Sibling Sexual Behavior is Different

Three sibling sexual abuse advocates walk into a bar… Not a likely start for an academic journal article, but that’s how it happened.

In May 2024, all five 5WAVES cofounders traveled to Birmingham, England to present at the NOTA International Conference. Maria, Jane, and Brandy were still there for the final social event, at a local drinking establishment. In attending the conference, we had been eager to meet leaders and researchers whose names we knew only from reading reports and articles–and NOTA International did not disappoint. However, as the conference ended, there was one person we had yet to meet: Simon Hackett, PhD. Just as we were ready to head back to our rooms and get ready to travel back to the US, one of our new UK contacts pointed him out to us. And the rest, as they say, is history. 

We were particularly keen to meet Simon, because of his role as the creator of the “Hackett continuum,” a graphic portraying the range of children’s sexual behavior that has been widely used in practice guidance on responding to all types of children's sexual behavior, including sibling sexual abuse. Brandy, a parent of sibling sexual trauma, had been relieved to find that it validated a truth she had sensed but that her state’s laws did not recognize: that not all children’s harmful sexual behavior should elicit the same response as adult sexual abuse of children should. But to Maria, a survivor, the continuum did not sit well–especially when her brother’s behavior, which had caused her decades of pain and trauma, would not be labeled as "abuse" under the Hackett continuum, and thus could be easily dismissed or minimized. So, from the day we arrived in Birmingham, she had been looking for an opportunity to meet the creator of this continuum, to hear what he had to say about her concerns. 

To our pleasant surprise, when we finally did introduce ourselves to Dr. Hackett, we found him to be a delightful, gracious, compassionate man–who agreed with Maria that the illustration he had created was being mis-used. He explained that it was created for the purpose that Brandy appreciated, but was never meant to be a continuum of harmful sexual behavior, nor to be used in the context of evaluating the needs of children who had been harmed, nor to be used in the specific context of sibling sexual behavior. 

Thus, a dialogue began, joining with two more leading voices in SSTA research and practice: Stuart Allardyce and Peter Yates. Over the course of many months of Zooms and emails, we all discussed and debated. Then for many more months we drafted, submitted, and revised an article that would share our collective clarifications and advice with the world. Now that article has been published, appropriately, in NOTA’s own Journal of Sexual Aggression. The summary below outlines the main points of the article. 

When it comes to evaluating and responding to sibling sexual behavior, context is everything. Sibling sexual behavior is different than other types of children's sexual behavior, in the following ways that practitioners and parents must not ignore.

1. Behavior that is normal between peers is not necessarily normal between siblings. (An example of this would be mutual experimentation between teens who are past puberty.) Therefore, responders should not use tools designed for evaluating peer-to-peer behavior, when siblings are involved.

   
   

2. Any behavior that does not meet all the criteria for normal body curiosity between siblings (see list below) should be evaluated as potentially harmful, for all siblings involved

   

3. Resist the tendency to assume that sexual behavior between siblings is consensual.

   1. Children cannot give consent.

   2. Sibling power dynamics can be subtle or hidden to adults, yet real.

   3. This can subtly add to children’s false beliefs that they are at fault, which adds to ongoing trauma.

      
      

4. Harmful sibling sexual behavior exists within a specific family and sibling relationship, and cannot be understood or navigated apart from that family. 

   1. Family dynamics and sibling relational difficulties may have played a role in the pathway leading to the harmful behavior.

   2. Betrayal trauma adds to the harmful effects of the behavior, even when previous relationships were positive.

   3. Parents are responsible, in the midst of their own traumatic experience, for supporting and caring for all children involved, which brings significant practical and emotional challenges. 

   4. Family relationships last a lifetime and therefore must be navigated in the long term.

   5. The stigma associated with incest tends to limit support from outside the family.

      
      

5. Each child’s needs must be assessed separately. (see graphic below) Yet adults need to be aware that decisions made on behalf of one child are likely to affect the other(s). The impacts, needs, and ongoing welfare of at least two children must always be kept in view. 

   1. The severity of behavior does not determine the severity of the harm. Each child’s need for intervention must be assessed separately.

   2. The age or intent of the person displaying the behavior does not determine the level of impact on the other child involved. 

   3. The impact of the behavior and the level of trauma present in all children may not be immediately apparent. 

   4. Each child’s need for physical and emotional safety must be held in ongoing balance with the benefit of living in a supportive family environment. 

To read the full article: Full citation: Socolof, M., Hackett, S., Allardyce, S., Yates, P., Black, B., & Epstein, J. (2026). Sibling sexual behaviour is different: towards a conceptual framework of harmful sexual behaviour among siblings. Journal of Sexual Aggression, 1–14. https://doi.org/10.1080/13552600.2026.2704741

For those without institutional access to the journal, the accepted manuscript is also available at: https://researchonline.gcu.ac.uk/ws/files/114975418/114725799.pdf