Department of Educational Psychology


Date of this Version



Published as Chapter 7 in: T. W. Miller (ed.), School Violence and Primary Prevention (Springer, 2023), pp. 199–216.



Copyright © 2023 Dorothy L. Espelage and Susan M. Swearer, under exclusive license to Springer Nature Switzerland AG. Used by permission.


Bullying, a subset of aggression, has been an international focus of scholarship for several decades and has been declared as public health concern globally (Espelage, 2015; Hymel & Espelage, 2018; Kann et al., 2018). An abstract literature search with the terms “adol*” and “bully*” yielded 382 peer-reviewed journal articles from 2001 through 2010, and an astounding 1585 articles from 2011 through 2020.

Within the last decade, there has been a concerted effort among scholars to reach a consensus on how bullying should be defined, operationalized, and assessed, how it differs from other forms of aggression (e.g., dating violence), and how it relates to other forms of violence across early and late adolescence (Rodkin et al., 2015; Volk et al., 2017). In 2011, the US Centers for Disease Control and Prevention (CDC) convened a group of international scholars and unanimously agreed that “Bullying is any unwanted aggressive behavior(s) by another youth or group of youths who are not siblings or current dating partners that involves an observed or perceived power imbalance and is repeated multiple times or is highly likely to be repeated. Bullying may inflict harm or distress on the targeted youth including physical, psy­chological, social, or educational harm” (Gladden et al., 2014, p. 7).