Chapter 4

RISK FACTORS IN CHILDHOOD

The first decade of life encompasses a vast period of human development. Infants form attachments to parents or other loving adults and begin to become aware of themselves as separate beings. As toddlers, they begin to talk, to assert themselves, to explore the world around them, and to extend their emotional and social bonds to people other than their parents.

The start of school is a milestone in children’s continuing social and intellectual development. Other children become more important in their lives, though still not as important as family members. They begin to empathize with others and hone their sense of right and wrong. As they progress through elementary school, children gain valuable reasoning and problem-solving skills as well as social skills.

Exposure to or involvement in violence can disrupt normal development of both children and adolescents, with profound effects on their mental, physical, and emotional health.⁴ In addition, exposure to violence affects children and adolescents differently at different stages of development (Marans & Adelman, 1997).

Young children exposed to violence may have nightmares or be afraid to go to sleep, fear being left alone, or regress to earlier behavior, such as baby talk or bed-wetting. They may exhibit excessive irritability or excitability. Violence in the family, especially, may inhibit young children’s ability to form trusting relationships and develop independence.

Elementary school children who live in violent neighborhoods may also experience sleep disturbances and be less likely to explore their environment. In addition, they can become frightened, anxious, depressed, and aggressive. They may have trouble concentrating in school. Because they understand that violence is intentional, they may worry about what they could have done to prevent or stop it (Osofsky, 1999).

Violence also affects parents. Adults living in violent households or neighborhoods may not be able to keep their children safe or to protect them from harmful influences. Some parents living in unsafe neighborhoods do not let their children play outside. While this solution may safeguard children temporarily, it can also impede healthy development. Parents in these situations understandably feel helpless and hopeless. Those who have been traumatized by violence themselves may, like their children, become anxious, withdrawn, or depressed. Under such circumstances, parents cannot respond spontaneously and joyously to their children, making it difficult for children to develop strong, secure attachments to their parents. Forming a bond with a loving, responsive parent or other adult caregiver is an essential factor in healthy development (Furstenberg et al., 1999; Osofsky, 1999; Patterson & Yoerger, 1997). Children and families exposed to or involved in violence may want to seek professional advice in addressing their mental, physical, and emotional health concerns.

Risk Factors by Domain

A few risk factors for youth violence occur before birth. Others come into play as the child develops in response to his or her family and surroundings. Thus, most of the risk factors that exert an effect before puberty are found in the individual and family domains rather than in the larger world, a situation that changes dramatically in adolescence. Childhood risk factors are listed by domain in Box 4-1; effect sizes are listed in Table 4-1.

Individual
The most powerful early risk factors for violence at age 15 to 18 are involvement in general offenses and substance use before age 12. General offenses include serious, but not necessarily violent acts, such as burglary, grand theft, extortion, and conviction for a felony. Children engaging in such crimes often come to the attention of the police and juvenile justice system. Numerous studies have documented the overlap between serious nonviolent and violent offenses in adolescence, so early involvement in serious offenses carries a substantial risk for violence later.

Experimentation with drugs, alcohol, tobacco, or some combination of these substances is not particularly unusual by age 18, but use of these substances by children under the age of 12 is. Not only are these substances harmful to health, they are illegal. Thus, use of these substances signals antisocial attitudes and early involvement in a delinquent lifestyle that often comes to include violent behavior in adolescence (Fagan, 1993).

Two moderate risk factors emerge in childhood, being male and aggression. Boys (and young men) are far more likely than girls to be violent (see Chapter 2), yet some researchers have suggested that sex is a risk marker rather than a risk factor (Earls, 1994; Hawkins et al., 1998a; Kraemer et al., 1997). A risk marker is a characteristic or condition that is associated with known risk factors but exerts no causal influence of its own (Earls, 1994; Patterson & Yoerger, 1997).⁵ For example, many more boys than girls are hyperactive, a risk factor with a small effect size, so some of the predictive power of being male may actually be the influence of hyperactivity. Moreover, boys have traditionally been exposed to more violence than girls, and socially approved male role models are more aggressive, suggesting that social learning plays a role in this risk factor. However, research indicates that being male confers risk even after accounting for other known risk factors. This suggests that being male is a risk factor rather than a risk marker, perhaps with some biological or biological-environmental interaction as the causal mechanism.

Many studies have found aggression—characterized as aggressive and disruptive behavior, verbal aggression, and aggression toward objects—to be a moderate risk factor among boys, although there is some evidence that physical aggressiveness is actually responsible for most of the observed effect (Nagin & Tremblay, 1999). Additional research is needed to sort out the unique influence of each of these types of aggression.

The remaining individual risk factors have relatively small effect sizes. Various psychological conditions, such as hyperactivity, impulsiveness, daring, and short attention span, pose a small risk for violence. A consistent individual predictor is hyperactivity/low attention, the central components of attention-deficit/hyperactivity disorder (ADHD), a cognitive disorder that may be genetically influenced in some way (Hawkins et al., 1998a). ADHD is characterized by restlessness, excessive activity, and difficulty paying attention, traits that may also contribute to low academic performance, a risk factor in school. Hyperactivity is often found in combination with physical aggression, another risk factor. Some researchers question the independent effect of hyperactivity on later violence, suggesting that the effect is actually physical aggression (and perhaps low academic performance) that was not controlled for in earlier studies of hyperactivity (Nagin & Tremblay, 1999). There is little agreement about the mechanism linking hyperactivity to violence.

The effects of children’s exposure to television and film violence have been studied extensively in regard to aggression, but there is relatively little research regarding the effects on more serious forms of violent behavior (for an extended discussion, see Appendix 4–B). Experimental studies have found that exposure to media violence has a small average effect size (.13) on serious forms of violence (Paik & Comstock, 1994); the average effect size in cross-sectional survey studies was very small (.06). Two frequently cited longitudinal studies have examined the effects that exposure to television violence in childhood produces on violent behavior during adolescence or early adulthood. One, in which participants reported having punched, beaten, or choked someone as young adults, found a significant predictive effect for women (.22) but no significant effect for men (Huesmann et al., submitted). The other study, in which teenage males reported being involved in a knife fight, car theft, mugging, gang fight, or similar delinquent behavior, found a statistically significant predictive effect in only one of nine tests (Milavsky et al., 1982). Exposure to violence appears to have a weak predictive effect on relatively immediate violence in experimental studies, but there is little consistent evidence to date for a long-term predictive effect.

Little research has been done on violence in other media—video games, music videos, and the Internet. A recent meta-analysis by Anderson and Bushman (in press) reports that video game violence has a small average effect size (.19) on physical aggression in experimental and cross-sectional studies. Theoretically, the influence of these interactive media might well be greater than that of television and films, which present a passive form of exposure, but there are no studies to date of the effects of exposure to these types of media violence and violent behavior.

Problem behavior, another risk factor with a small effect size, refers to relatively minor problem behaviors such as stealing, truancy, disobedience, and temper tantrums. While not serious in themselves, antisocial behaviors may set the stage for more serious nonviolent or violent behavior later.

The medical or physical risk factor includes a number of conditions that as a group are somewhat predictive of violence. Prenatal and early postnatal complications, a more specific set of medical conditions, have been found to have inconsistent effects across a number of studies (Hawkins et al., 1998c). These complications encompass a broad group of genetic conditions or physical injuries to the brain and nervous system that interfere with normal development, including low birth weight, oxygen deprivation, and exposure to toxins such as lead, alcohol, or drugs (Hawkins et al., 1998b). Low resting heart rate, a condition that has been studied primarily in boys, is associated with fearlessness or stimulation seeking, both characteristics that may predispose them to aggression and violence (Raine et al., 1997; Hawkins et al., 1998c), but there is not enough evidence to establish this condition as a risk factor for violence. Some studies have even questioned its effects on aggression (Van Hulle et al., 2000; Wadsworth, 1976; Kindlon et al., 1995). There is also no evidence that internalizing disorders—nervousness and withdrawal, anxiety, and worrying—are related to later violence (Hawkins et al., 1998c).

Low IQ, or low intelligence, includes learning problems and poor language ability. This risk factor has a small effect size and is often accompanied by other risk factors with small effect sizes, such as hyperactivity/low attention and poor performance in school.

Antisocial beliefs and attitudes, including dishonesty, rule-breaking, hostility to police, and a generally favorable attitude toward violence, usually constitute a risk factor in adolescence, not childhood (Hawkins et al., 1998c). Only dishonesty in childhood is predictive of later violence or delinquency, and its effect is small.

Family
There are no known strong risk factors for youth violence in the family domain, but low socioeconomic status/poverty and having antisocial parents are moderate factors. Socioeconomic status generally refers to parents’ education and occupation as well as their income. Poorly educated parents may be unable to help their children with schoolwork, for example, and children living in poor neighborhoods generally have less access to recreational and cultural opportunities. In addition, many poor families live in violent neighborhoods, and exposure to violence can adversely affect both parents and children, as described above. Limited social and economic resources contribute to parental stress, child abuse and neglect, damaged parent-child relations, and family breakup—all risk factors with small effects in childhood.

Studies suggest that antisocial parents—that is, violent, criminal parents—represent an environmental rather than a genetic risk factor (Moffitt, 1987). In other words, children learn violent behavior by observing their parents rather than by inheriting a propensity for violence. In fact, attachment to parents, a possible protective factor, can have the opposite effect if the parents are violent (Hawkins et al., 1998c).

Among the early risk factors with small effect sizes on youth violence is poor parent-child relations. One specific risk factor in this class—harsh, lax, or inconsistent discipline—is also somewhat predictive of later violence (Hawkins et al., 1998c). Children need reasonable, consistent discipline to establish the boundaries of acceptable and unacceptable behavior. Children who are treated harshly may view rough treatment as acceptable, those who are given no guidance may engage in whatever behavior gets them what they want, and children who receive mixed signals are completely at sea regarding appropriate behavior. Other family conditions, such as high stress, large size, and marital discord, also exert a small effect on later violence.

Another childhood predictor with a small effect size is broken homes, a category that includes divorced, separated, or never-married parents and a child’s separation from parents before age 16. Separation from parents also operates as a distinct risk factor, again with a small effect size.

Abusive parenting in general and neglect in particular are predictors of later violence, but they have very small effect sizes. Neglect operates as a distinct risk factor, possibly because neglected children are less likely to be supervised or taught appropriate behavior. This is not to imply that child abuse and neglect do not cause serious problems in adolescence: Indeed, they have large effects on mental health problems, substance abuse, and poor school performance (Belsky & Vondra, 1987; Cicchetti & Toth, 1995; Dembo et al., 1992; Esbensen & Huizinga, 1991; Silverman et al., 1996; Smith & Thornberry, 1995). This finding is discussed in more detail below, in the section on unexpected findings and effects.

School
The only early risk factor in the school domain is poor attitude toward and performance in school, and its effects are small. Numerous individual and family factors may contribute to poor performance, making it a fairly broad measure. For example, a child who is physically aggressive and is rejected by peers or who has difficulty concentrating or sitting still in class may understandably have difficulty performing academic tasks. Children who have been exposed to violence, as noted earlier, may also have trouble concentrating in school.

Peer Group
Young children do not socialize extensively with other children and are not strongly influenced by peers. Peers become more important as children progress through elementary school, although school-age children still look primarily to parents for cues on how to behave. Nonetheless, weak social ties to conventional peers and associating with antisocial peers both exert small effects in childhood.

Children with weak social ties are those who attend few social activities and have low popularity with conventional peers. School-age children often reject physically aggressive children because of their inappropriate behavior (Hann & Borek, in press; Reiss & Roth, 1993). The combination of rejection and aggressiveness exacerbates behavior problems, making it more difficult for aggressive children to form positive relationships with other children. Indeed, recent research indicates that children who are both aggressive and rejected show poorer adjustment in elementary school than children who are aggressive, rejected, or neither (Hann & Borek, in press).

Being drawn to antisocial peers may introduce or reinforce antisocial attitudes and behavior in children. Indeed, aggressive children tend to seek each other out (Hann & Borek, in press).

Community
Community risk factors, such as living in socially disorganized neighborhoods or neighborhoods with high rates of crime, violence, and drugs, are not powerful individual-level predictors in childhood because these external influences have less direct impact on children than on adolescents. They may well exert indirect influences through poor parenting practices, lack of family resources, and parent criminality or antisocial behavior.

Summary

The most powerful early predictors of violence at age 15 to 18 are involvement in general offenses (serious, but not necessarily violent, criminal acts) and substance use. Moderate factors are being male, aggressiveness, low family socioeconomic status/poverty, and antisocial parents.

Footnotes