Violent Behavior

Epidemiology

In 2015, homicide in the United States was the 3rd leading cause of death for 10-24 yr olds, totaling 4,979 deaths, which were largely males (87%) killed by a handgun (90.1%). The 2015 homicide rate for teens ages 12-17 yr was 3.1/100,000 youth, down 65% from 8.4/100,000 youth in 1993. WHO reports that other than the United States, where the youth and young adult homicide rate was 11 per 100,000, most countries with homicide rates above 10 per 100,000 are developing nations or countries with rapid socioeconomic changes. In the United States the prevalence of behaviors that contribute to violence has not decreased since 1999; fighting, weapon carrying, and gang involvement remain prevalent among youth. Gang-related homicides among youth in 5 major U.S. cities are more likely to involve young (15-19 yr) males (80%), racial/ethnic minorities (73%), and a firearm (90%) in comparison to homicides unrelated to gang activity. In addition, gang homicides are more likely to occur in public places, in the afternoon/evening hours, and rarely are related to drug trade/use. Furthermore, the rate of homicide in youth had been declining but showed an increase in 2015 ( Fig. 139.1 ).

Adolescent reports of physical fighting have decreased from 42% in 1991 to 23% in 2015. Violence at U.S. schools remains a significant problem, however, with 7.8% of students reporting being in a physical fight on school property 1 or more times in the preceding 12 mo. The 2015 Youth Risk Behavior Surveillance System reported 16.2% of youths overall carried a weapon such as a gun, knife, or club in the last 30 days; 4.1% carried the weapon to school; and 6.0% reported being threatened or injured with a type of weapon on school property. Males are more likely than females to carry a gun or weapon and therefore may need more support and engagement at home and at school. Weapon carrying is highest among white males overall, which may begin as early as 9th grade. These violence-related behaviors at school affect the general students' perception of safety. More than 5.6% of students did not go to school on 1 or more days in the preceding 30 days because they felt it was unsafe. School-based prevention programs initiated at the elementary school level have been found to decrease violent behaviors in students. Increased surveillance of students is warranted both on and around school property to improve student safety.

Dating violence (or intimate partner violence) occurs between 2 people in a close relationship and can be physical (punching, kicking, hitting, shoving), emotional (shaming, bullying, controlling, stalking), or sexual (forcing partner to engage in a sexual act when he/she does not consent to it). Incidents of dating violence often occur during the adolescent years, with 22.4% of women and 15% of men experiencing some type of partner violence between the ages of 11 and 17 yr. The highest prevalence rates are seen in black students and older students. It may start with teasing, name calling, or shaming but often progresses electronically, as frequent calls, texting, or posting sexual pictures of a partner on social media. Risk factors for being a victim of dating violence includes those who use alcohol, believe dating violence is acceptable, have lack of parental supervision, or have a friend who is in a violent relationship. Most teens do not report the behaviors due to fear of retaliation from the partner. Teens who are victims of dating violence are more likely to experience decreased school performance, have thoughts about suicide, use drugs and alcohol, develop an eating disorder, experience depression, and are more likely to be victimized during college. School-based prevention programs that address attitudes and behaviors linked with dating violence, such as Safe Dates and Dating Matters , offer training experiences to change social norms among teens.

Etiology

WHO places youth violence in a model within the context of 3 larger types of violence: self-inflicted, interpersonal, and collective. Interpersonal violence is subdivided into violence largely between family members or partners and includes child abuse. Community violence occurs between individuals who are unrelated. Collective violence incorporates violence by people who are members of an identified group against another group of individuals with social, political, or economic motivation. The types of violence in this model have behavioral links, such that child abuse victims are more likely to experience violent and aggressive interpersonal behavior as adolescents and adults. Overlapping risk factors for the types of violence include firearm availability, alcohol use, and socioeconomic inequalities. The benefit to identifying common risk factors for the types of violence lies in the potential for intervening with prevention efforts and gaining positive outcomes for more than 1 type of violent behavior. The model further acknowledges 4 categories that explore the potential nature of violence as involving physical, sexual, or psychological force, and deprivation.

The social-ecologic model of public health focuses on both population-level and individual-level determinants of health and their respective interventions. On the individual level, there may be 2 types of antisocial youth: life course persistent and limited. Life course–limited offenders have no childhood aberrant behaviors and are more likely to commit status offenses such as vandalism, running away, and other behaviors symbolic of their struggle for autonomy from parents. Life course–persistent offenders exhibit aberrant behavior in childhood, such as problems with temperament, behavioral development, and cognition; as adolescents they participate in more victim-oriented crimes. The existence of adverse childhood events foretells future health issues and subsequent violence. This hypothesis proposes that precursors such as child abuse and neglect, a child witnessing violence, adolescent sexual and physical abuse, and adolescent exposure to violence and violent assaults predispose youths to outcomes of violent behavior, violent crime, delinquency, violent assaults, suicide, or premature death. This public health model also emphasizes the community environment and other external influences. An additional common paradigm for high-risk violence behavior poses a balance of risk and protective factors at the individual, family, and community levels.