Several juvenile justice researchers have linked risk factors to delinquency (Hawkins et al., 1998; Lipsey and Derzon, 1998), and many have also noted a multiplicative effect if several risk factors are present. Herrenkohl and colleagues (2000) report that a 10-year-old exposed to six or more risk factors is 10 times as likely to commit a violent act by age 18 as a 10-year-old exposed to only one risk factor.

Similarly, the age range or developmental period during which a youth is exposed to a specific risk factor is important to individuals working to tailor prevention programs to specific factors. Youth Violence: A Report of the Surgeon General (2001 (chapter 4)) elaborates:

Violence prevention and intervention efforts hinge on identifying risk and protective factors and determining when in the course of development they emerge. To be effective, such efforts must be appropriate to a youth's stage of development. A program that is effective in childhood may be ineffective in adolescence and vice versa. Moreover, the risk and protective factors targeted by violence prevention may be different from those targeted by intervention programs which are designed to prevent the recurrence of violence.

The study of risk factors, therefore, is critical to the enhancement of prevention programs that frequently have limited staffing and funding. Identifying which risk factors may cause delinquency for particular sets of youth at specific stages of their development may help programs target their efforts in a more efficient and cost-effective manner. The table, which was adapted from a report by the Office of the Surgeon General, categorizes risk factors by age of onset of delinquency and identifies corresponding protective factors.