The aim of this study was to investigate potential factors of why children and youths generally start bullying, but also the long and short-term effects bullying has on its victims. In order to answer the research questions, the method used was a systematic literature review which includes collecting data by using databases such as Libsearch and Swepub. We obtained seven studies including doctoral dissertations and scientific articles, some of which include collected data results from several longitudinal, quantitative, qualitative and meta-analytic studies. The theoretical framework used in this study include social cognitive theory by social psychologist Albert Bandura. This theory was relevant in order to analyze how bullying behavior can be designed based on the social environment together with cognitive abilities. The results indicate that bullying is a complex phenomenon explained differently within the research field and our main finding shows that the victims define bullying differently from the definition used by researchers within the field. Several different factors emerged as to why some children and youths are prone to bullying. This study identifies that some of these factors are due to moral disengagement which refers to distancing from moral actions and lack of moral emotions such empathy, sympathy and guilt. Furthermore, domestic violence and social environment such as aggressive peers are also explanatory factors to why children develop and normalize a bullying behavior. Finally, this study has shown that bullying affects the victims at both early and adult age. Bully victims are often being affected in an early age developing mental health issues such as depression, anxiety, low self-esteem and increased risk for behavioral problems associated with substance use. These problems often continue into adulthood where beside mental and physical health issues the victims also struggle with trust and relationship issues.