Children's social lives — and their academic lives go hand in hand, whether or not they have friends, whether they are accepted or rejected by their peers, or whether they are victims or perpetrators of aggression. This means that we cannot fully understand the factors that lead to academic achievement without knowing about the social environment of children in school. Bullying can have long-term effects on students' academic achievement. Commonly labeled as peer victimization or peer harassment, school bullying is defined as physical, verbal, or psychological abuse of victims by perpetrators who intend to cause them harm. The critical features that distinguish bullying from simple conflict between peers are: intentions to cause harm, repeated incidences of harm and an imbalance of power between perpetrator and victim. This definition of school bullying does not include more lethal sorts of peer-directed hostilities. Although some widely-publicized school shootings may have been precipitated by a history of peer abuse, they remain rare events. The focus of this module is on more typical and widespread types of bullying that affect the lives of many children and that have been labeled as a public health concern by the American Medical Association.