A difficulty with the literature on risk factors is the diversity of the outcome behaviors studied. Some studies focus on behavior that meets diagnostic criteria for conduct disorder or other antisocial behavior disorders; others look at aggressive behavior, or lying, or shoplifting; still others rely on juvenile court referral or arrest as the outcome of interest. Furthermore, different risk factors and different outcomes may be more salient at some stages of child and adolescent development than at others.
Much of the literature that has examined risk factors for delinquency is based on longitudinal studies, primarily of white males. Some of the samples were specifically chosen from high-risk environments. Care must be taken in generalizing this literature to girls and minorities and to general populations. Nevertheless, over the past 20 years, much has been learned about risks for antisocial and delinquent behavior.
This chapter is not meant to be a comprehensive overview of all the literature on risk factors. Rather it focuses on factors that are most relevant to prevention efforts. (For reviews of risk factor literature, see, for example, Hawkins et al., 1998; Lipsey and Derzon, 1998; Rutter et al., 1998.) The chapter discusses risk factors for offending, beginning with risks at the individual level, including biological, psychological, behavioral, and cognitive factors. Social-level risk factors are discussed next; these include family and peer relationships. Finally, community-level risk factors, including school and neighborhood attributes, are examined. Although individual, social, and community-level factors interact, each level is discussed separately for clarity.
A large number of individual factors and characteristics has been associated with the development of juvenile delinquency. These individual factors include age, gender, complications during pregnancy and delivery, impulsivity, aggressiveness, and substance use. Some factors operate before birth (prenatal) or close to, during, and shortly after birth (perinatal); some can be identified in early childhood; and other factors may not be evident until late childhood or during adolescence. To fully appreciate the development of these individual characteristics and their relations to delinquency, one needs to study the development of the individual in interaction with the environment. In order to simplify presentation of the research, however, this section deals only with individual factors.
Studies of criminal activity by age consistently find that rates of offending begin to rise in preadolescence or early adolescence, reach a peak in