Research on aggressive and abusive sibling dynamics has grown significantly but is characterized by a disjointed literature, confusion about the identification of harmful behaviors, and missed opportunities for increasing awareness and prevention and intervention activities. This paper proposes several important suggestions about the classification and differentiation of sibling aggression. First, there is a level of sibling aggression that merits the terminology of sibling abuse and is on a par with the severity of child abuse and spousal abuse within the larger rubric of family violence. Sibling abuse should be characterized as relationships involving repetitive ongoing emotional and physical violence, in a context of power imbalance, with signs of harm and intimidation. Second, there should be another category of sibling aggression that does not rise to the level of abuse, but still merits active intervention and repair. This is termed destructive conflict, which can be divided into mild and severe sub-categories. Severe destructive conflict entails aggression that is likely mutual and includes objects as weapons, injury, or threats of serious injury. In addition, we distinguish two categories that we would categorize as non-pathological: rivalry and constructive conflict. We assert that efforts to apply bullying terminology to sibling aggression have some important drawbacks and should be avoided. Research is needed to help confirm the utility of a classification of this sort. The proposed classification could enhance the cohesiveness of the research literature and lead to changes in professional practice, which often lacks training and access to evidence-based guidelines on sibling dynamics.
