A Developmental Taxonomy of Juvenile Sex Offenders for Theory, Research, and Prevention: The Adolescent-Limited and the High-Rate Slow Desister

The current study investigates the offending trajectories of juvenile sex offenders (JSOs) across and beyond adolescence. In doing so, the study examines the number, the rate, and the shape of nonsexual and sexual offending trajectories in a sample of JSOs followed retrospectively and prospectively from late childhood to adulthood. Using semiparametric group-based modeling, the study reveals the presence of five distinctive nonsexual offending and two sexual offending trajectories: adolescent-limited and high-rate slow desisters. The study does not find strong evidence of synchronicity between nonsexual and sexual trajectories, suggesting that the current taxonomy of antisocial behaviors may offer a limited perspective on sex offender types. Furthermore, sexual trajectories do not differ much across sex offender types, suggesting that the findings might be generalized to child and peer abusers. The study findings offer supporting evidence for the presence of two distinct JSO types with important implications for theory, research, and interventions

Interaction effects in multielement designs: inevitable, desirable, and ignorable.

A single-subject design often used to compare the effectiveness of two or more independent variables (like treatment programs) is the multielement (alternating treatments or simultaneous treatments) design. Variants of this design approximate the concurrent comparison of the effects of two or more variables (or levels of variables) by programming the variables (or levels) in rapid alternation, typically across or within daily sessions. Properly combined with conventional reversal designs, these designs can also display a variety of interaction effects, some of them worrisome, others highly desirable for the future development of the field. A worrisome model is the possibility that when Treatment B alternates rapidly with Treatment C, the effects of each will not be the same as when each is the only treatment used. A desirable model is the use of the multielement design as a fast-paced component of an otherwise conventional reversal design examining contextual control of some relationship; the possibility that some behavior responds differently to Controlling Variables A and B in Context X than in Context Y. This second possibility opens single-subject designs to the more efficient examination of all interactive effects and is highly desirable, considering the prevalence and importance of interactions in determining the limits and the generality of currently understood behavioral phenomena