In 1993, Terrie Moffitt posited the theory that juvenile delinquents as a population of study are comprised of two distinctly different types of individuals: the life-course-persistent antisocial individual and the adolescence-limited antisocial individual. Moffitt's theory provides a number of insights into the nature of delinquency, as well as important implications for juvenile justice policy and procedure.In order to best understand the implications of Moffitt's theory for juvenile justice policy and practice, it is best to begin with an overview of the differences between the two types of antisocial individuals presented and the difficulties inherent in distinguishing between the two groups. In summarized form, life-course-persistent antisocial individuals are those whose behavioral problems begin in childhood, remain consistent through adolescence, and persevere through adulthood. Adolescence-limited antisocial individuals, however, go through a temporary, situationally behaviorally problematic period that generally occurs between the time of pubescent maturity and young adulthood. It is important to note that, according to Moffitt (1993), adolescent newcomers to antisocial behaviors, despite a lack of prior experience, equal their preschool-onset peers with regards to the variety and frequency of laws broken as well as the number of times referred to juvenile court. Therefore, based on the commonly used indexes of adolescent delinquency, and when viewed through cross-sectional studies by researchers, the two groups become indistinguishable.With regards to distinguishing between the two groups, especially as related to the way in which antisocial youth are seen by the juvenile justice system, it becomes imperative to obtain knowledge of an adolescent's behavior from early childhood through the current time-frame. Without such knowledge, a differential diagnosis between the two types of antisocial individuals is impossible, and successful intervention and treatment then becomes less likely depending upon the type of offender and the sanctions imposed. As an example, many adolescence-limited youths will receive sanctions that will serve to maintain their delinquent behaviors instead of providing them with opportunities to “age out” of their delinquent behavior, such as incarceration, an interrupted education, the formation of a drug habit, or teen parenthood. In addition, interventions with life-course-persistent adolescents are typically met with lackluster results due to their proclivity to turn positive opportunities into ways in which they can maintain continuity with their antisocial behavior. An example of this behavior includes turning residential treatment programs into opportunities to learn from and associate with criminal peers.Further exacerbating the need to gain knowledge of an adolescent's pre-adolescent behavior when taking into account juvenile justice practices, Moffit explains that adolescence-limited youths' antisocial behavior is normative, not abnormal. In fact, Moffitt references a study by Farrington, Ohlin, and Wilson in 1986 in which it is stated that four fifths of males have some contact with police for a minor infringement during their adolescent years. Based on self-report data, it is statistically abnormal to refrain from engaging in some type of antisocial or delinquent behavior.The aforementioned data points provide interesting insights into the nature of delinquency among adolescents. Approximately five percent of offenders have been repeatedly shown to be responsible for around fifty percent of known crimes. Moffitt's taxonomy suggests that this five percent is primarily comprised of life-course-persistent adolescents, and that these youth act as the gateway to delinquent behavior for adolescence-limited youths. It should be noted, however, that the theoretical causes for delinquent behavior between these two groups is quite different. Life-course-persistent antisocial individuals exhibit a number of characteristics that suggest psychopathology, with the root causes being related to subtle or underlying cognitive or neuropsychological deficiencies that become problematic through physical, social, and environmental influences. Adolescence-limited antisocial individuals, on the other hand, develop problematic behaviors as a result of a lack of socially ascribed maturity at a time when they develop biological maturity, and look to delinquent behavior as a way of achieving mature status.Taking into account the summarization provided, juvenile justice policies and practices must be flexible enough to account for two distinctly different types of antisocial individuals when considering sanctions. Such flexibility can only be achieved by successfully compiling data on juvenile offenders from as early in the life course as possible, preferably using multiple types of risk assessments from different sources, such as parents, caregivers, and educators. In addition, to truly intervene successfully in the lives of potential life-course-persistent antisocial persons, possible social, environmental, and physical influences must be identified when assessments indicate possible neuropsychological or physical deficiencies that have been shown to be linked to the development of criminal behavior. Such assessments would provide historical data regarding the levels of antisocial behaviors exhibited in youth across their developmental years and into adolescence, and would assist the juvenile justice system greatly in forming intervention and treatment plans that prove most successful without increasing the likelihood of antisocial continuity.SourcesMoffitt, T. E. (1993). Adolescence-Limited and Life-Course-Persistent Antisocial Behavior: A Developmental Taxonomy. Psychological Review, 100(4), 674-701.