This commentary reviews the four articles included in a special issue of the "School Psychology Review" that address factors related to the bullying and discrimination among youth. The articles explore rather diverse topics within the broader literature on youth interpersonal violence, but each adds to our understanding of the very complex nature of bullying involvement. In an attempt to understand this complexity, we view these studies through the lens of a social-ecological diathesis-stress model (Swearer & Hymel, 2015), considering the individual, family, peer, school community, and societal contexts in which youth interpersonal violence occurs, and how biological and cognitive vulnerabilities interact with stressors like peer victimization to understanding the mechanisms at play in any particular incident of interpersonal violence. Together, the studies presented in this special issue contribute to our understanding of this complexity, reminding us that peers matter; educational placement matters; individual differences in race, sexual orientation, and disabilities matter; and measurement matters. It is perhaps this complexity that limits the effectiveness of current universal strategies for addressing such behaviors in school, but paves the way for more effective, multidimensional prevention and intervention efforts.