Chapter 4

CONCLUSIONS

Scientists have identified a number of personal characteristics and environmental conditions that put children and adolescents at risk of violent behavior and some that seem to protect them from the effects of risk. These risk and protective factors can be found in every area of life, they exert different effects at different stages of development, they tend to appear in clusters, and they appear to gain strength in numbers. The public health approach to youth violence involves identifying risk and protective factors, determining when in the life course they typically come into play, designing preventive programs that can be put in place at just the right time to be most effective, and making the public aware of these findings.

Many years of research have yielded valuable insights into the risk factors involved in the onset and developmental course of violence. Less work has been done on protective factors, but that situation is changing. Some basic principles have emerged from these studies:

• Risk and protective factors exist in every area of life—individual, family, school, peer group, and community. Individual characteristics interact in complex ways with a child’s or adolescent’s environment to produce violent behavior.
• Risk and protective factors vary in predictive power depending on when in the course of human development they occur. As children move from infancy to early adulthood, some risk factors will become more important and others less important. Substance use, for example, is a far more powerful risk factor at age 9 than it is at age 14.
• Risk factors do not operate in isolation—the more risk factors a child or young person is exposed to, the greater the likelihood that he or she will become violent. Risk factors can be buffered by protective factors, however. An adolescent with an intolerant attitude toward violence is unlikely to engage in violence, even if he or she is associating with delinquent peers, a major risk factor for violence at that age.
• Risk factors increase the likelihood that a young person will become violent, but they may not actually cause a young person to become violent. Scientists view them as reliable predictors or even as probable causes of youth violence. They are useful for identifying vulnerable populations that may be amenable to intervention efforts.
• Risk markers such as race or ethnicity are frequently confused with risk factors; risk markers have no causal relation to violence.
• No single risk factor or combination of factors can predict violence with unerring accuracy. Few young people exposed to a single risk factor will become involved in violent behavior; similarly, most young people exposed to multiple risks will not become violent. By the same token, protective factors cannot guarantee that a child exposed to risk will not become violent.
• Researchers have identified at least two onset trajectories for youth violence: a childhood trajectory that begins before puberty and an adolescent one that begins after puberty. Violence peaks during the second decade of life. The small group of offenders who began their violent behavior in childhood commits more violent offenses, and the larger group of adolescent offenders begins to become involved in violence.
• Early risk factors for violence in adolescence include involvement in serious (but not necessarily violent) criminal acts and substance use before puberty, being male, aggressiveness, low family socioeconomic status/poverty, and antisocial parents. All of these early risks stem from a child’s individual characteristics and interaction with his or her family. The influence of family is largely supplanted in adolescence by peer influences; thus, risk factors with the largest predictive effects in adolescence include weak social ties to conventional peers, ties to antisocial or delinquent peers, and belonging to a gang. Committing serious (but not necessarily violent) criminal offenses is also an important risk factor in adolescence. Drug selling is a risk factor, but its effect size has not been established.
• Identifying and understanding how protective factors operate is potentially as important to preventing and stopping violence as identifying and understanding risk factors. Several protective factors have been proposed, but to date only two have been found to buffer the risk of violence—an intolerant attitude toward deviance and commitment to school. Protective factors warrant more research attention.
• Violence prevention and intervention efforts hinge on identifying risk and protective factors and determining when in the course of development they emerge. More research in these areas is needed, particularly concerning why violence stops or continues in childhood and adolescence. Nonetheless, the research carried out to date provides a solid foundation for programs aimed at reducing risk factors and promoting protective ones—and thereby preventing violence, the subject of Chapter 5.