Sibling sexual abuse: what do we know about definitions? Stage 2 analysis of a 2-stage scoping review

Sibling sexual abuse (SSA) is a common form of sexual violence within the family and as harmful as other intra-familial sexual abuse. However, there is a lack of consistent understanding of what SSA is. That siblings may engage in a range of sexual behaviours, including normative sex play, significantly complicates the identification of SSA. Furthermore, the changing nature of modern families and cultures adds complexity to defining a sibling relationship. Our comprehensive scoping review of the SSA literature (Yates et al., 2025) identified wide variation in the conceptualisation of sibling relationships and 27 different definitions of abusive sibling sexual behaviour. This lack of consensus creates confusion and inconsistency for how we identify, investigate and intervene in situations involving SSA. In this paper we critically examine the different definitions before proposing our own definition of SSA to support identification and appropriate professional responses, as well as greater consistency in research.