My research program focuses on bullying, victimization, healthy relationships, and knowledge mobilization – moving research into practise and practise into research. Over the past 30 years, I have examined bullying and victimization from a developmental psychopathology perspective. I argue that this type of aggressive behaviour merits attention because it underlies many problems related to interpersonal violence. From a developmental perspective, the lessons learned in bullying within peer relationships generalize to other developmentally significant relationships, such as romantic and familial relationships. My current research projects include: understanding the biological, psychological, and social correlates of cyberbullying, peer victimization, peer defending and teen dating violence; investigating the role of shame in bullying and the associated mental health consequences; and evaluating knowledge mobilization of bullying research and its impact.