Standing Up or Standing By: Examining the Bystander Effect in School Bullying

School bullying represents a serious mental health problem for youth in the United States. Bullying is a social phenomenon that is affected by the social context in which it occurs. Bystanders (i.e., individuals who witness bullying), are present in the vast majority of bullying situations. When bystanders choose to intervene on behalf of the victim, they are able to stop the bullying about 50% of the time. Unfortunately, bystanders rarely stand up for victims, instead frequently choosing to help the perpetrator or passively observe the bullying situation. Researchers have identified the bystander effect (i.e., the inhibitory effect of other bystanders on any given bystander's likelihood of helping others) as one of the primary causes of passive bystanding in adults. However, this research has not yet been applied to youth who witness bullying. Using an experimental vignette research design, this study examined if the bystander effect explains active versus passive bystanding behavior among high school youth. Additionally, important moderators of the bystander effect were tested including the number of bystanders present, the relationships between bystanders and the participant, the type of bullying being perpetrated, and the sex of the victim. The results did not provide evidence for the bystander effect in adolescence. However, both individual differences (i.e., participant sex, empathy) and situational factors (i.e., type of bullying being perpetrated) were found to affect hypothetical bystander helping behavior. These results may serve to inform intervention efforts seeking to encourage adolescents to stand up for their peers. iv ACKNOWLEDGEMENTS No doctoral student gets to be where they are without tremendous levels of support from those around them. I would like to thank my advisor, Dr. Susan Swearer. Her guidance, leadership, and mentoring has had a tremendous influence on my research and my career. From the beginning, she encouraged me to pursue my goals, and when I needed support, she was always there to provide it. Dr. Swearer's efforts have been instrumental in this project's success, from helping me finalize my methodology, to coming with me to meet with school principals, to rallying the research team around me when a final push was needed. I would also like to thank my dissertation committee members, Drs. Eric Buhs, Cynthia Willis-Esqueda, and Reese Peterson. Their collective influence and expertise has been extraordinarily valuable. I would like to thank Dr. Buhs for excellent insight into methodological improvements and his early influence on my career path. I thank …