PROJECT ABSTRACT Bullying is the most common form of youth abuse world-wide and is linked to profound, lasting, deleterious effects to psychological, social, academic and health functioning. The cascading effects of bullying costs the US billions of dollars annually, and current interventions produce only modest improvements. Longitudinal examinations of the course of bullying show that behaviors vary over childhood, though early perpetration is thought to be a particularly troubling predictor of continued antisocial behavior. A recent bullying intervention targeting altered reward processes, specifically a preference for relative rewards (e.g. those earned at the expense of others) shows promise. However, how trajectories of bullying relate to altered reward processing, and how perpetrators process relative rewards in comparison to absolute rewards (e.g. money or points earned) is currently unknown. Explicating the biobehavioral reward mechanisms contributing to bully perpetration may allow for the design and implementation of more biologically-informed, empirically-supported interventions that can provide greater reductions in bullying. The goal of this K99/R00 Pathway to Independence Award is to provide the applicant with the training in longitudinal data analysis techniques to explain how trajectories of bullying relates to altered reward processes, as well as training in designing fMRI tasks to identify altered reward mechanisms related to bullying. Additionally, a primary focus of my training will be to conducting bullying research translatable to intervention programming, by working with my co-mentor in interfacing with multiple agency stakeholders involved in youth violence and maltreatment. To achieve these goals, I have assembled a committee that will provide unparalleled mentorship, whom have extensive backgrounds in longitudinally modelling youth behaviors (Drs. Barch, Jonson-Reid, Jackson, Luby, and Vaillancourt), designing fMRI tasks for youth that assay specific mechanisms (Drs. Barch and Sylvester), and who have experience leveraging findings from research into feasible interventions with broad cross-level (youth, parent, school, agency) buy-in (Drs. Jonson-Reid, Barch, Luby, Vaillancourt, and Glenn). These training goals will allow me to test predictions about trajectories of bullying in relation to absolute reward processing and pilot tasks capable of assessing relative and absolute reward preference during the K99 phase. Results learned from this will inform the R00, where I will test whether trajectories of bullying predict preference for relative vs. absolute rewards and if bullying predicts increased neural response to relative vs. absolute rewards. Results from this proposal will clarify reward processing alterations related to bullying, examine specificity to other behavioral problems, and examine relative reward preference in relation to other explanations of bullying, setting the stage for the testing of an intervention ...