What Do We Know?
Simply, not enough.
Sibling sexual trauma is common, but hidden.
The best estimate based on current research is that only about 12% of those who are affected by sibling sexual trauma ever tell anyone about it . But, it is impossible to truly measure how many never tell, even anonymously to a researcher.
With that in mind, 5WAVES estimates that at least 3-5% of children are sexually harmed by a sibling . This means that a child is about as likely to experience sibling sexual trauma as to have a food allergy .
Leading researchers suspect that sibling sexual trauma is one of the most prevalent forms of child sexual abuse .
 Finkelhor 1980, Townsend 2016
 Finkelhor 1980, Strong 2022, Relva 2017, Cawson et al 2000, Stroebel et al 2013,
 Yates & Allardyce, 2021, SARSAS/Strong, 2022, Stathopoulos, 2012, Bertele & Talmon 2021
Sibling sexual trauma is real. It is different than "playing doctor," but hard to distinguish. The consequences are serious and lasting.
Sibling sexual harm starts earlier, lasts longer, and is more frequent and severe than other child sexual abuse. In half of all cases, the harm to a child begins before their 8th birthday, and lasts more than 5 years .
The consequences of sibling incest are as serious for the survivor as adult-child incest. They include anxiety, depression, shame, Complex PTSD, difficulty maintaining stable and trusting relationships, stress-related pain and physical illness, increased risk for substance addiction, eating disorders, self-harm, suicide, sexual exploitation and victimization into adulthood .
Children who bear the responsibility for sexually harming a sibling, or who felt at the time that they were a willing participant, are still likely to suffer lifelong negative consequences including shame, depression, anxiety, low self-esteem, and increased risk for suicide and addiction .
Adults, including parents and professionals, find it difficult to accurately assess and appropriately respond when they learn of sexual behavior in children. In a survey of professionals who respond to reports of child sexual abuse in the UK, 73% reported they had received inadequate training about sibling sexual behavior, with many reporting no education or training whatsoever .
 Kreinert and Walsh 2011, Finkelhor 1980, Bertele and Talmon 2021, deJong 1989
 Carlson, 2011, Cyr et al 2002, Falcao 2014, Katz et al 2020, Laviola 1992, Rudd & Herzberger 1999, Shaw et al 2000
 Marmor & Tener 2022, Tener et al 2017, Kjellgren2017, Allardyce & McAfee 201
 Noble, 2022, Sibling Sexual Abuse Professional Survey Report
Children and teens who cause sexual harm to their siblings need to take responsibility, need extra guidance, supervision and professional help. However, they are unlikely to be pedophiles or to continue to sexually harm children into adulthood.
More than ⅓ of sexual harm to children is caused by other children or teens .
Although the harm to their siblings is serious and real, and the short-term risk for relapse is real, factors that lead children and teens to make this tragic choice are very different than for adults who sexually abuse children .
Less than 10% of adolescents who commit any sexual offense will be arrested for another offense as an adult . Studies are needed that look at risks specifically for those who have sexually harmed a sibling.
 Finkelhor, et al 2009, Hackett 2013, Grant et al 2009, Snyder 2000, Gerwitz-Meydan & Finkelhor, 2019
 Przybylski 2015, Grant et al 2009, Hackett et al 2013, Lussier & Blokland 2013, McKibbin 2017, McKillop et al 2015, Worling 2013
 Caldwell 2010, NSPCC 2021, McKillop 2015, Boyd & Bromfield 2006, Letourneau 2008, Przybulski 2015