A typology of adolescent delinquency: sex differences and implications for treatment

BACKGROUND: This paper presents a test of Moffitt's theory (1990, 1993a) regarding offending trajectories as it applies to a population of adolescent offenders. This study is novel since few studies have empirically explored Moffitt's theory (1990, 1993a) with adolescent populations. METHOD: Data were collected retrospectively on 174 adolescents (101 males and 73 females), aged 13 to 18. Three groups of offenders were identified based on a two-step cluster analysis: well adjusted, internalizing and externalizing groups. RESULTS: Consistent with Moffitt's theory, a sub-sample of offenders (externalizing group) engaged in more problem behaviours than the other offending groups. Additionally, female offenders in the internalizing group evidenced more psychopathology than males in this offending group as well as females in the other offending groups. Offending rates, in terms of offending frequency and variety of criminal offences, were not distinguished between the groups. CONCLUSIONS: These results provide evidence for Moffitt's theory (1990, 1993) regarding trajectories in adolescent offending. This study also provides support for the theory developed by Silverthorn and Frick (1999) regarding female offending. This was particularly evident in the rates of psychopathology evidenced by a sub-sample of adolescent females in the internalizing group.