This dissertation is part of a research project entitled, The social and moral processes of bullying (grant no. D0775301). The purpose of this project was to examine bullying and bystander behaviours from the perspective of pupils. All research discussed has undergone ethical review (Dnr 2015/342-31, and Dnr 2019-01507). All names of schools, teachers and pupils have been replaced by pseudonyms to ensure confidentiality.I would like to give a special thanks to the pupils who shared their experiences, and who thus not only made this work possible but also, through sharing their experiences, became an important part of the continuous work to prevent bullying in schools. I would like to thank the principals and teachers of the participating schools, not least for their helpfulness, curiosity, and commitment.Thanks to Helene Elvstrand for agreeing to be the opponent at my 60% seminar, for your reading and for your constructive suggestions in developing the texts. Thanks to Ylva Odenbring for agreeing to be a reviewer at my 90% seminar, and for your careful reading and your comments and suggestions for improvement. Thanks to Ann-Marie Markström and Lina Söderman Lago for taking the time to be part of the reading group, and for your careful reading, which has significantly improved this work.Thanks to my supervisors, Paul Horton and Robert Thornberg. You have both been very supportive and helpful and let me take great responsibility for the implementation of this work. Through your support and your trust in me, I have been able to grow not only as a researcher and teacher, but also as a person. Thanks also to my colleagues at the IBL Division of Education, Teaching and Learning. I have greatly appreciated being your colleague during the years of this work! Thank you, Johan Forsell with whom I shared an office for six years. It has been uplifting to discuss everything from Bauman to Thåström, and I have greatly appreciated having someone to share the challenges and hopes of writing a dissertation in order to become a "real" researcher. Thanks also to Michael Tholander for the uplifting conversations, and for the film, series, and literature tips over the years. I have really enjoyed getting to know you! I want to thank my family -Eva-Marie, for always being there for me, and for helping me with whatever I needed help with. Johan, my older brother, for all the tips on how to manage life, for letting me know about good restaurants in Stockholm, and for your help with the cover photo of this dissertation! A special thanks also to my siblings, Elias, Jenny, and Alex! Thanks to Kenneth, for all the conversations about life in academia, about scientific theory and practice, for reading my texts, and for all the evenings listening to vinyl together. Thank you, Margareta and Per, for the summers at Åstol, and for being such caring grandparents to John and Vilhelm. Thanks to Karin for helping me understand academia, for all your time reading my early drafts, and for being such a loving mother to John and Vilhelm. Lastly, I want ...