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. 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 R00 Pathway to Independence Award is to explore how bullying relates to altered reward processes, with a specific focus on how bully perpetration relates to preferences for absolute versus relative rewards. A primary focus of the R00 award will be focused on conducting bullying research translatable to intervention programming, by working with students, local schools, and community partners involved in youth violence and maltreatment services. During the K99, I received mentorship in hierarchical modelling youth behaviors, designing fMRI tasks for youth that assay specific mechanisms, and leveraging findings from research into feasible interventions with broad crosslevel (youth, parent, school, agency) buy-in. The K99 clarified the role of specific risk factors for bully perpetration, how bully perpetration related to absolute reward responses, and included the successful piloting of both a behavioral and neuroimaging task which differentiated the preference and processing of absolute versus relative rewards. The training and results from the K99 now allow for the successful completion of the R00 proposal, which tests how bullying behaviors during childhood and adolescence relate to the preference for relative vs. absolute rewards in a larger, well-phenotyped sample. I will test whether bullying predicts increased behavioral preference and neural response to relative vs. absolute rewards, while assessing for specificity. Results will clarify reward processing alterations related to bullying, examine the specificity of these associations compared to other phenotypes, and examine relative reward preference as an explanatory factor of bullying in relation to other theoretical risk factors. The data collected during the R00 proposal will clarify reward mechanisms underlying bully perpetration and set the stage for a future R01 focused on the neurodevelopment of relative reward preferences, the stability of different reward preferences, and their malleability to intervention. This proposal addresses important concerns...