PREDICTING SERIOUS DELINQUENCY
Over the years, a number of studies have examined risk markers for or predictors of serious delinquency, chronic offending, and violent delinquency. Several excellent summaries of that literature exist (Hawkins et al., 1998; Lipsey and Derzon, 1998; Biglan et al., 2004; Farrington and Welsh, 2007). Lipsey and Derzon (1998, p. 88), using meta-analytic techniques, identified 793 effect sizes from 66 reports of 34 independent studies, and Hawkins and colleagues (1998) identified 39 studies and provided a substantive summary of the identified risk markers. Summarizing the rather voluminous findings from these reviews in a short space is a difficult task. For an overview, see Table 6-1.
This table shows the largest effect sizes for particular risk markers at different ages. As the table shows, the identified risk markers cut across a number of developmental domains, including prior offending and aggression, as well as peer, family, and school factors. Hawkins and colleagues (1998) also found significant risk markers in all of the developmental domains they examined: individual, family, school, peer, and community. To illustrate their findings, we summarize risk markers from the area of the family: “Within the family, living with a criminal parent or parents, harsh discipline, physical abuse and neglect, poor family management practices, low levels of parent involvement with the child, high levels of family conflict, parental attitudes favorable to violence, and separation from family have all been linked to later violence” (Hawkins et al., 1998, p. 146). We can draw several important conclusions from the results presented in these and other reviews.
First, there is no single risk marker that is very strongly associated with serious delinquency. As is true of other problem behaviors, there are multiple risk markers drawn from multiple domains, each of which, alone, is only modestly related to these outcomes. In other words, there is no single solution on which to focus efforts to prevent serious delinquency. This behavior pattern appears to come about from the accumulation of risk across many domains (Hawkins et al., 1998; Lipsey and Derzon, 1998; Biglan et al., 2004; Farrington and Welsh, 2007; Howell, 2009).
Second, risk for serious delinquency is generated across multiple developmental stages from infancy through childhood and into adolescence, with risk markers at each stage making contributions to the origins of serious delinquency. Although early risk markers have a role to play, they are clearly not determinative of these outcomes. However, early risk markers are predictive of the development of new risk markers for delinquency at subsequent ages. For example, risk indicators during early childhood, such as increased aggression and hyperactivity, are predictive of peer rejection and either peer isolation or attachment to delinquent peers; both of these