need look no further than to the most universally respected of all sources. Consider these lesser known Bible stories:

I will gather all the nations to Jerusalem to fight against it; the city will be captured, the houses ransacked, and the women raped.

—Zechariah 14:2 (NIV)

So the assembly sent twelve thousand fighting men with instructions to go to Jabesh Gilead and put to the sword those living there, including the women and children. “This is what you are to do,” they said. “Kill every male and every woman who is not a virgin.” They found among the people living in Jabesh Gilead four hundred young women who had never slept with a man, and they took them to the camp at Shiloh in Canaan.

—Judges 21:10–12 (NIV)

The people grieved for Benjamin, because the Lord had made a gap in the tribes of Israel. And the elders of the assembly said, “With the women of Benjamin destroyed, how shall we provide wives for the men who are left? The Benjamite survivors must have heirs,” they said, “so that a tribe of Israel will not be wiped out.”

. . . So they instructed the Benjamites, saying, “Go and hide in the vineyards and watch. When the girls of Shiloh come out to join in the dancing, then rush from the vineyards and each of you seize a wife from the girls of Shiloh and go to the land of Benjamin.”

. . . So that is what the Benjamites did. While the girls were dancing, each man caught one and carried her off to be his wife.

—Judges 21:15–23 (NIV)

Sexual violence against women that stems from regarding females as property is recorded in the Bible outside the context of war. Concubines were female slaves who functioned as a “secondary wife.” In addition, poor families could sell their daughters in dire times (Exodus 21:7–10; Judges 19:1–29). This practice was perpetuated to meet the sexual desires of males and also to cement political alliances.

Korean women were forced into prostitution by Japan during WWII to service the military men. Estimates range from 20,000 women to 200,000, including not only Koreans but women from many countries occupied by Japan during the war—China, the Philippines, and others. The women were incarcerated into several “comfort stations.” Approximately three-quarters of these “comfort women” died, and most survivors were left infertile as a result of sexual trauma or sexually transmitted diseases.

“In the ‘comfort station’ I was systematically beaten and raped day and night. Even the Japanese doctor raped me each time he visited the brothel to examine us for venereal disease,” a survivor of the forced prostitution testified.

Prepubescent girls were repeatedly raped by Japanese soldiers, those who fought back were executed, and the women served as many as twenty-five to thirty-five men a day. Rapes committed by Soviet servicemen during combat operations and during subsequent occupation in WWII are well known. Estimates of the number of German women raped by Soviet soldiers range up to 2 million. In many cases, women were victims of repeated rapes, as many as sixty to seventy times.

Insight from Our Distant Relatives

Why are humans typically monogamous? Only 5 percent of other mammals have a single mating partner. From a Darwinian perspective, having more female partners should be an advantage to a male by spreading his genes through many more offspring. In studying DNA of a variety of mammals, researchers have recently suggested two explanations for human monogamy. “Females changed their diet to foods of higher quality that were clumped, and defended that food more aggressively,” University of Cambridge zoologist Dieter Lukas says, referring to the consequences of developing agriculture. This led to large, exclusive territories becoming associated with individual females. These territories became too big for one male mammal to successfully defend more than one of them.

Infanticide is another factor, as supported by studies on primates. “Infanticide is a real problem, particularly for social species,” University College London anthropologist Christopher Opie says. The large brain of humans takes years of childhood to develop, giving more opportunities for a rival male to kill the child and impregnate the female (an evolutionary advantage from a Darwinian perspective of survival of the fittest). Thus, male primates that stick with their child, and therefore with one mate, have an evolutionary advantage by warding off intruding males. From this perspective we can see the distant roots of the Mate, Environment, and Family triggers of defensive rage.

In their 1996 book Demonic Males: Apes and the Origins of Human Violence, researchers Dale Peterson and Richard Wrangham consider male-female relationship violence through studies on primate behavior. Male chimpanzees fight even when in captivity where they are provided with ample care and food. Their battles establish a social dominance, and the alpha male reigns supreme. There are complex social coalitions formed among rival males to attack the alpha male. The authors describe the death of an alpha-male chimp one night by a combined attack by three male rivals. In the morning the zookeeper found several of the alpha male’s toes, fingers, and both of his testicles on the floor—bitten off in the attack for dominance.

Among the aggressive behaviors of primates that have been passed down to us are aggression for social dominance (especially among males) and the ferocious defense of territory by both males and females. The sexually distinct bodily features of many male animals, such as horns and tusks, exist for combat between rival males to establish social dominance and for the aggressive acquisition of females for mating. These battles are ritualized contests where most mammals defeat the rival without battling to the death, but in chimpanzees, battles to the death do occur, just as in human conflicts.

Peterson and Wrangham conclude that there is something about the apes that specially predisposes them to violence. Sexual violence occurs in orangutans, and male gorillas kill infants frequently. Female orangutans, who must care for infants for eight years, prefer larger, aggressive males as partners. Some matings of orangutans are so violent they are also termed “rape” by the British researcher John MacKinnon, who has observed them in their native habitat. Applying the term “rape” to animal behavior is problematic, but there is no doubt that the matings are forced by the male using extreme aggression. “The females showed fear and tried to escape from the males, but were pursued, caught and sometimes struck and bitten.” By some accounts, one-third to 88 percent of orangutan matings in the wild involve aggressive attacks by males that drive the females into submission.

Other primates use violence in mating as well; for example, Jane Goodall has categorized violently aggressive matings as “rapes” among chimpanzees.

One extraordinary account of a violent mating by an aggressive male orangutan that Peterson and Wrangham describe in their book was unquestionably a rape, because the victim of the sexual assault was the camp’s Indonesian cook. The cook screamed for help. “[She] fought the ape with every ounce of her strength, beat him with her fists, attempted to ram a fist down his throat, but with no effect. . . .The cook stopped struggling. ‘It’s all right,’ she murmured. She lay back in my arms, with Gundul [the male orangutan] on top of her. Gundul was very calm and deliberate. He raped the cook.”

Peterson and Wrangham argue that rape cannot occur if social alliances exist to combat it. In orangutans the females are solitary, whereas female gorillas live in troupes that protect them from strange males, making gorillas safe from “rape.” There is a rich literature on evolutionary psychology based on studies of primates and other social mammals that provides compelling insight into human behavior, but this is outside the domain of this book on the neuroscience of sudden rage and aggression. The important point is that our brains and behaviors today evolved from our prehistoric hominid ancestors, and before that time from nonhuman primates who have brains that are so similar to ours anatomically that the nonhuman primate brain, down to the cellular level, is almost indistinguishable from the human brain. For this reason, most countries have banned brain research on chimpanzees for ethical reasons.

Tangled Neural Networks of Sex and Violence

“What I call the four F’s: feeding, freezing, fighting, and . . . mating,” quips neuroscientist David Anderson of Caltech, introducing his research on the neurocircuitry of sex and violence at a scientific meeting. Sex and violence are linked in culture, seen throughout the animal kingdom, and evident in the extreme as pathological dysfunction. Dating tips on the website Match.com list teasing and physical aggression as one of the sure signs to women that a guy likes you: “The boy at school who kept teasing you or punching your arm; he might have been crazy about you.” The work of Anderson and others, using advanced methods that have been developed only in the last few years to study neural circuits, shows that there is a neurobiological explanation for the link between these two behaviors. The brain circuits of sex and violence are intertwined.

Feeding, freezing, fighting, and “mating” are all powerful unconscious urges controlled by neural circuits in the hypothalamus, so the answer to the intriguing question of whether there’s a neurobiological basis for a relationship between sex and violence is likely to be found in this deep brain region. New research teasing apart these hypothalamic circuits reveals that different automatic behaviors, such as different responses triggered by different types of threats, are controlled by separate circuits in the hypothalamus (as we explored in chapter 9), but an exception is found in the apparent connection between violence and sex. More perplexing is that these two contradictory behaviors of love and hate are seemingly polar opposites. How could these contradictory behaviors possibly be controlled by the same set of neurons in the hypothalamus? Both powerful behaviors are activated by different stimuli in different situations and they serve different purposes. An alternative explanation could be that there are two separate circuits controlling these diametrically opposed behaviors (“love and hate”) and they are somehow cross-wired in certain circumstances? The search for answers to the neurocircuitry of sex and violence is uncovering part of the neural mechanism behind the Mate trigger of violence.

Consider this important fact: From a behavioral and physiological point of view there are common features in both aggression and mating. Both behaviors evoke intense states of arousal—indeed, the most intense states of arousal possible. At some level, then, the two behaviors must activate similar neural circuits to evoke such similar extreme states of arousal. Also, both behaviors, when the outcome is successful, evoke potent feelings of reward. Finally, in the natural world, aggression and mating are interrelated behaviorally, and both are co-regulated by similar environmental influences and by the internal state of the body. Physiological states that arise during mating also promote aggression. Male animals are more aggressive at the mating time of the year, when females are ovulating. Most fatal encounters between people and moose occur during mating season, when bull moose become aggressive in seeking out mates and are engaged with other males in contests for mates. In mice it has been shown that prior sexual experience can increase aggressiveness. Seasonal differences, environmental context, and hormonal states mutually reinforce both aggressive and mating behaviors, so similar brain systems are involved in both behaviors.

It has been known for some time that regulation of mating behavior is controlled by the same part of the hypothalamus that Walter Hess identified with his electrical stimulation experiments on the cat brain in the 1920s, the hypothalamic attack area. This brain region encompasses the medial hypothalamic nuclei. But electrical currents from an electrode can also activate nerve fibers that pass through the site of stimulation, so the neurons controlling sex or violence might actually lie in different parts of the brain and only become artificially activated as they pass by the electrode. Alternatively, the neurons controlling sex or aggression might be located in the same “attack” region of the hypothalamus, but the two opposing behaviors could be controlled by different neurons mixed together like salt and pepper. These perplexing questions have puzzled scientists for decades, but very recently neuroscientists have discovered the answers.

Using the method called c-Fos staining described in chapter 9 to identify neurons that have been active just before examining the brain tissue, Anderson’s research team identified individual neurons that became active after a mouse engaged in an aggressive encounter with another mouse or, instead, had just engaged in mating behavior. They found that the same set of neurons in the medial hypothalamic nucleus became activated by both behaviors. This would suggest that sex and violence are controlled by the same hypothalamic neurons. But in looking at the tissue alone, it is not possible to determine if the very same neuron that had been activated by sex was also activated by fighting, or whether two different types of neurons handle each behavior separately. The two types of neurons are clustered together in the same brain region. To make the distinction, it would be necessary to monitor the activity of a single neuron during both fighting and mating. This remarkable experiment has been done.

Electrophysiology has advanced greatly beyond the pioneering studies Hess performed with his slender wire used to stimulate the cat’s brain. Today researchers use microcircuit fabrication techniques designed for integrated circuit production to make microelectrode arrays, looking something like microscopic combs. Once implanted into the brain these electrode arrays tap into a dozen or more separate neurons at once. Moreover, these precision microelectrodes can be implanted in the brain of a freely behaving mouse and studied for days. Dayu Lin, while working in Anderson’s laboratory, implanted such microelectrodes into the brains of mice to record electrical signals in individual cells in the medial hypothalamic nuclei as the mice went about their normal activities. What this research found was that some hypothalamic neurons became active during fighting, and others were active during mating, but many of the very same neurons were active during both mating and fighting.

Strictly speaking, this experimental result revealing that many of the same neurons are turned on in the brain’s attack region during both mating and fighting does not necessarily mean that the neurons are critical for either behavior. They just might be responding to some aspect of brain function or brain state that is present during both sex and violence, such as arousal. To test the very important question of causation, the researchers used genetic engineering to turn on or turn off these specific neurons using a drug. When these neurons of sex/violence were silenced, mice no longer engaged in aggressive behavior toward an intruder mouse placed in their home cage. This shows that these neurons are necessary for violent attacks, not just a by-product of them. However, mating activity was not at all affected in these mice when those neurons were silenced. Perhaps the fourth F is just more important than the third?

Follow-up research showed that there were in fact two different types of neurons in the medial hypothalamic nucleus that became activated during fighting and mating; about 40 percent of these neurons identified by c-Fos staining had a membrane receptor for the hormone estrogen. (Estrogen is present in both males and females, although females have higher concentrations.) The previous approach of turning off both sets of neurons in the brain region (with and without estrogen receptors) might have gummed the works in a way that would not happen naturally, so the researchers tried a more precise approach.

Optogenetics allows activity in individual neurons to be turned on or off by light stimulation. If a gene (for example, one making estrogen receptors) is expressed selectively in one type of neuron, scientists can use genetic engineering to insert an artificial gene into that particular type of cell. The artificial gene that is introduced makes a membrane protein that either excites or inhibits the ability of the neuron to fire electrical impulses (action potentials) when a blue laser is turned on. The light can be delivered to select spots in the brain by using slender fiber-optic cables implanted in the brain while the animal is freely engaged in its normal behavior, as was described in chapter 9 in studies on the fear circuitry in the hypothalamus and limbic system.

When the researchers switched on the blue light to activate the neurons that had the estrogen receptor, the mice began to fight. The battles ceased when the laser light was switched off or when scientists specifically inhibited firing in those neurons. This shows convincingly that the neurons with the estrogen receptor on their surface have a causal role in both initiating attack and in maintaining fighting. Again, mating behavior was not affected.

Thus far, the results would lead to the conclusion that aggression and sexual behavior are controlled by different sets of neurons mixed together in the ventral medial hypothalamus, but that different neurons in this region control either fighting or mating. But if this is so, where are the neurons driving sex? The next experiment provided a surprising answer.

If, rather than blasting the neurons with a strong laser beam, the researchers carefully increased the brightness of the laser, like turning up a dimmer switch, they found that such low-intensity stimulation of the exact same neurons that caused fighting now caused mating. So powerful was this control over the animal’s behavior that weak stimulation of the neurons provoked mating behavior toward an intruder placed in the cage, rather than an attack, regardless of whether the intruder was male or female! This astonishing result means that all the various and complex sensory and emotional signals that go into deciding whether to mate with another individual, act through this common decision point in the ventral medial hypothalamus. By increasing the intensity of stimulation while the mouse was engaged in mating behavior, researchers found that they could switch the behavior from mating to fighting. Although it is dangerous to anthropomorphize from animal behavior, the videos of this experiment leave the poor female looking very perplexed as mating or fighting is interrupted or initiated by scientists increasing or decreasing the intensity of the laser beam. So the same neurons in the hypothalamic attack region control both violence and sex, but it is the level of activity in these neurons—both the number of neurons activated in the circuit and the intensity of activity in the individual neurons themselves—that determines whether the behavior will be mating or aggression. Perhaps the intense arousal at the jubilant celebration in Tahrir Square provoked a combination of violence and sexual behavior in the minds of some groups of men in the square.

This newly discovered neurocircuitry provides important new insight. Parallels between these animal studies and some normal and abnormal human sexual behavior that involves an interaction between aggression/pain and mating (from “rough sex” to deviant sexual behaviors) become apparent.

A team member in major league baseball shared a secret that some baseball players use to exploit the connection between aggression and sexual arousal. “I know players who, before their plate appearance, they’ll go in and they will look at pornography right before they go to the plate. They do this in an effort to have a kind of adrenaline boost or something. Let’s call it an animalistic type of approach to the ‘at bat.’”

The intriguing difference between these neurons that have receptors for estrogen means that other factors in the body can influence the general level of activity in these neural circuits. The complex set of factors in our environment—season, hormonal state, motivation, arousal, inhibition—all influence both aggression and mating behavior. Thus, the split decision to fight or flee, or to mate or attack, depends on the complex set of factors influencing the general level of neural activity in these circuits. We will return to this interesting question of setting the threshold for triggering a snap response in chapter 12. In my case with the attack in Barcelona, the question of whether I would have acted the same way toward the pickpocket on a different occasion or if I would always act in the same way in the future is answered by these animal studies: no. The split-second decision to snap aggressively in defense or for any other reason is set by a complex combination of situation-specific environmental factors and internal states of stress, arousal, or physiology in the body at the time. Clearly this must be the case, because such powerful behaviors with such significant consequences must be highly regulated and matched appropriately to the circumstance and bodily state. Similarly, in cases of snapping inappropriately with violence, as in Ray Rice’s case when he knocked his then girlfriend unconscious in an elevator, we can extrapolate from animal studies that the neurons in the ventral medial hypothalamus of Rice’s brain had been strongly activated, most likely in part by internal and external stresses that had revved up these circuits before he entered the elevator. Like the laser beam of increasing intensity, factors in combination overstimulated these circuits to provoke a sudden aggressive response.

So the environment and internal states strongly influence sex and violence through this hypothalamic nerve center. One’s environment during rearing or childhood influences these circuits as well, and also the strength of cortical circuits that regulate the neurons that drive sex and violence in the hypothalamus. This contributes to understanding at a cellular level why children raised in an environment where domestic violence occurs will be more likely to exhibit those same behaviors as adults. This is also why, as is evident in many places around the world, social environments that tolerate sexual aggression and violence against women create a vicious vortex that drives sexual brutality against females.

His-and-Hers Brains

According to UC Irvine neuroscientist Larry Cahill, an expert on differences between male and female brains, “Sex differences exist in every brain lobe, including in many cognitive regions such as the hippocampus, amygdala and neocortex.” In addition to anatomical differences between the sexes, functional studies show that the brains of men and women operate differently in several respects; that is, different brain structures are engaged in the brains of men and women for certain tasks. Performance in a given cognitive task may not differ between the sexes, but men and women are sometimes using different strategies to achieve the same result. Finally, there are numerous chemical differences in neurotransmitters between the sexes, not to mention the obvious hormonal differences. Hormonal fluctuations throughout a woman’s menstrual cycle are known to have striking effects on the cellular anatomy of parts of the brain (notably in dendritic spines), on cognitive performance such as verbal and spatial memory, and emotional states. The incidence of mental and neurological illnesses differs greatly between the sexes; for example, women have a much higher incidence of multiple sclerosis, depression, and fibromyalgia, but men have a higher incidence of schizophrenia and ADHD. This is clear evidence of important underlying differences in anatomy and function of the male and female brain.

Unwholesome family life can alter development of threat-detection circuits in the brain of young girls that persists into adulthood and predisposes women to developing mood and anxiety disorders as adolescents and young adults. Boys are also negatively affected by family stresses during childhood, but the lasting effects on their brain seem to influence only one of two neural circuits controlling response to threats, anxiety, and fear.

Recent neuroimaging research in several laboratories has shown that the wiring of a child’s brain is permanently altered by abuse and other stressful experiences early in life. The earliest research concerned children who were exposed to severe sexual abuse, but more recently, seemingly less harsh stresses have been found to alter the wiring of specific circuits in a child’s brain, such as verbal abuse from their peers in middle school. Such children suffer greater psychological problems as adults, and those problems can be traced to the differences in brain circuitry. A recent study by Ryan Herringa and colleagues at the University of Wisconsin followed a large group of children as they grew up, and found that girls are especially vulnerable to maltreatment in childhood; moreover, the maltreatment they experienced was comparatively subtle. Stressful family life—for example, financial stress or poor parenting—alters the development of threat-detection circuits in the brains of boys and girls. Thus, the young brain is very sensitive to stresses in family life; severe criminal-level abuse of children is not required to cause these effects.

As was described in chapter 9, threat detection involves interaction between three brain regions. The amygdala, deep inside the brain, detects novelty and danger in the environment and learns quickly to respond to and avoid threats. The amygdala therefore regulates our emotions of anxiety and fear. The hippocampus, located near the temples of the skull, is crucial for mapping our environment, forming memories of events, and learning the context of when experiences, including threats and stresses, are likely to be encountered. The prefrontal cortex, beneath our forehead, is the higher-level cognitive region of the brain that can evaluate complex information to make decisions and direct our attention and behaviors appropriately. This part of the brain is the last region to develop and in humans it is not fully developed until the early twenties.

Using fMRI, Herringa’s study found that boys experiencing family stresses early in life had weaker functional connections between the prefrontal cortex and the hippocampus, but girls who experienced the same stresses developed weaker connections between the prefrontal cortex and both the hippocampus and amygdala. Girls thus suffer a “double hit.” These changes in brain circuitry correlated with the level of psychological problems the individuals experienced in later life. These differences were measured while the children were in a brain scanner simply engaged in their own thoughts. This technique measures the brain’s “resting-state” functional connections, rather than pinpointing specific parts of the brain that become activated by a particular stimulus. The method tells researchers how the brain is wired rather than what parts of the brain are engaged in specific cognitive activities taking place at a specific point in time.

The explanation for the differences between boys and girls seems to be that different brain regions develop at slightly different times in everyone, and there are differences between the sexes in brain maturation just as in body maturation. Stress and abuse affect development of brain circuits most strongly during the period when a circuit is forming and maturing. This is why traumatic events—for example, combat experienced by military personnel—do not have the same effect on an adult as they have on a child.

Since the hippocampus provides context, this enables a person to experience fear in the appropriate environment rather than being anxious and fearful everywhere. “Females may have greater fear/anxiety responses generally following maltreatment experiences,” Herringa observes, because these girls have reduced connection to the amygdala as well as to the hippocampus. One of the changes Herringa would expect in these girls is that they would be more likely to suffer PTSD after traumatic experiences as adults. “Childhood maltreatment is a significant risk factor for adult PTSD,” he says, and these connections in the brain’s fear circuits are known to be involved in PTSD.

The changes in brain wiring caused by maltreatment in childhood seem to be the brain’s way of coping with the hostile environment. “This could very well be adaptive in a stressful or threatening environment but may also come at a cost of increasing risk for anxiety and depression [as adolescents and adults],” Herringa explained in an email.

These new insights offer possible new gender-specific treatments for anxiety and depression. “For example, a therapy involving contextual safety vs. threat learning could be helpful for both sexes,” Herringa says. This treatment would allow a person to realize that their feelings of anxiety and fear are not appropriate to normal situations. Both boys and girls showed decreased connectivity to the hippocampus after maltreatment, so “extinction therapies” using context to reduce anxiety and fear could be helpful to both sexes. An example of such a therapy would be having a boy or girl who suffered a traumatic experience in a particular location return to that location repeatedly with supervision under safe conditions, which should work to rewrite the memory of the trauma associated with that particular location. But even without rewiring from hostile experiences in early life, the brains of men and women in general operate differently under stress.

“There is this pattern across five or six labs,” Larry Cahill told me on a visit to my laboratory. “When you stress a male there is a tilt towards the right hemisphere in the amygdala activation.” In females under stress, the left amygdala becomes activated. This was seen in fMRI scans. What these scans cannot show (because imaging takes several minutes) is that this sex difference in using either the left or right amygdala to respond to a sudden threat happens in a split second. Cahill discovered this immediate response by flashing his subjects pictures, some of which showed emotionally charged stressful images, while recording the brain-wave activity from the left and right cerebral hemisphere in both men and women.

A brief explanation of brain waves that are evoked by sensory stimulation will be helpful in understanding what Cahill found. When a signal from the eyes (or any other sense) reaches the brain, the arrival of the electrical event causes a ripple in ongoing brain-wave activity. This ripple of electrical activity in the brain is called an “evoked potential,” because the brain-wave response was evoked by a sensory stimulus. But subsequent waves of brain activity ripple out after the initial tsunami of electricity reaching the brain from the senses. These “after-effect” waves are even more intriguing. These electrical signals represent the brain networks processing or “cogitating” unconsciously, in a sense, on the event that has just occurred. Most of what constantly assaults our senses flows through our mind as background noise, but any sudden unexpected feature in our environment instantly grabs our attention. This happens because we are not able to consciously perceive all of the ongoing sensory input to our brain, but our unconscious mind is in fact doing just that—constantly monitoring everything—looking for anomalous events in our environment of such significance that they warrant being elevated to a higher level of awareness or triggering an immediate reflexive reaction.

Say a gruesome picture of a car wreck suddenly flashes on a screen during a series of otherwise tranquil images. That anomalous image sends a shudder through our awareness and we immediately attend to that image, remembering it clearly, while the various other tranquil pictures fade out of consciousness and are lost from our memory. When this happens—that is, when a novel feature suddenly grabs our attention—the EEG recording of our brain waves shows a sudden characteristic rise in activity, called the P300 wave. This wave is called P300 because it is a positive (P) rise in brainwave voltage and it peaks 300 milliseconds (only one-third of a second) after the novel stimulus. This P300 wave is not evoked by any of the tranquil images. Intriguingly, the P300 wave reflects not the simple transmission of sensory information to the brain but rather the brain processing the significance of the sensory input that has come in. That is, the P300 wave reflects the instantaneous and unconscious decision to engage our attention and orient our cognitive function toward the novel stimulus. If someone were to say to you, “I take my coffee with cream and dog,” a P300 wave would erupt in your brain from the unexpected input “dog” instead of “sugar.” Did you “feel” the P300 wave rise in your own brain just now?

When I felt the thief’s fingers delicately slip into my pocket to snatch my wallet in Barcelona, a P300 wave would most certainly have surged in my brain like a huge breaker rolling in amid tranquil surf. That anomaly in my sensory world tripped an urgent alarm within one-third of a second, fully engaging my brain and body and orienting my attention to address the threat, causing me to reflexively grab the unseen robber by the neck as he turned to dash off with my wallet.

But male and female brains operate differently under stress, and the P300 wave proves this in Cahill’s experiments. “In the first 300 milliseconds of a scary thing coming into view [like a gruesome picture of a car wreck] there is a right lateralized P300 response in [the] male and a left lateralized P300 in the female.” By this, Cahill means that the right cerebral cortex gets activated in males under stress and the left cortex gets activated in stressed females. Who could have predicted that the brains of men and women would cleave in such a major way under pressure? What is the possible significance of this differential lateralization of brain activity?

The answer, Cahill suspects, has to do with differences in information processing between the left and right hemisphere. “Gist versus detail,” he says. “The right hemisphere of the brain is better at processing lower-frequency [less detailed], bigger-picture—seeing the forest but not the trees. The left hemisphere is geared towards processing the higher-frequency details. Males and females are doing both [when not under stress], because both males and females need gist and detail processing to survive.”

Why should the two halves of our brains operate so differently? “Detail by definition gets in the way of gist, and gist by definition gets in the way of detail,” he says. The elegant solution seems to be that the brain divides up the problem to permit independent analysis of detail by the left hemisphere and big-picture gist by the right hemisphere. The left brain is breaking down the problem analytically and the right brain is gathering diverse information to assemble a comprehensive picture of what is going on. This is how the human brain solves the contradictory challenge of perceiving detail and at the same time grasping the big picture. But in times of stress, brain function in men and women suddenly works differently.

“What happens when things get stressful, when things get emotional?” Cahill asks. “The male brain, for reasons that I don’t understand, is busy processing the gist of the situation [using the right hemisphere], and in women the left hemisphere is busy processing details.”

“During that stressful situation in Barcelona,” Cahill explains, referring back to when Kelly and I were being pursued the gang of robbers, “your brain was tilting more towards a larger-scale strategy, whereas hers was tilting towards a higher-frequency detail analysis.”

It was true in our case; Kelly rapidly picked out the criminals in the crowd amid the complex barrage of information we were confronted with in that foreign city, whereas I was looking at the forest, devising strategies to escape or fight.

To understand this difference in left-right/male-female brain function under stress, look quickly at the image below. What is the first thing you see?

Men under stress will tend to see a large letter S, whereas women under stress will immediately see a dozen dollar signs. A woman’s brain under stress shifts to activate the left cortex through her left amygdala, whereas a man’s brain under threat or stress shifts to engage his right amygdala. Since you are presumably not under stress at this moment, both your left and right amygdala are being activated equally by the image to allow your brain to both encompass gist and discern detail, but in times of stress or sudden threat, what you see will depend on your sex. On average, the two sexes cleave into specialized left- and right-brain function under stress to take either a helicopter view of the situation or get down in the weeds and analyze the details.

It is interesting to speculate why we have this sex difference in brain function. “The best answer I have for that is that sex selection across many species in the female tends to be more detail-oriented than does the male,” says Cahill. Think of female birds evaluating potential mates by subtle differences in their plumage or the performance of their courting behavior. “Two rams going bam! batting horns—there’s nothing subtle about it. In general the face literature [fMRI studies of brain responses to different faces] indicates that the female is better at picking up the emotional details than is the male.” This is only Cahill’s best hypothesis, he emphasizes, and there may be other factors involved in this sex difference in brain function under stress.

“There is strong indication that sex hormones are playing a role in stress response,” he says. “There are different stress effects related to the menstrual cycle. They are generally potentiated in women during the high-hormone luteal phase of the cycle. Stress responses are also clearly blunted in women who are on hormonal contraception.” Factors influencing triggers of rage will be considered in chapter 12, where research will be presented showing that hormonal factors have a major influence on brain function, threat detection, and snapping. What is clear from these studies is that the anatomy and function of male and female brains differ, and the sex differences are pronounced in circuits that detect and respond to threat. This neurobiology results in a partnership between males and females that is far more powerful than either sex alone.

What Women Want

She’s checking out your online profile.

“I am a scientist who enjoys bird-watching and canoeing.”

Interesting! she thinks.

Then she scrolls to the next profile—another scientist:

“I enjoy whitewater kayaking, and I study alligators in the wild.”

She passes on you with your canoe, and in eager anticipation sends the kayaker an electronic “wink.”

This, according to a study by psychologist John Petraitis, is what most women will do, but why?

John Petraitis limped painfully into his office with his left foot in a black knee-high Velcro cast. His right wrist was wrapped in a matching black cast to stabilize his thumb tendon, recently repaired by surgery.

“Skiing deep in the trees makes me come alive,” he says enthusiastically, gazing at the gorgeous snow-covered mountains surrounding his office in the Department of Psychology at the University of Alaska at Anchorage.

That explains the snapped Achilles tendon and hand surgery. Many guys are drawn to danger. Whether it’s aggressive skiing, motorcycle racing, or rock climbing, why are men and boys attracted to risky activities?

Part of the answer, according to Petraitis’s research, together with coauthors Claudia Lampman, Robert Boeckmann, and Evan Falconer, is supported by an experiment analyzing responses to online profiles in a mock electronic dating service. A lady’s choice for a first date may be swayed by factors extending back in time to when sharp stones, rather than Sharp computers, were the most advanced technology.

Petraitis was investigating the psychology of adult substance abuse when he was struck by the conspicuous differences in risk-taking behavior between the sexes. The highest rates of cigarette use, heavy alcohol use, binge drinking, and illicit substance use are seen in young people between the age of fifteen and twenty-five. Males have higher rates of all these risky activities, and males show up at emergency rooms in much higher numbers with traumatic injuries. They die at higher rates in outdoor accidents such as skiing and car crashes, and they are more often victims of homicide.

Partly these gender differences in risk-taking could be cultural. Boys are encouraged to display dominance and courage, accept dares, and take risks, whereas girls tend to be socialized to be cautious, social, and to show concern for others. Girls play with dolls. Boys play with “action figures.” But the preference for risk-taking behavior in males is seen across all cultures, suggesting something more than socialization may be at work in drawing men and boys to risky pursuits.

The research team suspects that gender-specific behaviors that have been favored over eons of evolution in the battle for survival have left their imprints in our DNA and they are still guiding our mate choices today. As every biologist knows, evolution is about sex. When it comes to sex, females are the ones who make the decision about mates. Males audition.

Consider the garish male peacock with such ridiculously showy tail feathers that actually make it harder for them to fly and easier for predators to spot them. The male birds strut about displaying their flashy tail feathers to impress the peahens in hopes of mating with them. The females, seeing the handsome bird with such a dangerously flamboyant plumage, think, “This guy must be amazingly fit to have survived with those dazzling tail feathers.” Genetic fitness, superior ability to survive in the face of dangers and handicaps, that’s what females are seeking in selecting their mates. A mate that can survive great risks must be exceptionally good at avoiding predators and acquiring food.

Many modern women will object to having their mate choices reduced to the pea-brained level of a bird, but the data paint a clear, broad picture. The researchers devised a list of 101 pairs of behaviors in a mock dating service in which each question paired a higher-risk option with a lower-risk choice. For example: Do you prefer a person who enjoys canoeing or one who goes whitewater kayaking? The choices included many more subtle risks, such as whether one prefers their salsa mild or spicy. The questionnaire was given to both men and women, and what the results showed is that women greatly preferred guys who engaged in the higher-risk behaviors. Guys, in contrast, did not show any preference for women based on their risk-taking profile.

But here’s the really clever part: Half of the paired questions dealt with the sort of risks that human beings would have faced thousands of years ago, and the other half dealt with modern risks, such as driving while talking on a cell phone. Neither guys nor gals cared a whit about modern risks in selecting first dates; in fact, these modern risks were likely to be viewed as unattractive and foolish.

Females couldn’t care less about a guy who enjoys sticking forks in toasters. There was no electricity in the Stone Age. The risk-taking behaviors women preferred are the ones that deal with overcoming gravity, dealing with wild beasts, crossing water, being indifferent to nasty or dangerous foods, and engaging in human conflict. These are what the research team calls “hunter/gatherer risks,” the kind of risks our caveman ancestors would have had to deal with. Modern risks, like playing with electricity, fooling with deadly chemicals, taking risks of identity theft, or driving without a seat belt, did not impress the ladies one bit.

Why is risky behavior so pronounced in young males? Again, the answer is sex.

“Female fertility is a rare commodity,” Petraitis explains. Males remain fertile into old age, but not so for females. “A twenty-year-old male competes with a sixty-year-old male [for attractive women].” The two age groups use different strategies to attract younger women. “Younger males are faster, stronger; they can bounce back from injury or adversity. Older males have more resources to provide for women.” So each group competes for young women in arenas in which they are more likely to win. “Young males are greater risk takers and adventurers to demonstrate their fitness,” he says.

He cites statistics on the biological facts of life to make his case. Males are fertile for sixty years, or 22,000 days. Females are only fertile half as many years, and they are only fertile twenty-six days per year, whereas males are fertile every day. Do the math and in an entire lifetime, women are fertile fewer than 850 days, compared to 22,000 days for men. Also, women’s investment in fertility is much greater, considering the nine months of pregnancy and years devoted to rearing a young child. Women have to be choosy.

Human behavior is complex, and one important insight, such as the hunter-gatherer risk appeal identified in this new study, cannot explain everything about male risk-taking. Petraitis suspects that males may also engage in risky activities to elevate status among other males. These new findings also do not explain why many women engage in risky activities, but he is devising experiments to investigate these questions.

For guys this research provides revealing insights into our male urge to risk life and limb in tests against gravity, water, fire, wild beasts, and dangerous food, but if you are thinking that taking risks is the way to impress women, you are missing an important point. Male fertility is cheap. If a peacock with an outrageous tail gets eaten, well . . . there are plenty of others. Likewise for the guy who gets gored and trampled by charging bulls in Pamplona, Spain.

Energetic and fit with a neatly trimmed graying beard, one might easily imagine Petraitis as the kind of guy who would eagerly attempt a 720 off the half-pipe to impress his lady (who happens to be one of the coauthors on the paper). But maybe he shouldn’t.

To Be a Man

The drug dealer, with shoulder-length dreadlocks and a handgun tucked in his waistband, was smoking synthetic marijuana and sipping Cuervo tequila with a cluster of other men on Martin Luther King Jr. Avenue in the crime-ridden neighborhood of Southeast Washington, DC, in the summer of 2014. It was four thirty a.m. and the PCP dealer, who had more than a decade of drug arrests and gun convictions, was only minutes away from becoming involved in a kidnapping and sexual assault.

A blue Toyota swerved into a nearby alley and came to a halt. This was a common spot for PCP sales. The drug dealer approached the car. Muffled sounds of a woman’s screams radiated from the vehicle. “Help me! Help me! He’s raping me.”

The drug dealer peered through the window in the dark and saw a man on top of a woman viciously attempting to rape her. Instantly he yanked open the car door, drew his gun, and pointed it at the assailant. “Get the fuck out!” he commanded.

Lateef Sharperson jumped out of his car (and nearly his skin) and fled, running with his pants dangling around his knees. The PCP dealer ordered the woman to slide over and he got into the vehicle beside her and started it up. He drove the terrified woman home to her mother in the assailant’s car and waited for the police to arrive. Sharperson was soon apprehended by police and convicted of kidnapping and first-degree sexual assault of the nineteen-year-old Trinity Washington University student. The drug dealer, who was due to appear in court himself on charges of selling PCP, suddenly became a Good Samaritan.

“I got nieces, a little sister. I got a mother. That ain’t cool,” the drug dealer testified before the jury of eight women and four men.

“A Good Samaritan doesn’t mean Boy Scout,” Assistant US Attorney Kenya Davis told the jury, in an effort to prepare them for the witness’s lawless background. In hope that the men and women would accept the testimony of a criminal, Kelly Higashi, head of the sex offense and domestic violence unit of the US Attorney’s Office, said, “He happened to be the one who rescued the woman who was being raped and who thought she was going to be killed.”

The young woman calls the nameless man “my angel.” Cooperating with police is dangerous in the drug dealer’s world, so the newspapers have kept his identity secret.

Before police arrived at the mother’s home, the drug-dealing Good Samaritan stashed his gun, he admitted to the jury. Sharperson’s attorney, Leonard Long Jr., latched onto that stashed weapon. Confronting the man on the witness stand, he asked why, if he was a Good Samaritan, did he not admit to police that night that he had a gun?

“I’m not that much on the good side yet,” the man in dreadlocks responded from the stand, setting the female jurors giggling.

Sharperson was sentenced to thirteen years in prison for abduction and sexual assault on the basis of testimony from the only witness to the attack: the Good Samaritan drug dealer.

The Organization trigger is the spark of immediate rage and violence and a peculiarly human trait that binds us into a cooperative society. While the triggers of rage and violence in men are the cause of much abuse against women, countless women have been protected or rescued from sexual assault by another man who, on an instantaneous impulse, snapped to action and risked his own life to engage in a violent battle with an individual threatening or physically harming the woman. “I got nieces. . . . That ain’t cool.”

This same snap reflex of a man coming to the aid of another person is seen in response to all the other LIFEMORTS triggers. “I do not expect to stimulate or create heroism by this fund,” Andrew Carnegie said when he established the Carnegie Hero Fund in 1904, which gives cash awards to ordinary people who save the lives of others. “That heroic action is impulsive.” Since 1904, 80,000 cases of extreme heroism have been recognized by the fund. Nine out of ten of the awards for heroism have been given to men. This is the same gender difference seen in statistics of violent crime. Ninety percent of violent criminals in prison are men, but men, in far greater numbers than women, will also instantly risk their life for a woman, child, or stranger in danger. Men do this reflexively despite the highest stakes. Nearly one in four Carnegie Hero medals is bestowed on a dead man. In each case, a man instantly surrendered his life for someone else.

On Saturday, April 26, 1986, the Chernobyl nuclear power plant sixty-five miles north of Kiev in Ukraine overheated and exploded, exposing the hot nuclear core to the outside world. Fires raged for three days, sending almost fifty tons of highly reactive fallout into the atmosphere. Once considered the breadbasket of Europe, the land surrounding the plant was poisoned by the radioactive fallout, which will continue to poison the area for 25,000 years. Some 336,000 people in 434 towns and villages in Belarus were evacuated from their homes and relocated outside the contaminated zone. As devastating as the Chernobyl disaster was, it could have been much worse.

Ten days after the explosion, an impending disaster was developing that would cause immeasurably greater devastation than the initial explosive meltdown. Water that firefighters had poured on the burning power plant for days had collected into a highly contaminated pool beneath the reactor core. The reactor core itself had melted down into a searing, intensely reactive lava oozing its way unstoppably through the reactor floor. The instant this radioactive ooze broke through and reached the water below, it would set off a massive thermal explosion that would send a deadly plume of radioactive steam across most of Europe.

Three men—Valeri Bezpalov, Alexei Ananenko, and Boris Baranov—volunteered to dive into the radioactive pool and swim using scuba gear to find the safety valves to drain the water away. Boris’s lamp failed shortly after submerging, but the three divers groped through the darkness until they found the safety valves, opened them, and drained the pool to avert the disaster. The molten lava did soon burn through the reactor floor, but by then the water was gone.

The action of these three men saved the lives of hundreds of thousands of people throughout Europe, but all three men died after two weeks of suffering with lethal radiation sickness. There are men who will risk death to save another person, but in this case there was no risk, only absolute certainty that each man would die in the act of saving others. Ananenko was an engineer who knew where the safety valves were located. Bezpalov was a soldier and engineer at the plant. Baranov was an “ordinary” worker at the plant who offered to hold the lamp while the other two men turned the safety valves. Reactor number 4 is now covered by a concrete sarcophagus, and in the distance, amid radiation levels still five times above normal, stands a memorial to these three lost workers of Chernobyl.

So it is important in discussing sex and violence not to lose perspective, as illustrated by the case of Johnny McGirr. The thirty-three-year-old firefighter was seated next to two young boys on a Virgin Australia flight in 2012 when a female flight attendant ordered him to trade seats with a woman. “You can’t sit next to two unaccompanied minors,” she said. Appealing to a female passenger, she demanded, “Can you please sit in this seat, because he is not allowed to sit next to minors.”

Johnny McGirr is not a pedophile. But four airlines—British Airways, Qantas, Air New Zealand, and Virgin Australia—prohibit adult male passengers from sitting next to unaccompanied children out of “fear of sexual assaults.” McGirr and many men like him who suffer similar discrimination on airlines with this policy feel deeply humiliated by being pegged as a criminal sexual predator for no reason other than being a male.

This discrimination against all men, because some men commit sexual crimes, highlights an important point. In examining the broad scope of human behavior on the neuroscience of gender and aggression, and the predominance of males involved in violent crime, it is vital to remember that the vast majority of men are not violent. They are not aggressive or abusers of women in any way. All members of society, men and women, with the very few exceptions of a criminal minority, are appalled by the attacks on women in Tahrir Square and by other crimes against women. These acts of animal brutality are repugnant and intolerable.

On the contrary, the neurocircuits of threat detection and sudden aggression, and the complementary differences in brain function in men and women, are what bind humans together into peaceful and cooperative groups. Countries, tribes, coworkers, families, and couples are all united by the neurocircuitry at the core of the human brain that exists for mutual protection. The reflexive concern for others, at a neuroscience level, derives from this brain circuitry in our hypothalamus.

It is the strong bond between man and woman that forms, in the biological sense, the foundation for all levels of social organization built upon it, from family to country. Males prevent violent crime. Interpol crime data show that in countries with fewer males in the population, murders, rapes, assaults, and other violent crimes increase. This may seem counterintuitive, but this fact should not be ignored. The exceptional cases of male criminal violence should not distract from the obvious: the biological role of males as protectors. This is why, after all, nature has given men bigger muscles—to provide for and protect their loved ones.

The Ties That Don’t Snap

To fall in love. Of all the verbs that could be applied, “fall” is the one we always use. We “make” friends, “get” into situations, “enter” into an agreement, “undertake” a challenge, “have” fun, but in love—we fall.

This essential aspect of the human emotion called falling in love transcends the English language. In French it is tomber amoureux; in Spanish, caer enamorado; in Russian it is vljubit’sja, and in the Thai language the expression translates into “fall into a hole or trap.”

Of all the verbs that we might have used, we say “fall” because love is a sudden unconscious brain process that operates beyond our control. We are powerless to initiate it willfully or to control it once we have fallen in love. The sudden kiss between man and woman is the stereotype plot point of romantic movies. Falling in love is indeed a snapping behavior. Sometimes love is sparked by nothing more than a silent locking of eyes between two people in a crowd. It is the same unconscious brain process and mental telepathy that Secret Service Agent Scott Moyer described, albeit in the opposite context of identifying a potential foe. When love strikes, you know it. It overpowers and consumes us.

We have examined the nine LIFEMORTS triggers of rage and the unconscious, automated brain circuits that generate sudden snap reactions to danger, and in this chapter we have seen how the Mate trigger can be the source of violence between the sexes and of violence within the sexes in competition for mates. But the powerful biological attraction between the sexes, and the compassion that the neurocircuitry of love generates, is a potent antidote to violence between the sexes, between individuals of the same sex, and among groups of people.

As with any human emotion, love can be examined and understood as a brain function that drives behavior. As with all emotions, love is the result of unconscious brain circuits, and the neurochemicals involved in this neurocircuitry of love are an important component of the LIFEMORTS system of defensive triggers. The neurocircuit of love energizes the Mate and Family triggers, which is what makes these two circuits of rage such powerful motivators of vigorous or even violent reaction to protect our children or our mates, or to evoke ruthless behavior in competition for mates. Love also fortifies the Environment, Organization, and Tribe circuits of snapping in rage by compelling us to provide for and protect our family and children and the social structures that support them. Remarkably, the same neurocircuit that was designed by evolution to bring males and females together to generate new life and to provide the necessary prolonged care for offspring by forming intense emotional bonds between mother and child, man and wife, father and family, also resulted in the emotions of compassion and altruism that bind humans into larger groups and societies.

Love is a singular and powerful emotion combining feelings of deep affection, delight, pleasure, and cherishing another person. All of the emotional components that form the core sensation of love are the result of specific neurotransmitters operating in specific brain circuits. The neurotransmitters serotonin and dopamine generate the sensation of pleasure, reward, excitement, and addiction. The neurohormone oxytocin generates the powerful feeling of attachment to another human being rooted at a deeper level in the mind than conscious reasoning, and with a grip on behavior that is more powerful than any other, including our self-interest if our loved one is in peril. This emotional response is called heroism or altruism when applied to self-sacrifice for another human being.

One of the most remarkable aspects of the human brain is that this bodily organ develops after birth, and it is not fully formed for nearly two decades spanning from infancy through childhood and adolescence. This prolonged postnatal development of the human brain requires that human offspring must be cared for, fed, taught, and protected for the incredible period of nearly twenty years. This requires strong pair bonding between man and woman, family, and a supportive social structure to care for and teach children. None of this would be possible without the powerful brain circuits of attachment that bind men and women together as lifelong partners. This circuitry of love anchors a mother’s behaviors to the care of her infants and children, with compassion, care, and self-sacrifice, and it motivates the father’s behavior toward providing for and protecting his family. (Here we are tracing the biological roots of the human brain and behavior. The modern world is complex and different from the environment of our ancestors in the human line. The modern world embraces other types of relationships and gender roles, but these roots of our past anchor our brain and behavior in all the variation of relationships that we enjoy today.)

The neurocircuitry of love that binds family and society, when applied to a higher spiritual power, is the same circuit that sustains religion. Love, compassion, altruism, and care for others are universal to all religious and spiritual beliefs. Objects of spiritual worship uncovered with bones are irrefutable archeological evidence that the bone fragments that may have lain buried for thousands of years are human. The paucity of artifacts of worship and ritualistic burial practices of Neanderthals is convincing evidence that these forerunners of Homo sapiens lacked something that is essentially human. This brain circuit of Homo sapiens caused a biological revolution that brought members of our species together into families, tribes, cooperative groups, and complex societies—all of it, fundamentally, to bring forth the next generation. This cooperative bonding enabled division of labor, specialization of individual expertise, and the development of technology. Spiritualism and religion have always had a profound role in guiding human interactions and in controlling human behavior, notably moderating behaviors that stem from misfires of the LIFEMORTS triggers. All of these complex social structures and interactions of human beings were predicated on the need to care for human offspring for the two decades it takes for the brain of Homo sapiens to develop to adulthood, and this all depends on the neurocircuit that generates deep emotional attachment between the sexes and their offspring, which we call love.

Neuroscientist James Swain and his colleagues conclude that interpersonal relationships constitute the foundation upon which human society is based, and that a specific neurobiological circuit and the secretion of oxytocin are responsible for this caregiving system.

Pair bonding, parent-infant interactions, compassion, and altruistic behavior toward others derive from a neural circuit that extends from the medial preoptic area of the hypothalamus and the ventral part of the bed nucleus of the stria terminalis, and the lateral septum. Much of the cortical-to-hypothalamic circuitry involved has already been discussed in the context of snapping, and it includes the amygdala (alarm), striatum/nucleus accumbens (motivation and reward), and cingulate cortex (decision-making). These same brain structures keep appearing and reappearing in this book not because the brain is so simplistic that there are only a few critical components to bother naming but because the snapping response in the diverse contexts being examined here engages these core brain functions. The inferior frontal gyrus, orbitofrontal cortex, insula, periaqueductal gray, and dorsomedial prefrontal cortex, which have already been described earlier in this book, regulate complex social-cognitive functions that are selectively engaged when the maternal brain responds to infant distress, whether it is hearing a baby’s cries or seeing a baby’s picture.

Empathy can be seen by brain-imaging studies on mothers while they observe and imitate facial expressions of their own child. Mothers respond to emotional expressions of their own child with activation of the insula and other cortical regions involved in imitation (mirror neuron system), in addition to the amygdala. Experience influences how these circuits develop. Mothers who report higher maternal care during their own childhood have more gray matter in cortical regions involved in maternal empathy and they have higher levels of activation in these brain regions in response to hearing their own infant’s cries compared with those of other infants.

The neurohormone oxytocin is critical in pair bonding and in parenting. Women administered oxytocin nasally show increased neural responses in the insula and other cortical regions in response to the cries of an unrelated baby. Oxytocin administration also decreases neural responses in the right amygdala. Heightened activity in the right amygdala is linked to anxiety and aversion; thus, reduced activity under the influence of oxytocin promotes positive motivations and caregiving responses—even nasty ones like changing a dirty diaper, for example. The levels of oxytocin are higher in women who give birth vaginally compared with those who had their children by cesarean delivery. Mothers who had vaginal deliveries for their children also show greater brain responses in the insula, striatum, and cingulate cortex in response to hearing baby cries. Regardless of the type of delivery, mothers show higher oxytocin levels during breastfeeding. It has been shown that mothers who formula feed have weaker response to their own infant’s cries in the insula, striatum, amygdala, and superior frontal gyrus. As will be discussed, these same circuits of empathy that are the basis for maternal-infant bonding are activated in non-caregiving situations that involve interactions among other people in society.

The neurocircuitry of love between man and woman is also engaged in spiritual belief, with very similar consequences promoting peaceful coexistence among people. Religious people highly activate a pathway from the inferolateral to dorsomedial prefrontal cortex when they contemplate the actions of supernatural and spiritual beings and agents in their life. Engaging these pathways associated with spiritual belief also regulates fear and pain circuits, and circuits responsible for theory of mind.

Theory of mind is the ability to perceive the emotions, desires, and intentions of other people—that is, to attribute specific mental states to other individuals, such as their beliefs, intents, desires, knowledge, honesty, and so on, often on the basis of complex subtle cues, and to do so very rapidly. In a word, theory of mind is empathy: the ability to put yourself in someone else’s shoes. This ability is highly developed in human beings, and it is essential to our survival as a species because strict social structure is crucial for survival of all humans. These circuits are the neurobiological basis for altruism; that is, self-sacrifice for the benefit of someone else. Religious or spiritual belief engages these brain circuits, involving the medial prefrontal cortex (mPFC), precuneus, and connections between the amygdala and prefrontal cortex. These are all brain regions and circuits that have been encountered earlier in this book in the context of fear and threat detection. Dysfunction in these circuits is associated with mental illnesses, autism, schizophrenia, ADHD, alcoholism, and other antisocial traits.

Structural differences in some brain regions are associated with religiosity; for example, the hippocampus, critical for declarative memory, is smaller in people reporting life-changing religious experiences and in born-again Protestants, but a decrease in hippocampal size is also associated with other factors, such as depression, that could interact with religious factors. The size of the orbitofrontal cortex (OFC) is linked with religious or spiritual activity. In measuring the size of the left OFC over a period of two to eight years, researchers observed less atrophy in participants who reported life-changing religious or spiritual experiences during the course of the study and in Protestant subjects who reported being born-again while entering the study.

Studies on Tibetan Buddhists show that meditation activates the precuneus network, enhancing the awareness of perceptual and cognitive states that lie beneath the awareness of conceptual thought. During silent mantra meditation, the hippocampus and prefrontal cortex become activated, but there is no activation of the cingulate cortex. This suggests a role for meditation in memory consolidation. Expert meditators control cognitive engagement in the conscious processing of sensory-related thought and emotion by strong self-regulation of the fronto-parietal and insular areas of the cortex in the left hemisphere during the meditative state. The anterior cingulate and dorsolateral prefrontal cortex play antagonistic roles in the executive control of attention, which is consistent with meditation requiring both “mind wandering” and focused attention to achieve the meditative state.

These circuits of spiritual belief affect interpersonal actions through empathy and theory of mind networks, but they also regulate internal states, including fear, pain, and stress. Stress has powerful lifesaving benefits to the brain and body, but chronic stress has adverse effects on health. Hyperactive amygdala function is often observed during stress conditions. In an MRI study of people undergoing mindfulness-based stress reduction intervention over an eight-week period, the reduction in perceived stress level was correlated with the decrease in right basolateral amygdala gray matter volume. Using fMRI to compare brain activity in practicing Catholics and atheists during painful stimulation, researchers found that analgesia (loss of pain sensation) is triggered by an image with religious content in believers, but not in the nonbelievers. Activation of these networks of religiosity enabled believers to detach themselves from the experience of pain by engaging the right ventral lateral prefrontal cortex. This indicates that religious belief enables individuals to engage pain-regulating brain processes. Brain imaging in Carmelite nuns, for example, while they were subjectively in states of union with God, showed widespread activation throughout many brain regions, but many of the regions involved in regulating fear, pain, and social interactions—including the orbitofrontal cortex, anterior cingulate cortex, and left brain stem—were engaged.

The power of this spirituality-induced analgesia is striking when one reads the horrifying accounts of religious martyrs burned at the stake—people who often endured the unimaginable pain and torture with supernatural resistance to the pain and horror—or when one sees monks in protest set themselves aflame with gasoline and remain sitting peacefully in the lotus position inside the flames as they burn to death.

Recall Todd Beamer on the hijacked flight UA 93 reciting the Lord’s Prayer together with the 911 operator before announcing, “Let’s roll.”

This analysis of the neuroanatomical and physiological correlates of religious belief should not be misconstrued as challenging religious faith. In talking with Terrence Reynolds, professor and chairman of the Department of Theology at Georgetown University, about the intersection, and often the conflict, between science and religion, he said, “Religious believers ought not be in any way unnerved by the findings of science. At the same time, one has to be careful not to engage in reductionist thinking about religion.

“Religion tends to focus on questions of meaning and value, which may not be available through analytical verification processes. If one assumes that all rationality is tied to what we know directly through the five senses, that limits our understanding of ‘meaning’ questions. . . . By definition God is a being that transcends the senses.”

Spiritual belief is a uniquely human capability. That human beings have the capacity for religious faith when animals do not means that there is something unique about the human brain that provides this ability. These neurocircuits enabling humans to have religious faith are what we are tracing here.

The neural circuitry of empathy and understanding brings people together into cooperative groups. The self-awareness these circuits convey to human beings instills a sense of awe and wonder upon the realization of the transience of an individual life in a vast and infinitely mysterious universe.

The neurocircuitry of religion, spiritualism, empathy, and theory of mind is included here in a chapter on sex and violence because it derives from the bond between men and women for sex and nonviolence, but it expands into a much larger context. Religion and the neurocircuitry engaged in spiritualism bind people into peaceful, cooperative groups and control individual and group behavior for the peace and order of society.

For centuries and throughout all cultures, religion has been one of the strongest mechanisms of self-control and social organization. “Indeed, there is a case for arguing that Homo sapiens is also Homo religious,” former Roman Catholic nun Karen Armstrong says in her book, A History of God. “Men and women started to worship gods as soon as they became recognizably human; they created religions at the same time as they created works of art.”

As our understanding of nature and the human body advances, religion and spiritualism are increasingly being supplanted by science. “Indeed, our current secularism is an entirely new experiment, unprecedented in human history. We have yet to see how it will work,” Armstrong observes.

Conversely, history and current events show vividly that religion is and always has been a source of violent aggression between individuals and among groups of people. Armstrong acknowledges the enormous conflict and destruction carried out in the name of religion, and she perceives the watershed moment that mankind appears to be approaching: “Like any other human activity, religion can be abused, but it seems to have been something that we [Homo sapiens] have always done.”

Fundamentally, the neural pathways in the human brain that allow our species to have spiritual experiences and beliefs are instrumental in peaceful coexistence as well as self-control, but when these religious beliefs become perceived as dividing people into different groups, the Tribe circuit of rage and aggression can overcome the theory of mind circuitry, giving us a sense of empathy for others. The LIFEMORTS triggers reinforce one another, but they can also come into conflict.