Positioning sibling sexual behaviour and abuse: using KPI and mapping frameworks to advance understanding, research, policy and practice

Sibling Sexual Behaviour and Abuse (SSB-A) is increasingly recognised as both a prevalent form of intrafamilial sexual abuse and a significant subtype of Harmful Sexual Behaviour (HSB) between children and young people. Evidence from research and practice demonstrates that SSB-A is situated within a complex context of individual, relational and familial dynamics, often underpinned by dysfunction. SSB-A remains under-theorised and inconsistently addressed in policy and practice frameworks. This paper draws together existing evidence to conceptualise SSB-A as a distinct form of HSB and uses an SSB-A-specific KPI tool and the Sibling Sexual Behaviour Mapping Tool (SSB-MT) to support its identification, prevention and response. While sexual behaviour between siblings is never developmentally appropriate, it can manifest across a spectrum of severity, ranging from problematic to harmful, requiring nuanced understanding and differentiated professional responses. Grounded in the socio-ecological model, this framework provides a structured means for professionals to locate SSB-A within wider systems of risk, need and support.PRACTICE IMPACT STATEMENT The Sibling Sexual Behaviour Mapping Tool and Key Performance Indicator evaluation framework, combined, endeavour to offer structured, trauma-informed tools that support practitioners in assessing, planning and evidencing responses to sibling sexual behaviour/abuse. They enhance multi-agency collaboration, improve safeguarding and service delivery, enabling professional reflection, intervention and effectiveness across complex family contexts.