Addressing school bullying: Insights from theories of group processes ☆ Shelley Hymel ⁎, Robyn McClure, Miriam Miller, Ellen Shumka, Jessica Trach Faculty of Education, University of British Columbia, Vancouver, BC abstract article info Available online 26 December 2014 Keywords: School bullying Peer victimization Group processes Intervention Cooperative learning Collective efficacy In order to enhance efforts to address bullying in schools, and in response to the limited success of school-based anti-bullying programs to date, this paper considers bullying as a group phenomenon and explores theories of group processing that can inform future prevention and intervention efforts. Moving beyond efforts to reduce bullying by enhancing bystander responses, we consider research and theory addressing peer group socialization processes, the role of teachers as an “invisible hand” in structuring peer groups, social interdependence as applied to the design of cooperative learning environments, and collective efficacy. Although these theories are not in themselves developmental, and address group processes that operate across ages, they can inform both future prevention and intervention efforts and applied developmental research that explores the age-related contextual and individual factors that contribute to school bullying. © 2014 Elsevier Inc. All rights reserved. Bullying is recognized as a significant problem in schools worldwide (e.g., Jimerson, Swearer & Espelage, 2010; Pepler & Craig, 2008; Smith, Pepler & Rigby, 2004; Smith et al., 1999), with attention to bullying often borne of tragedy (Cullen, 2009; Godfrey, 2005; Marr & Fields, 2001; see also Submit the Documentary, www.submitthedocumentary. com; Bully Movie, www.bullymovie.com). Over the past few decades, increasing pressure has been placed on schools to address the issue and many have taken up the challenge, with no shortage of anti- bullying programs available (see Rigby, 2012; Sullivan, 2011 for overviews). Despite these efforts, rates of traditional forms of bullying appear to be declining only slightly (Currie et al., 2012; Finkelhor, Turner, Ormrod & Hamby, 2010; Rigby & Smith, 2011), and online bullying appears to be on the rise (Jones, Mitchell & Finkelhor, 2013). Al- though “evidenced-based practice” has become familiar mantra in edu- cation (e.g., Slavin, 2002), school-based anti-bullying interventions have met with mixed success. On the positive side, a handful of pro- grams that address bullying and victimization in different ways have documented significant, positive outcomes (e.g., Cross, Hall, Hamilton, Pinabona & Erceg, 2004; Frey, Hirschstein, Edstrom & Snell, 2009; Olweus, 1993; Salmivalli, Kärnä & Poskiparta, 2010a, 2010b), with whole-school approaches seen as most effective (Vreeman & Carroll, 2007). However, demonstrated effectiveness in one context is no guar- antee of success elsewhere (e.g., see Olweus, 1993, 1994 versus Roland, 2000, or Hanewinkel, 2004). Moreover, despite the documented efficacy of some programs, overall effect sizes have been small to negli- gible (Merrell, Gueldner, Ross & Isava, 2008; Smith, Schneider, Smith & Ananiadou, 2004), with one recent meta-analysis indicating reductions of only 17-23% on average in experimental schools, relative to compar- ison schools (Ttofi & Farrington, 2011). Thus, although there appear to be multiple ways to address bullying, and some demonstrated success in doing so, we have not yet identified all of the critical components of effective anti-bullying efforts, and need to remain open to new and dif- ferent approaches to addressing this complex problem. In their review of research on school bullying, Swearer, Espelage, Vaillancourt and Hymel (2010) offer several reasons for the lack- luster results reported for school-based anti-bullying programs to date (e.g., insensitivity of measures, implementation fidelity and dosage, etc). Two of the reasons they offered stand out as particularly significant – that anti-bullying interventions have not been well grounded theoret- ically, and have not seriously considered the social ecology in which bul- lying takes place. Accordingly, in this paper, we explore research and theory that focuses on group processes underlying bullying and how these can inform school-based anti-bullying efforts. We begin with a brief review of research that emphasizes peer group factors, and espe- cially the role of bystanders, on bullying behavior. Expanding this focus, we then consider theories of group processes and peer socializa- tion, and how each can provide insights and new directions for anti- bullying pre/intervention efforts. Specifically, we consider Harris' (1995, 1998/2009) Group Socialization Theory, recent research on teachers and classroom dynamics by Farmer et al. (2013), Deutsch's (1949, 1962) theory of social interdependence, as applied to coopera- tive learning (e.g., Johnson & Johnson, 2009), and, finally, Sampson's (e.g., Sampson, Raudenbush & Earls, 1997) theory of collective efficacy. These theories are not in themselves developmental. Rather, they are based on group processes that appear to operate across the life span, Journal of Applied Developmental Psychology 37 (2015) 16–24 ☆ Paper submitted for a special issue of the Journal of Applied Developmental Psychology on Bullying Prevention and Intervention, guest edited by Drs. Patricia Hawley and Anne Williford. ⁎ Corresponding author at: Faculty of Education, University of British Columbia, 2125 Main Mall, Vancouver, BC V6T 1Z4. Tel.: +1 604 822 6022. E-mail address: shelley.hymel@ubc.ca (S. Hymel). http://dx.doi.org/10.1016/j.appdev.2014.11.008 0193-3973/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Journal of Applied Developmental Psychology