Chapter 4

RISK FACTORS IN ADOLESCENCE

Violence increases dramatically in the second decade of life, peaking during late adolescence at 12 to 20 percent of all young people and dropping off again sharply by the early twenties. Some of these youths followed the childhood-onset trajectory, becoming violent before puberty and escalating their rate of offending during adolescence. But over half of all violent youths begin their violent behavior in mid- to late adolescence. These youths gave little indication of problem behavior in childhood and did not have poor relations with their parents.

There are numerous theories about why violence begins in adolescence, but a few themes run through most of them (Elliott & Tolan, 1999; Pepler & Slaby, 1994). Developmentally, puberty is accompanied by major physical and emotional changes that alter a young person’s relationships and patterns of interaction with others. The transition into adolescence begins the move toward independence from parents and the need to establish one’s own values, personal and sexual identity, and the skills and competencies needed to compete in adult society. Independence requires young people to renegotiate family rules and degree of supervision by parents, a process that can generate conflict and withdrawal from parents. At the same time, social networks expand, and relationships with peers and adults in new social contexts equal or exceed in importance the relationships with parents. The criteria for success and acceptance among peers and adults change.

Adapting to all of these changes in relationships, social contexts, status, and performance criteria can generate great stress, feelings of rejection, and anger at perceived or real failure. Young people may be attracted to violent behavior as a way of asserting their independence of the adult world and its rules, as a way of gaining the attention and respect of peers, as a way of compensating for limited personal competencies, or as a response to restricted opportunities for success at school or in the community. Good relationships with parents during childhood will help in a successful transition to adolescence, but they do not guarantee it.

Adolescents exposed to violence at home may experience some of the same emotions and difficulties as younger school-age children—for example, fear, guilt, anxiety, depression, and trouble concentrating in school. In addition, adolescents may feel more vulnerable to violence from peers at school or gangs in their neighborhood and hopeless about their lives and their odds of surviving to adulthood. These young people may not experience the growing feelings of competence that are important at their stage of development. Ultimately, their exposure to violence may lead them to become violent themselves. Studies have shown that adolescents exposed to violence are more likely to engage in violent acts, often as preemptive strikes in the face of a perceived threat (Fagan & Wilkinson, 1998; Loeber et al., 1998; Singer et al., 1994, 1995).

Risk Factors by Domain

Not surprisingly, different risk factors for violence assume importance in adolescence. Family factors lose predictive value relative to peer-oriented risk factors such as weak social ties to conventional peers, antisocial or delinquent friends, and membership in a gang (Table 4-1). Even involvement in general offenses, which had the largest effect size in childhood, has only a moderate effect size in adolescence.

Individual
In early adolescence, involvement in general offenses—that is, illegal but not necessarily violent acts, including felonies—becomes a moderate risk factor for violence between the ages of 15 and 18. Its predictive power lessens from childhood, largely because teenagers are somewhat more likely than children to engage in illegal behavior.

Psychological conditions, notably restlessness, difficulty concentrating, and risk taking, have small effect sizes in adolescence. Restlessness and difficulty concentrating can affect performance in school, a risk factor whose importance increases slightly in adolescence. Risk taking gains predictive power in early adolescence, particularly in combination with other factors. A reckless youth who sees violence as an acceptable means of expression, for example, is more likely to engage in violent behavior.

Aggressiveness exerts a small effect on later violence among adolescent males, as does simply being male. While aggressiveness is unusual in children between the ages of about 6 and 10, it is not terribly unusual in adolescence. Similarly, physical violence and crimes against persons in early adolescence have a small effect on the likelihood of violence at ages 15 to 18.

Antisocial attitudes and beliefs, including hostility toward police and a positive attitude toward violence, are more important predictors among adolescent boys than they are among children, but their effect sizes remain small. Antisocial behavior and low IQ continue to have small effect sizes in adolescence.

Substance use, which was a strong predictor of later violence for children, poses a small risk of later violence for adolescents. The question as to whether drug use causes young people to become violent is complex and has been widely studied (see Miczek et al., 1994 for a review), but there is little compelling pharmacological evidence linking illicit drug use and violence. In one large study, youths reported that over 80 percent of the violent incidents they initiated had not been preceded by drug use, including alcohol use (Huizinga et al., 1995). Thus, the risk may lie more in the characteristics of the social settings in which drug use and violence are likely to occur than in any effect of drugs on behavior (Parker & Auerhahn, 1998; Reiss & Roth, 1993).

The majority of violent adolescent offenders use alcohol and illicit drugs (see Chapter 3). Illicit drug use tends to begin after the onset of violence and to be associated with more frequent violent behavior and a longer criminal career (Elliott et al., 1989). This finding suggests that drug use may contribute to continued violence rather than to the onset of violence, but it is far from conclusive. Evidence shows that some violent behavior stems from robberies or other attempts to get money to support a drug habit but also that this link is relatively rare. If any substance can be said to cause youth violence, that substance is alcohol (APA, 1993; Parker & Auerhahn, 1998); however, this causal link is inconclusive because adolescent drinking is dependent to a large degree on the situation and social context in which it takes place (for reviews, see Parker & Auerhahn, 1998; Pernanen, 1991; Reiss & Roth, 1993; Roizen, 1993).

Family
Parents’ direct influence on behavior is largely eclipsed by peer influence during adolescence. Not surprisingly, therefore, most family risk factors diminish in importance, including the influence of antisocial parents and low socioeconomic status, the most powerful early risk factors. There are no large or even moderate risk factors in the family domain in adolescence.

Poor parent-child relations continue to have a small effect size, but for adolescents this category includes inadequate supervision and monitoring of young people’s activities and low parental involvement, in addition to inappropriate discipline (Elliott et al., 1985; Hawkins et al., 1998a; Patterson & Yoerger, 1997; Roitberg & Menard, 1995). Broken homes and parental abuse also exert small effects. Other adverse family conditions present a risk factor; for example, some studies have found that family conflict is a risk factor for violence among adolescent males.

Although parents can and do influence their adolescents’ behavior, they do so largely indirectly. The kind of peers chosen by young people, for example, is related to the relationship they have with their parents (Elliott et al., 1989; Hill et al., 1999; Patterson & Yoerger, 1997; Simons et al., 1994).

School
There are no large or moderate risk factors for violence in the school domain, but poor attitude toward or performance in school—particularly if it leads to academic failure—is a slightly larger risk factor in early adolescence than in childhood.

Research on school violence indicates that a culture of violence has arisen in some schools, adversely affecting not just students but teachers and administrators as well (Gottfredson et al., in press; Lorion, 1998). Students exposed to violence at school may react by staying home to avoid the threat or by taking weapons to school in order to defend themselves (Brener et al., 1999). For their part, teachers may burn out after years of dealing with discipline problems and threats of violence.

Schools located in socially disorganized neighborhoods are more likely to have a high rate of violence than schools in other neighborhoods (Laub & Lauritsen, 1998). At the same time, however, researchers emphasize that most of the violence to which young people are exposed takes place in their home neighborhood or the neighborhood surrounding the school, not in the school itself (Laub & Lauritsen, 1998). Individual schools, like individual students, do not necessarily reflect the characteristics of the surrounding neighborhood. A stable, well-administered school in a violent neighborhood may function as a safe haven for students.

Some gang activity takes place in schools, but school gangs are generally younger and less violent than street gangs, which form in neighborhoods (Laub & Lauritsen, 1998). Gangs in schools increased dramatically (by 87 percent) between 1989 and 1995 but have recently declined (see Chapter 3). The chances of becoming a victim of violence are more than two and one-half times as great in schools where gangs are reported, and these schools are disproportionately located in disadvantaged, disorganized neighborhoods (Met Life, 1993; Snyder & Sickmund, 1999).

Peer groups complicate the picture further. They operate both in neighborhoods and in schools, but the concentration of young people in schools may intensify the influence of these groups. One large study of adolescent males found that some schools have dominant peer groups that value academic achievement and disapprove of violence, while others have groups that approve of the use of violence (Felson et al., 1994). This study found that the risk of becoming involved in violence varied depending on the dominant peer culture in their school, regardless of their own views about the use of violence.

Peer Group
Peer groups are all-important in adolescence. Adolescents who have weak social ties—that is, who are not involved in conventional social activities and are unpopular at school—are at high risk of becoming violent, as are adolescents with antisocial, delinquent peers. These two types of peer relationships often go together, since adolescents who are rejected by or unpopular with conventional peers may find acceptance only in antisocial or delinquent peer groups. Social isolation—having neither conventional nor antisocial friends—is not a risk factor for violence, however (Cairns & Cairns, 1991; Elliott & Menard, 1996; Fergusson & Lynskey, 1996; Patterson & Yoerger, 1997). A third risk factor with a large effect size on violence is belonging to a gang. Gang membership increases the risk of violence above and beyond the risk posed by having delinquent peers (Thornberry, 1998). These three peer group factors appear to have independent effects, they sometimes cluster together, and they are all powerful late predictors of violence in adolescence.

Researchers who have studied what causes young people to join gangs have found that the risk factors for gang membership are virtually the same as those for violence generally (Hill et al., 1999). The notion that gangs act as surrogate families for children who do not have close ties to their own families is not borne out by recent data (Hill et al., 1999), but gangs do strengthen young people’s sense of belonging, their independence from parents, and their self-esteem. Estimates from law enforcement agencies indicate that gang members are overwhelmingly male and the great majority (almost 80 percent) are African American or Hispanic (Snyder & Sickmund, 1999). But surveys in which young people identify themselves as gang members suggest that there are substantially larger proportions of white and female gang members. In a survey of nearly 6,000 8th graders in 1995, 25 percent of white students and 38 percent of female students reported they were gang members (Esbensen & Osgood, 1997). Lacking comparisons within ethnic groups, it is difficult to tell whether ethnicity per se is a risk factor in gang membership.

Community
Increasing involvement in the community is a healthy part of adolescent development, unless the community itself poses a threat to health and safety. Social disorganization and the presence of crime and drugs in the neighborhood pose a small risk of violence when measured on an individual level, as they are in Table 4-1. As noted in the table, however, both of these risk factors have a substantially greater effect on the neighborhood level, where they measure the average rate of violent offending by youths living in the neighborhood or community.

Socially disorganized communities are characterized in part by economic and social flux, high turnover of residents, and a large proportion of disrupted or single-parent families, all of which lessen the likelihood that adults will be involved in informal networks of social control. As a result, there is generally little adult knowledge or supervision of the activities of teenagers and a high rate of crime. Moreover, in areas experiencing economic decline, there are likely to be few neighborhood businesses. In such an environment, it is hard for young people to avoid being drawn into violence. Not only are they on their own after school, they are exposed to violent adults and youth gangs, they have few part-time job opportunities, and their neighborhood is not likely to offer many after-school activities such as sports or youth groups (Bursik & Grasmick, 1993; Sampson et al., 1997; Wilson, 1987).

Social disorganization is also a risk factor for violence in rural areas. One study of rural communities found that poverty plays a less important role in predicting violence than residential instability, broken homes, and other indicators of social disorganization (Osgood & Chambers, 2000). In fact, very poor areas were not characterized by high residential instability or a large proportion of broken homes. In cities, however, the combination of poverty with instability and family disruption is predictive of violence (Bursik & Grasmick, 1993; Elliott et al., 1996).

Adolescents who are exposed to violence in their neighborhood feel vulnerable and unable to control their lives. These feelings can lead to helplessness and hopelessness. Such young people may turn to violence as a way of asserting control over their surroundings. They may arm themselves or even join a gang for protection. Studies have shown that adolescents exposed to violence are more likely to engage in violent acts, often as preemptive strikes in the face of a perceived threat (Singer et al., 1994, 1995).

Neighborhood adults who are involved in crime pose a risk because young people may emulate them. Easily available drugs add to the risk of violence. As noted earlier, drug use is associated with both a higher rate of offending and a longer criminal career (Elliott et al., 1989). More important, ready availability of drugs indicates that considerable drug trafficking is taking place in the neighborhood—and drug trafficking is dangerous for buyer and seller alike.

Summary

Violence peaks during the second decade of life. The youths who first became violent in childhood escalate their violence in adolescence, and a larger group of young people embarks on violence in adolescence. For some young people, violence represents a way of gaining the respect of peers, enhancing their sense of self-worth, or declaring their independence from adults. Violence drops off as adolescents enter adulthood and assume adult roles.

Parents’ direct influence on behavior is largely supplanted in adolescence by peer influences. Thus the most powerful peer predictors of violence in adolescence are weak social ties to conventional peers, ties to antisocial, delinquent peers, and belonging to a gang.

Unexpected Findings and Effects

This chapter does not identify a number of characteristics and conditions frequently thought of as risk factors. Furthermore, some of the risk factors that have been identified may exhibit smaller effect sizes than expected. There are two reasons for this. First, this report relies on longitudinal studies, which identify risk factors and their effect sizes on the basis of their ability to predict future behavior. Much of this research involves identifying risks for aggression, externalizing behavior, or antisocial behavior—not risks for violence. While there is considerable overlap between the risk factors for aggression and those for violence, there are some important differences, particularly with respect to effect sizes (Hann & Borek, in press). Television violence, for example, has a very large effect on aggressive behavior but only a small effect on violence. Second, some studies that have been widely cited in the media involve cross-sectional and retrospective research designs, which are inappropriate for identifying factors that predict future violence.

Conduct disorder has been linked to youth violence in numerous studies, but the cluster of symptoms used to determine this disorder includes physical aggressiveness, nonphysical aggressiveness, and antisocial attitudes and beliefs. For purposes of predicting violence, the critical question is: What components of this disorder actually confer risk? There is some evidence that physical aggression accounts for most of the predictive power of conduct disorder (Nagin & Tremblay, 1999) and has a moderate to small effect size as a predictor of violence. Antisocial attitudes and beliefs also predict violence, but with an even smaller effect size. The three components of conduct disorder generally cluster together, which accounts for their having been combined into a single risk factor in earlier studies. Other childhood disorders such as attention-deficit/hyperactivity disorder, depressive and anxiety disorders, and their symptoms do not cause violent behavior, but their presence often signals serious behavioral and emotional problems that negatively affect family, social, and academic functioning, domains of risk for violent behavior.

Race has long been considered a risk factor for the onset of violence, and it is included as a risk factor in most studies using simple bivariate predictors of violence. The question is whether race predicts violence once other known risk factors are taken into account. Studies that have accounted for the effects of other known risk factors have typically found no significant effect of race on youth violence (Elliott et al., 1989; Reiss & Roth, 1993; Roitberg & Menard, 1995). Thus, race appears to be a risk marker rather than a risk factor. Race is a proxy for other known risk factors—living in poor, single-parent families, doing poorly at school, and being exposed to neighborhood disadvantage, gangs, violence, and crime. The evidence suggests that the link between race and violence is based largely on social and political distinctions rather than biological differences.

Ethnicity has also been proposed as a risk factor, but it has not been studied extensively enough to include here. Young people from ethnic minorities may be subject to prejudice and thus to limited opportunity, and they may face unique stresses when their family culture conflicts with the dominant U.S. culture. At the same time, their ethnic culture may offer them strong support and guidance and thus function as a protective factor (APA, 1993).

Child abuse is widely considered to be a powerful risk factor for youth violence. This belief is based on a number of early studies that suffered from serious methodological problems (see Dodge et al., 1990; Garbarino & Plantz, 1986; Howing et al., 1990; and Widom, 1989 for reviews). In more sophisticated, controlled longitudinal studies, the effects are much smaller (see Table 4-1), a finding that holds for both self-report and official record studies. In addition, studies reporting on child abuse as a predictor of nonviolent delinquent behavior or less serious offenses find larger effect sizes than those cited here for violence or serious delinquency (Bolton et al., 1977; Smith & Thornberry, 1995; Widom, 1989, 1991; Zingraff et al., 1993, 1994). Neither sexual abuse nor physical abuse is a significant predictor of youth violence when considered alone (Hawkins et al., 1998c). Sexual abuse has been linked to criminal behavior in adulthood (Widom & Ames, 1994), but not to violence in adolescence.

Although the effect size of child abuse or neglect is small when a correlation measure is used (as in Table 4-1), the relative risk of violence among abused or neglected children can be substantial. Knowing that a child was abused does not help much in predicting future violence, however, since the vast majority of abused children do not become violent. For example, one longitudinal study showed that 5 percent of abused children were arrested for a violent crime by age 18, compared to 3 percent of nonabused children (Widom, 1991). The relative risk of arrest for violence is nearly twice as great in the abused group as in the nonabused group, yet the correlation for this relationship is .07, a small effect size.⁶ In other words, even though the probability of later violence is substantially higher among abused than nonabused youths in this study, the correlation is small because the majority of all youths (95 percent of abused and 97 percent of nonabused youths) did not become violent.

When the proportion of youths who become violent is greater, the relative risks appear to be lower. Thus, when subjects in the 1991 Widom study were tracked to age 30, the relative risk of violence dropped to 1.3 (Widom, 2000). In the one longitudinal self-report study to date, which had relatively high proportions of abused children reporting violence, the relative risk of violence was 1.2 (Smith & Thornberry, 1995). In both of these cases, the correlation was less than .10.

Heredity does not seem to play a strong role in violence (see Cary, 1994 for a review). While there is some evidence supporting a genetic effect, the proposed mechanisms are very complex and nonspecific (Turbin, 2000). Neurotransmitters such as dopamine, serotonin, and GABA may play a role in aggression, but so far their mechanisms of action are unclear and there is insufficient evidence to consider them predictors of violence. In general, there are no known neurobiological patterns that are precise and specific enough to be considered reliable risk factors for violent behavior (Reiss & Roth, 1993).

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