Factors associated with bystander intervention in cyberbullying: a systematic review.

Introduction: Cyberbullying among adolescents often takes place in front of an online audience, yet many bystanders remain passive. Evidence on factors associated with intervention is dispersed across psychological, relational, contextual, and platform-related areas. Methods: Following PRISMA 2020 and PRISMA-S, we searched Web of Science Core Collection, Scopus, ScienceDirect, SpringerLink, PubMed, and IEEE Xplore, together with citation searching and Google Scholar, for empirical studies published from 2018 to June 2026. Database searches identified 1,244 records and yielded 41 included reports; citation searching and Google Scholar identified eight additional reports, resulting in 49 reports overall. Conclusions about adolescent intervention were anchored in a 42-report core corpus, with seven reports at the population, phenomenon, or outcome boundaries examined separately. Included reports were appraised using the Mixed Methods Appraisal Tool (2018 version) and synthesized through a structured narrative approach across six a priori factor domains without meta-analysis. Results: The most consistent evidence concerned individual psychological resources, especially empathy, defender self-efficacy, and constructive moral orientation. Incident appraisal and relational, family, and school ecology were linked to intervention more conditionally, while demographic, sociocultural-normative, and platform-design factors were mixed or sparse. Most reports used cross-sectional designs and self-report measures, and the evidence was concentrated in a limited number of national settings. Discussion: The findings can be organized in a staged ecological framework moving from recognition and incident appraisal to moral-emotional activation, efficacy and norm calibration, and action selection. They may inform empathy and efficacy training, safe reporting routes, and supportive school, family, and peer conditions in adolescent school settings similar to those represented in the evidence; platform-level and cross-cultural applications require local adaptation and direct testing. Systematic review registration: https://doi.org/10.17605/OSF.IO/68CMH, identifier: OSF.IO/68CMH.