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Children’s Physiological and Emotional Reactions to Witnessing Bullying Predict Bystander Intervention


  • This research was supported by a Belfer-Aptman Dissertation Award from The Melissa Institute. The authors would like to thank Jean-Phillipe Laurenceau for his statistical consultation, as well as the project’s undergraduate research assistants for their hard work and dedication. Most of all, they appreciate the help of the children, parents, teachers, and principals who made this project possible.

concerning this article should be addressed to Julie A. Hubbard, Department of Psychology, University of Delaware, Newark, DE 19716. Electronic mail may be sent to


Study goals were to explore whether children clustered into groups based on reactions to witnessing bullying and to examine whether these reactions predicted bullying intervention. Seventy-nine children (= 10.80 years) watched bullying videos in the laboratory while their heart rate (HR) was measured, and they self-reported on negative emotion after each video. Bullying intervention was assessed by school peers. Two groups emerged based on reactions to the bullying videos: The Emotional group (43% of children) displayed HR acceleration and reported high negative emotion, whereas the Unemotional group (57% of children) showed HR deceleration and reported low negative emotion. Group membership predicted bullying intervention, with peers reporting that Emotional children were more likely to stop a bully than Unemotional children.