Jessie paced small, frantic paths in the bedroom, listening for what was next. She heard Charley thunder down the hall, rifle the drawer in the bathroom, and then she was outside the door again, picking the lock with a bobby pin until pop!—the knob sprang unlocked. Jessie’s heart raced as Charley threw her considerable weight against the now slightly open door. She watched the back of the chair and the doorknob give a little, and she pushed a small dresser in front of the door as well, her heart racing some more. Unable to get in, Charley moved on and Jessie’s heart slowed a little as she sank down to the floor and put her back against the dresser that was against the door. She sat and stared for a while at the electrical outlets across the room. She appreciated the way they looked back at her like little faces, wide-eyed and mouths agape with horror, the only witnesses around.
Hours later, when Jessie heard the clack of her mother’s heels just home from work, she pulled her dresser from the door and the chair out from under the knob. She marched into the kitchen and, in a flood of tears, told about the hitting and the phone and the chair and the dresser and her worries about the dog next door. Jessie’s mother listened, but perhaps because she did not have enough money for a babysitter, she could not afford to acknowledge that Jessie was being abused: “Just go straight to your room after school, honey, and lock the door until I get home,” she said. “Problem solved.”
***
Home is the most dangerous place in America and, by many accounts, the sibling relationship is the most violent within those four walls. Aggression between siblings is believed to be the most common form of family violence, with violence between siblings more prevalent than spousal abuse and child abuse combined. National statistics are difficult to come by because sibling violence is rarely reported to authorities—and when it is it tends to be legally ignored as a family problem—but extensive survey data paint a disturbing picture.
Multiple large studies estimate that about one-third of children are hit, kicked, punched, bitten, or attacked by a brother or a sister in any given year. By the time they leave home, between one-half and three-quarters of young adults will have been the victim of physical aggression by a brother or a sister at least once. Though many of these acts are isolated slugs in a crowded backseat or the occasional kick over a toy, a concerning number of assaults are serious and even recurring, and they result in cuts, bruises, broken bones, and chipped teeth. This physical abuse is often accompanied by even more frequent emotional abuse: intimidation, ridicule, belittling, and threats toward pets and possessions. Between 3 and 14 percent of young adults report having been threatened by a sibling with a gun or a knife, and some of these aggressive siblings turn their rage against their parents as well. Findings like these have led researchers to conclude that “children are the most violent persons in American families.”
Sibling violence may be pandemic but, ironically, its ubiquity only contributes to it being seen as harmless. Pervasive cultural stories reinforce the notion that fighting between siblings is, if unfortunate, likely inevitable. The myth of Romulus and Remus tells us that Rome was founded by Romulus after he killed his brother in an argument over land. In the first family of the so-called Abrahamic religions, Adam and Eve’s older son, Cain, killed their younger son, Abel, in a jealous rage. Though certainly intended as cautionary, tales like these normalize family violence, suggesting that sibling rivalry and aggression are as ancient as civilization, as old as humankind.
The line between sibling rivalry and sibling abuse is admittedly a blurry one, and like Jessie’s mother, many parents trivialize sibling violence as a normal part of childhood. “That’s what kids do,” some say, or “My brother used to hit me and I turned out all right.” Perpetrators of violence are more likely to be older siblings and male siblings, a fact that is easy to shade as “boys will be boys.” While sisters can be chronically and seriously abusive, and they may be genuinely terrifying and dangerous to a child like Jessie, girls are often not seen by adults as legitimate threats. Even brothers and sisters who are on the receiving end of aggression at the hands of siblings minimize their own experiences, preferring labels such as sibling conflict and rivalry rather than sibling violence or abuse.
Violence between siblings tends to be more frequent before adolescence but more extreme after adolescence. Aggression among young children is common and usually peaks before the teen years, as kids learn better strategies for handling frustration and as they become busy with friends and activities outside of the home. Because many warring brothers or sisters “grow out of it” and violence between young siblings may not leave permanent physical scars, parents often deny its significance. Nevertheless, aggression between young children can be frequent and can have long-lasting emotional effects; intersibling violence has been linked to subsequent school bullying, anxiety, depression, and dating and domestic violence. Violence that does continue into high school tends to be increasingly severe and injurious, as older children are bigger and stronger, and have access to more dangerous weapons.
At a time when nations are taking school bullying and violence so seriously, it is unclear why we dismiss aggression between siblings as unimportant. Children are more likely to be hit—once, and again and again—by a brother or a sister than by a peer. And unlike peers who may shift with grades and whims, the sibling relationship is for many years inescapable and, as in Jessie’s case, can make home feel like a prison. Typically our only “cradle-to-grave” bond, brothers and sisters can be among the most influential—or damaging—figures in our lives. Parents may be our template for romantic relationships, but peers are often our template for social ones. Younger siblings already watch their older siblings more closely than they watch their parents, so what happens when a sibling is dangerous to boot?
***
“The best predictor of future behavior is past behavior,” renowned psychoanalyst-turned-behaviorist Albert Ellis purportedly said. Children who grow up with stress and violence know this, and as a result they develop what are called “traumatic expectations,” or the strong belief that more bad things are coming their way. They live moment-to-moment with what psychologist Jerome Kagan termed an “anxiety of premonitions.” There is often, or even always, the free-floating feeling—the realistic fear—that something is about to go wrong. Consciously or unconsciously scanning the environment for danger, children like Jessie become keen observers of the world around. They pay exquisite attention to details and to the moods and behaviors of others and, because they cannot expect others to be there for them, they learn to watch out for themselves. They become vigilant.
In her vivid memoir, The Glass Castle, Jeannette Walls details life with an alcoholic father and a neglectful mother, a childhood that included being burned in a stove fire at age three and, not too many years later, fleeing a flophouse that was ablaze. “I lived in a world that at any moment could erupt into fire,” she writes plainly. “It was the sort of knowledge that kept you on your toes.” One part of the brain that keeps us on our toes—that keeps us vigilant—is the amygdala. The amygdala is hard at work not just during fight or flight but also in all of those moments that precede the need for fight or flight. It triggers a state of heightened arousal not only when there is clear and present danger but also in uncertain and potentially dangerous situations. In what, fittingly, is called the smoke detector principle, our amygdalae (and the defenses they trigger) err on the side of being overly sensitive and overly responsive; a false positive is preferable to a false negative. If you are Jeannette Walls, you need that fire alarm to ring out loud, and not when the whole house is on fire, but at the very first sign of smoke.
Our brains adapt to the lives we lead, and research suggests that chronic stress that repeatedly activates the amygdala creates long-lasting alterations, including heightened sensitivity to threat. These sorts of changes can be seen among soldiers who have returned from war. In one study, researchers used fMRI scans to compare activity in the amygdalae of two groups of soldiers. One group consisted of thirty-three soldiers who were deployed to Afghanistan, where their duties included combat patrols, landmine removal, and transportation across enemy territory, and where they took enemy fire and saw seriously injured soldiers and civilians. The other group consisted of twenty-six soldiers who were never