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Practice guide

October 2012

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Sibling sexual abuse is a hidden and often under-reported form of sexual abuse. Studies indicate that sibling sexual abuse is more prevalent than other types of intra-familial sexual abuse. Due to the mostly close relationship and physical proximity between siblings, sibling sexual abuse is considered an opportunistic form of abuse. Abusive siblings are often displaying problematic sexual behaviours or developmentally inappropriate behaviours that may be the result of victimisation they have encountered themselves - either witnessed or experienced. Abused siblings often do not disclose being abused due, among other things, to fear of not being believed, fear of upsetting parents, or confusion over their role in the abuse. Current therapeutic frameworks suggest providing counselling for the whole family.

Key messages

  • Sibling sexual abuse is more prevalent than other forms of intra-familial sexual abuse.

  • There are significant barriers to disclosure for children who are being abused by a sibling.

  • The impacts of sibling sexual abuse can be similar to other forms of sexual abuse.

  • Young people with problematic sexual behaviours require not only legal, but also therapeutic interventions.

  • Parental support of all children involved in sibling sexual abuse contributes to greater therapeutic outcomes.



Despite an indication in the literature that sibling sexual abuse is the most prevalent form of sexual abuse, little is known about its impacts on abused siblings, abusive siblings and the families involved. This Research Summary into sibling sexual abuse will review the current literature on definitions, impacts, barriers to disclosure and legal issues in order to highlight this often hidden form of sexual abuse. The review will also explore the literature on implications for therapeutic interventions - particularly the shift in thinking about sibling sexual assault and the abusive sibling from a punitive response to a much more therapeutic response.

Sibling sexual abuse remains a hidden and under-reported form of sexual abuse, relative to other forms (Caffaro & Conn-Caffaro, 2005; Welfare, 2008). Definitions of sibling sexual abuse are varied and range from cultural, to therapeutic through to legal understandings. The literature suggests that definitional inconsistencies can create difficulties in understanding abused siblings, abusive siblings and incident characteristics that can assist in therapeutic interventions (Krienert & Walsh, 2011).

Small-scale qualitative studies indicate that due to a lack of disclosure and reporting, prevalence rates for sibling sexual abuse are unclear (Caffaro & Conn-Caffaro, 2005; Carlson, Maciol, & Scheider, 2006). The reasons for non-disclosure by the victim/survivors share similarities with personal barriers to disclosing other types of sexual abuse. However there are specific barriers related to the sibling relationship.

Impacts of sibling sexual abuse are similar to other forms of child abuse (Welfare, 2008). Impacts can be predicated on the type of responses the abused sibling receives from family members, authorities and/or therapeutic agents after disclosure - such as disbelief and denial or conversely belief and support (Caffaro, 2008; Rowntree, 2007; Women's Health Statewide, 2005). The problematic sexual behaviour of the abusing sibling may be enabled by the impacts of past victimisation and/or abusive relationships within the family, whether witnessed or experienced.

Current therapeutic responses to sibling sexual abuse consider a holistic, whole-of-family approach to be the most effective strategy toward recovery for all (Caffaro, 2008; Kambouridis & Flanagan, 2003; Welfare, 2010).

Due to a paucity of research concerning sibling sexual abuse, there is literature referenced here that relates to research conducted in the late 1980-90s. However, in more recent years sibling sexual abuse has begun to interest researchers and some reports and studies have been generated. This is due in part to clinical workers conducting research in order to bring the issue to light in response to their clients. This review also contains literature concerning problematic childhood sexual behaviours and the mental, physical and social sequelae of childhood sexual abuse.

The literature pertaining specifically to sibling sexual abuse summarised within considers work from international studies and Australian research. There is one case study included, some small clinical studies and retrospective studies conducted with adult victim/survivors and adults who abused their sibling/s in childhood. One of the most recent and comprehensive pieces of research is based on national police data, and comes from the United States.

Brief history - cultural and therapeutic

Brief history - cultural and therapeutic

A brief historical overview of the predominant cultural and therapeutic beliefs associated with sibling sexual abuse illuminates why there is a paucity of research and why sibling sexual abuse remains a hidden form of abuse (Welfare, 2008). Sexual relations between family members is strictly taboo (Rayment & Owen, 1999). The taboo goes as far back as the ancient Greeks (Pasco, 1995). However, there is evidence that sibling sexual abuse has been somewhat romanticised in the past, mainly in Romantic1 literature (Pasco, 1995; Rowntree, 2007). Culturally, sexual contact between siblings has been thought to contain innocent elements of age-appropriate sexual exploration. This perhaps reflects a belief that sexual activity between young children is consensual, benign, without malice or without harm (Welfare, 2008).

It is only relatively recently that treatment guidelines for sexual abuse of any kind have been developed. The earliest treatment guidelines for father-daughter incest relied on Freudian constructions of the repressed sexual longings of children (Welfare, 2010). Welfare noted that based on Kinsey's reports of the time,2 a view was held by medical practitioners that the sexual abuse of children did not cause them harm.

By the 1970s, feminist theorists and clinicians began developing therapeutic techniques focused on the victim of abuse (Welfare, 2010). There was a denial of the therapeutic needs of the abusing sibling however, and the view was that it was better to separate the family indefinitely than to risk the safety of the victim. From the 1980s until the early 2000s therapeutic approaches characterised children who had sexually abused a sibling/peer as though they were adult sex offenders (Pratt, Miller, & Boyd, 2010). This meant that the theories and treatment strategies used were similar to those for treating adult paedophiles.


1 According to Brown (2012) "romantic literature branched out from the world of natural science, mathematics and logic, creating a new style of writing that focused on human emotion and expression" (para. 1).

2 See Kinsey (1948 and 1953).

What is sibling sexual abuse?

What is sibling sexual abuse?

Exactly what constitutes sibling3 sexual abuse is a matter of contention and confusion for abused siblings, abusing siblings, family members and professionals (Hatch & Hayman-White, 2001; Pratt et al., 2010; Rowntree, 2007). There are some indicators that may be useful in the identification of sibling sexual abuse for parents and professionals, however they are marked by inconsistencies between studies and cover cultural, therapeutic and legal frameworks. Krienert and Walsh (2011) suggested that definitional inconsistencies create fractured knowledge that restricts policy-makers and therapeutic agents "from making informed decisions in the interest of reducing the prevalence and scope of sibling sexual abuse" (p. 350).

Following is a discussion of the most debated and significant aspects related to defining sibling sexual abuse contained in the reviewed literature.

Age difference between the abused and the abuser

One of the most widely cited research studies into childhood sexual abuse was conducted by Finkelhor (1980) who based his definition of sexual abuse between children on differences in age (Rayment & Owen, 1999). The age gap that constituted abuse was 5 years or more. There is still debate around how big the age difference is before mutuality gives way to coercion but much of the literature indicates between 2-5 years difference (Carlson et al., 2006).

Many current studies have found that children with problematic sexual behaviours are usually older than their victims (Krienert & Walsh, 2011; Monahan, 2010). In an Australian clinical sample study of 17 young women abused by their siblings, Welfare (2010) found that the average age difference was 4.18 years. In another Australian study based on outcomes for the abusing child, Rayment-Hugh and Nisbet (2003) defined a child victim as a person under 13 years of age, and at least 3 years younger than their abuser. Monahan (2010) echoed this age difference and distinguishes consensual sex play from coercive sibling sexual assault on a difference of more than 3 years.

Although age difference may be a good indicator in coercive sexual contact between children it is dangerous to ignore the fact that there can also be coercion between children of a similar age and McVeigh (2003) warned that age should not be the only indicator. If the abusing child is physically larger than the victim they may use this strength to physically intimidate their victim, or they may just rely on threats.

Further, as cited in Hatch and Hayman-White (2001), age is of little consequence when sibling victims are chosen on the basis of their vulnerability, such as isolation, parental neglect, emotional dependence, smaller physicality or disability. A large-scale national US study of police reports of sibling sexual abuse noted that verbal coercion and/or manipulation were common tactics used by siblings (Krienert & Walsh, 2011).

Coercion and violence

Although violence is not always present in sibling sexual abuse, coercion is certainly considered an identifying factor. The same national study cited above found that the use of weapons in sibling sexual abuse, although common in their national sample, usually indicated the abusive sibling used their hands and feet to subdue their victim (Krienert & Walsh, 2011). The most common forms of coercion found in sibling sexual abuse incidents were verbal coercion, threats and bribery/trickery (Carlson et al., 2006; Hatch & Hayman-White, 2001).

In one case study, a young girl was "tricked" into sexual acts by her brother who originally offered physical comfort through hugs and other non-sexual physical contact and eventually escalated the physical contact to include sexual acts (Ballantine, 2012). He did not need to coerce her more forcefully as she was vulnerable due to her "harsh family environment … and the family's low opinion of her" (p. 60) which had left her with poor self esteem and desire for acceptance.

However there are also studies that found child sexual abuse can involve physical coercion and an escalation in forced sexual acts (Paine & Hansen, 2002). For example, the abuse may begin with unwanted sexual comments to unwanted genital touching and evolve to forced penetration (Carlson et al., 2006).

In a study based on a sample of 41 victim/survivors of sibling sexual abuse - both men and women - 68% reported coercion, threats and/or bribery, 10% were threatened with physical violence and 5% indicated "threats to withhold privilege or offers of money or gifts" (Carlson et al., 2006, p. 27). Another study with 43 victim/survivors of sibling sexual abuse found 25% had been coerced through physical force, 11% with verbal threats, 32% with bribery/trickery and the remaining had a combination of physical/verbal, physical/bribery and verbal/bribery coercive tactics used against them (Hatch & Hayman-White, 2001).

Developmentally inappropriate sexual behaviour

Developmentally inappropriate behaviour and problematic sexual behaviours can be distinguished as two categories, although there is cause to consider some overlap between them. For the purpose of this paper they will be separated and problematic sexual behaviour will be presented in the section below. Although a distinction is being made, both can be present in a child who has been victimised in the past. A child who has been abused by a sibling may present developmentally inappropriate behaviour and problematic sexual behaviour, and a child who displays abusive behaviours toward their sibling/s may be acting out either developmentally inappropriate behaviour or problematic sexual behaviour.

Developmentally inappropriate sexual behaviour refers to behaviour that is not in line with a child's physical and mental development. It can be a result of a family environment that allows exposure to highly sexual language and media or is extremely tolerant to sexual contact and activity (Hatch, 2005).

An Australian Crime Commission report (O'Brien, 2008) cautioned that more research is needed into child sexuality in order to understand what is and is not developmentally inappropriate. However any definitional categories contain the risk of pathologising childhood sexuality by determining too stringent guidelines as to which behaviours are appropriate for which age groups (O'Brien, 2008). O'Brien warned that "researchers need to resist the apparent comfort offered by fixed definitions or exhaustive lists" (p. 8). Nonetheless, some broad definitions are included in the report and are presented below in Table 1.

Problematic sexual behaviours

Unlike the discussion on developmentally inappropriate/appropriate behaviours, a discussion of problematic sexual behaviours concerns the use of coercion, intimidation and lack of consent (McVeigh, 2003). There is an element of secrecy in sibling sexual abuse that is enforced by the child with problematic sexual behaviour - as well as a power dynamic (McVeigh, 2003). The field of study related to child and adolescent problematic sexual behaviours is becoming more relevant as the high prevalence of child sexual abuse becomes known and issues of how to respond to children who display problematic sexual behaviours are discussed. Two recent reports by the Australian Crime Commission (O'Brien, (2008; 2010) highlighted the importance of separating the sexually abusive behaviours from the child in order that abusive siblings are given an opportunity to change their behaviours (see Box 1). This, however, must be balanced with the needs of the victim/survivor, and should not function to minimise their pain and suffering (O'Brien, 2010).

Table 1a: Developmentally based sexual behaviours - inappropriate, ages 0-18
Age groupDevelopmentally inappropriate sexual behaviours
0-5 Years of ageCuriosity about sexual behaviour becomes an obsessive preoccupation

Exploration becomes re-enactment of specific adult activity

Behaviour involves injury to self

Children's behaviour involves coercion, threats, secrecy, violence and aggression

6-10 Years of ageSexual penetration

Genital kissing

Oral copulation

Simulated intercourse

11-12 Years of ageAny sexual play which involves children younger than themselves.
13-18 Years of ageCompulsive masturbation

Attempt to touch or expose other's genitals - especially without permission

Sexual contact with animals and younger children

Using sexual themes to degrade others or themselves

Chronic preoccupation with sex and pornography

Table 1b: Developmentally based sexual behaviours - appropriate, ages 0-18
Age groupDevelopmentally appropriate sexual behaviours
0-5 Years of ageEngaging in exploratory touch

Looking at themselves and others

6-10 Years of agePlaying games as a form of sexual exploration (playing doctors)

Telling dirty jokes

Using dirty words

Showing interest in changes in their bodies

11 & 12 Years of agePeer related sexual activity

Sexual activity with same gender


Sources: Pratt et al. (2010); McVeigh (2003; p. 116); Araji (cited in O'Brien, 2008, p. 8).

Children who display problematic sexual behaviours towards their siblings may be acting out trauma as a result of having being sexually victimised themselves (Rayment-McHugh & Nisbet, 2003). When this is the case, "children and young people with sexualised behaviours confound understandings of ‘victim' and ‘offender' as mutually exclusive categories" (O'Brien, 2010, p. 5).

Certain family environments may have a negative effect on children that lead them to enact problematic sexual behaviours against their siblings. Exposure to pornography or other sexually explicit material can lead to children "copying" the behaviours they have seen. Similarly, permissive boundaries around sexual language and sexual behaviour may also have an effect (Hatch, 2005). Based on case studies of sibling sexual assault victims, one researcher stated that a patriarchal environment, which relies on traditional values, may create the context for sibling sexual abuse (Ballantine, 2012).

The terminology used to describe the behaviours of children who sexually transgress against their peers or family members is a difficult but important consideration. In order for the child who displays problematic sexual behaviours to separate the abusive act from who they are, it is important to use language that separates the abusive behaviour from the child. For example, terms such as "perpetrator" and "offender" label the child. Conversely, using terms such as "abusive behaviour" or "child who displays problematic sexual behaviour" lessens the stigma and offers potential to change the behaviour (O'Brien, 2010).

Availability and duration

Although duration of abuse is not strictly a definitional aspect of sibling sexual abuse, studies have indicated that duration is a feature because siblings live together and the abusing sibling has access to their victim (Hatch, 2005). Hatch pointed out that the close proximity of siblings also marks sibling sexual abuse possibly as an opportunistic crime - indicating that there is little difference between those who abuse siblings and non-siblings except for sibling availability (Welfare, 2008).

Women's Health Statewide (2005) conducted a study of 18 women who had been abused by their brothers and found that the longest period of abuse lasted 10 years, and the least for 1 year. The average abuse period was 5 years. Welfare (2010) found in her sample of 17 women abused by their siblings at different ages, but predominantly early adolescence, that the average length of time abused was 4.76 years and that the abuse ceased around the time the abused sibling reached adolescence.

In one study that included 41 victim/survivors of sibling sexual abuse, the average duration of abuse was 6 years (Carlson et al., 2006). The abuse ceased when:

  • the victim left home (10%);
  • the child with problematic sexual behaviour left home (25%);
  • the child with problematic sexual behaviour either started a romantic relationship (with a non-family member) or began abusing someone else (10%);
  • the abuse ceased for unknown reasons (30%);
  • the abuse ceased because it was discovered (7.5%); and
  • it was unknown why the abuse ceased (17.5%).

Intellectual and physical disability

Children with a physical disability are more vulnerable to abuse than able-bodied children (Higgins, 2010). Sexual abuse may also occur if one child is not aware (or does not have the ability to be aware) that another child is receiving sexual gratification from an interaction (Pratt et al., 2010).


Although there are studies that define sibling sexual abuse as possibly occurring between brother and sister, sister and sister, or brother and brother, the most common type of sibling sexual abuse occurs between a brother and a sister, with the brother as the abusing sibling (Carlson et al., 2006; Welfare, 2008). This is followed by brother and brother sexual abuse (Krienert & Walsh, 2011).

Most studies do not explore same-sex sibling sexual abuse in any great detail (Krienert & Walsh, 2011). Research into child sexual abuse and adult sexual assault attest to there being specific cultural and gendered barriers for male victim/survivors to disclosing abuse of any kind (Foster, 2011).

3 Sibling connotes biological, half and adopted siblings.

Prevalence and incidence

Prevalence and incidence

Very little is known about the prevalence of sibling sexual abuse (Caffaro & Conn-Caffaro, 2005; Carlson et al., 2006). Cases that come to the attention of the authorities may also not be typical of the types of abuses occurring but it is difficult to know for sure. This is because the cases that are known may be the extreme or more violent cases that families cannot ignore or deny and therefore are reported and/or documented. Additionally, national surveys such as the Personal Safety Survey (by the Australian Bureau of Statistics) do not include siblings as a category for intra-familial sexual abuse - or siblings are incorporated under the heading "family member" and therefore not separately identifiable.

The studies that do present prevalence data put sibling sexual abuse as more common than other forms of intra-familial sexual abuse (Monahan, 2010; Pratt et al., 2010; Rowntree, 2007; Thompson, 2009). Caffaro and Conn-Caffaro (2005) estimated that sibling sexual abuse occurred "three to five times as often as the most frequently cited form" (p. 609), father to daughter child abuse.

In a study of 51 children who had been sexually abused, about half reported being abused by a sibling (Shaw, Lewis, Loeb, Rosado, & Rodriguez, 2000). A study by the National Society for the Prevention of Cruelty to Children (UK) interviewed 2,869 young people between 18-24. The researchers found that of those who had been abused as children, 43% were victims of sibling sexual abuse (McVeigh, 2003). Further research is important to ascertain a clearer picture of prevalence in order to create awareness.

One US empirical analysis of offender, victim and event characteristics from national police records (Krienert & Walsh, 2011) revealed that of 13,013 incidents of sibling sexual abuse reported to police between 2000 and 2007, that:

  • 82% of victims were under 13;
  • 71% of the incidents involved female victims;
  • 13% of the sample involved multiple victims;
  • males accounted for 92% of sibling sexual abuse offenders;
  • 95% of offenders were older than their victims;
  • the average age gap was 5.5 years;
  • the most common dyadic relationship was male abusive sibling and female victim; and
  • one-quarter of the sample was male-male sibling sexual abuse.


Impacts for victim/survivors of sibling sexual abuse

Historically, sibling sexual abuse, when discovered, was considered natural sexual experimentation between siblings and treated as benign and without impacts (Welfare, 2008). However, the impacts of sibling sexual abuse are similar to other forms of child sexual abuse. Trauma is evident in victim/survivors of sibling sexual abuse. Impacts can be predicated on the type of response the victim receives from family members and/or therapeutic agents after disclosure (Rowntree, 2007; Thompson, 2009; Women's Health Statewide, 2005). Issues of disclosure will be discussed later in the summary.

Sexual abuse victims of any kind often display trauma symptoms such as intrusion, hyper-arousal and disassociation4 (Boyd, 2011; Herman, 1994). A study by Ullman (2007) quantified the effects of a negative response to disclosure of sexual abuse and found that those who received a negative reaction to disclosure had higher rates of and more post-traumatic stress disorder symptoms than those who received a more positive and validating response (Welfare, 2010).

Other symptoms of sibling sexual abuse victimisation may include mental health and adjustment issues well into adulthood - such as depression (McVeigh, 2003), lowered self-esteem (Hatch & Hayman-White, 2001), and affective disorders (Welfare, 2008). Long-term effects of sibling sexual abuse also include drug misuse (Crisma, Bascelli, Paci, & Romito, 2004), revictimisation, sexual dysfunction in adulthood (Carlson, 2011; Carlson et al., 2006; Pratt et al., 2010; Welfare, 2008; Women's Health Statewide, 2005), and parenting issues (Price-Robertson, in press; Tarczon, 2012).

The close nature of the relationship between siblings often exacerbates the impacts for victims. Other impacts may also be evident, such as guilt, humiliation (Thompson, 2009) and shame (Ballantine, 2012). These impacts mirror the experiences of victim/survivors who have been sexually assaulted by other family members and intimate partners (Wall, 2012).

There are also interpersonal difficulties. It has been hypothesised that being abused by a sibling may impact on the victim/survivors ability to relate to their peers and other family members in later life - including lower rates of marriage for victim/survivor's (Welfare, 2008). There is also a correlation between sibling sexual abuse victimisation and greater difficulty in maintaining love/sex relationships. These interpersonal impacts appear to be idiosyncratic to sibling sexual abuse as found by three studies - Russell (1986), Doyle (1996), and Caffaro and Conn-Caffaro (2005) - who attributed the problems to the minimisation of sibling sexual abuse by the abusing sibling, family members and professionals (Welfare, 2008).

Impacts for families

The impacts of sibling sexual abuse for families can relate to whether treatment is sought. Often even seeking treatment cannot mitigate the breaking up of family relationships (Kambouridis, 2012). This echoes work by Doyle (1996) who found that victim/survivors of sibling sexual abuse were less likely to have maintained a relationship with their parents than those who had experienced intergenerational sexual assault (Welfare, 2010).

The shame associated with perpetrating abuse against a sibling, the trauma and pain of being sexually abused by a sibling and the grief associated with having an abusive and abused child/ren in the family and can often mean the end of some family relationships. A family's response to a disclosure of sibling sexual abuse is often a result of the confronting nature of the abuse.

4 Intrusion: when unwanted memories of the abuse intrude on every day life. Hyper-arousal: severe surprise reaction to "ordinary" stimuli. Disassociation: a feeling of being disassociated from reality (Herman, 1994).



Many children who are victims of sibling sexual abuse do not report or disclose the abuse at the time it is occurring (Hatch & Hayman-White, 2001; Welfare, 2010). Due to the hidden nature and secrecy of sibling sexual abuse, the responsibility to end the abuse via self-disclosure falls upon the victim (Paine & Hansen, 2002). Another factor that exacerbates the lack of reporting is how parents and/or guardians respond to sibling sexual abuse disclosures. Often the abuse is minimised or denied because there is shame associated with sibling sexual abuse, or because there is a belief that the abuse is just normal sexual exploration (Krienert & Walsh, 2011). Some of the barriers to disclosure are outlined below.

Barriers to childhood disclosures of sibling sexual abuse


Much is made in the literature concerning sibling sexual abuse, of the taboo nature of incest and the confused messages received throughout history via literature and popular culture (Rayment & Owen, 1999). Representations of sibling incest throughout the ages have supported a cultural narrative of natural sexual experimentation and titillation based on the hidden and taboo nature of incest. An equal and balancing narrative of the destructive, exploitative and violent nature of sibling sexual abuse has not found a primary position in sexual assault messages, the media or popular culture.

If and when a disclosure does take place, or a parent or guardian discovers sexual activity between siblings, it is often dismissed as inappropriate play and perhaps swept under the rug, not discussed, or is denied (Rowntree, 2007; Welfare, 2010).


Another barrier to disclosure depends on the child's relationship within the family. Children may be cognisant of the hurt and embarrassment that a disclosure may produce. Concern over protecting the feelings of parents from the offending siblings actions creates a significant barrier for abused children (Caffaro & Conn-Caffaro, 2005).

Conversely, the lack of a positive relationship with parents may precipitate sibling sexual violence (Hatch, 2005). Therefore an inability to disclose to a parental figure may be due to lack of "emotional closeness and affection" in that relationship (Hatch, 2005, p. 64). Further to this, a fear of not being believed or of being blamed is highlighted in the literature (Crisma et al., 2004). Additionally children may fear authority - either parental or professional and be uncertain of the response and consequences of disclosure (Crisma et al., 2004).

Concern for the abusive sibling

One of the concerns for victims of sibling sexual assault in disclosing is the ambivalence they may feel toward having their sibling reprimanded. Many abused siblings remain silent because they love their abusive sibling and are concerned that if they tell, they will create trouble for their sibling. One example features in Welfare's (2010) work and describes a victim's reluctance to disclose due to fears that her brother would be banished or the police would become involved (p.109). Although victim/survivors are likely to be frightened of the abuse, a desire not to rock the boat may become a barrier to help-seeking.

Threatened by the abusive sibling

The abusive sibling may threaten their victim with retribution through violence or by implying the victim was complicit. Often the shame and guilt is enough to keep the abused sibling quiet (Caffaro & Conn-Caffaro, 2005). However additional threats from the abusive sibling add to this silencing. As the abusive and abused siblings live in the same environment, threats would be experienced as pervasive in every day life.

Finkelhor (1980) stated that none of the victim/survivors of sibling sexual abuse by an older sibling in his study had confided in anyone. The requirement to remain quiet is often an additional source of pain for the victims (McVeigh, 2003).

Confused emotions over abuse

Finally, confused emotions can create a barrier to disclosure. The abuse may be non-penetrative and may be experienced as having a nurturing element for the abused sibling (Monahan, 2010). This nurturing element may be experienced as a feeling of intimacy, closeness and feeling special, or being worthy of attention. This is part of the dynamic of many types of child sexual abuse and is why a victim may appear compliant and why there may not be evidence of violence.

The abuse may also cause feelings of uncertainty. Some victims of sibling sexual abuse are not willing or able to identify what has happened to them as sexually coercive - at least sometimes until adulthood (Lievore, 2003; O'Brien, 1991). One participant in a study of 41 young people who had been sexually abused was uncertain that what his brother had done constituted abuse "since the brother always pretended nothing happened" (Crisma et al., 2004, p. 1040).

Children who do not receive what they consider to be enough caring affection from parents, may welcome some facets of the attention of their abusive sibling, and this may create conflict over whether a disclosure is appropriate. Herman (1994) discussed the creation of compliant child victims by adult perpetrators who use threats and control in adult/child sexual abuse. Although peer sexual abuse or sibling sexual abuse is a different type of dynamic, there may be elements of creating a compliant victim by the very nature that siblings live together, through fear of disclosure by the abusive sibling implicating the victim in the abuse, and the victims own fears of their compliance in the abuse (Herman, 1994).

One such example comes from a case study with a woman named Marie, who did not disclose sibling sexual abuse until her adult years, and still felt complicit in the abuse. Marie felt this way even after therapy had helped her identify that her family had emotionally neglected her. She lived in fear of and uncertainty regarding her "participatory role in the sexual behaviours with her brother" (Ballantine, 2012, p. 59).

The following section explores the legal implications in consent and criminal responsibility as it relates to sibling sexual abuse.

Implications for therapeutic interventions

Implications for therapeutic interventions

As stated earlier in the review, originally sibling sexual abuse victims were treated and counselled but those children with problematic sexual behaviours were not (Welfare, 2008). This model of service delivery meant that children with problematic sexual behaviours were removed from families to ensure that the abuse ceased, and for the safety and recovery of the victim (Kambouridis & Flanagan, 2003). Although the safety and recovery of the victim is vitally important, treating the child with problematic sexual behaviour, and the family, is now also considered vital as the treatment of problematic sexual behaviour can stop the abuse from continuing and/or becoming more violent, as well as stopping a possible cycle of behaviour that can continue into adulthood (O'Brien, 2010).

The following section will outline the literature on therapeutic interventions for victim/survivors, children with problematic sexual behaviours and for the family who have been affected by sibling sexual abuse.

Abused siblings

Therapy can be an important component in healing. If trauma is not dealt with it can remain and manifest in a variety of ways, including drug and alcohol abuse, mental health issues and lack of social connection (see Boyd, 2011 & Living Well, 2012). A study by Monahan (2010) considered how trauma was revisited in adult victim/survivors when they were thrown together with their abuser in the event of ageing parents who required family assistance or had passed away and siblings were forced to work together to make arrangements.

Welfare's (2010) study with 17 women who experienced abuse at the hands of their brothers indicated that those who were given the opportunity to disclose to their parents and found support with their parents were less burdened with symptoms of post-traumatic stress disorder. However three sisters were not given the opportunity or had the opportunity closed off by parents who did not want to hear about the abuse. The silencing of these women had a "substantial impact upon the continuation of their severe symptoms and progress in recovery" (Welfare, 2010, p. 135).

The implications from the limited research indicate that sibling sexual abuse can have far reaching consequences for all parties and the appropriate provision of therapeutic intervention upon discovery of the abuse is an important area for further research (Monahan, 2010); as is the importance of parental support upon disclosure (Welfare, 2008).

Child displaying problematic sexual behaviours towards sibling/s

There is a consideration in the literature that the child who abuses their sibling/s may have some mental pathologies, a history of behavioural disorders and/or a history of being abused themselves. Family dysfunction is also thought to create the context for sibling abuse. A number of practitioners writing in this area now recognise the importance of the abusive sibling having access to therapy that is based on theories and treatments for children with problematic sexual behaviours (Hatch, 2005; Hatch & Hayman-White, 2001; Pratt et al., 2010; Welfare, 2010).

Statistics indicate that if children with problematic sexual behaviours are treated early, they have a chance to break the cycle of abuse that may have begun when they were abused themselves (Pratt et al., 2010). It is important to note that the "majority of boys who are sexually abused do not go on to commit abuse"9 (LivingWell, 2012, para. 1). However it is also true that detected adult offenders often have a history of perpetration going back to childhood, or more likely, adolescence (Boyd, 2006). Therapeutic intervention is vital in order to address the behavioural and psychological issues behind the abuse of a sibling. For girls who are abused in their childhood, they are more likely to continue to be victims of sexual and physical violence into adulthood, rather than perpetrators. However there is evidence to suggest that when girls are exposed to abuse in childhood, if they do go on to perpetrate abuse, it is more likely to be in the form of emotional and physical neglect of their own children (Tarczon, 2012).

Treatment and counselling can be a way to uncover past victimisation and deal with the trauma this has caused. This can be difficult terrain however, as there may be harmful psychological consequences because of their dual-identity as both victim and as the abusing sibling (Caffaro & Conn-Caffaro, 2005). The area of dual-identity is fraught for clients (children or adult) and for the therapists and indeed the institutions that treat them (Stathopoulos, forthcoming).

Based on her study of 17 female victim/survivors of sibling sexual abuse, Welfare (2010) found that the abusive sibling may develop cognitive distortions and may often differ to the abused sibling in their account of how the abuse developed, the extent of the abuse and whom they believe is responsible for the abuse. It is noted that it can be very difficult for the child who has displayed problematic sexual behaviours to face the responsibility of what they have done (Kambouridis, 2012; Welfare, 2010).


The literature suggests incorporating the family unit into therapy as much as possible for the purpose of recovery (Welfare, 2010). This is based on practice evidence that shows that the best outcomes for all involved (recovery for the victim/survivor and desistance for the abusing sibling) include attempts at building strong relationships within the family. Further to this, the greatest outcomes witnessed by researchers in the field involve the parents of the children finding a way to support both the abusive child and his/her abused sibling (Welfare, 2010).

From research of case studies of sibling sexual abuse, it was found that families in which sibling sexual abuse has been perpetrated often display blurred boundaries between members of the family as well as role confusion (Ballantine, 2012). Role confusion relates to parental and child roles, and a confusion (deliberate or otherwise) about who sets boundaries and who is in charge. Caffaro (2008) suggested that the therapist form therapeutic alliances with each family member as well as hold family group sessions (if possible and safe) in order to observe the family dynamic. This is why it is important to treat and counsel all/other family members. In the past, merely removing the child with problematic sexual behaviour and treating the victim actually engendered fractured loyalties and created tensions in the family unit (Kambouridis, 2012). The reactions and responses to the victim/survivor and child with problematic sexual behaviour by other family members can have a lasting impact and other family members may need guidance and support in order to meet the needs of their children during such a difficult time (Kambouridis & Flanagan, 2003). A "parental alliance is essential in developing family rules" which support the cessation of sibling sexual abuse (Caffaro, 2008, p. 9). However Caffaro goes on to add that eventually, intervention must focus on treating the affected family as a unit and this is echoed by other clinical researchers (Ballantine, 2012; Welfare, 2010).

Welfare's (2010) thesis on understanding the experiences of all members of a family affected by sibling sexual abuse is an important step in creating treatment options in this area. Siblings who have not been abused are affected by disclosures that may require therapeutic intervention. They are often caught in the middle, may be asked to take sides and/or want to maintain an image of their family as intact (Welfare, 2010). Support is advocated as the non-abused sibling/s make their way through the emotional turmoil that sibling sexual abuse may cause them.

Welfare (2010) also found that a mother's reaction to a disclosure of sibling sexual abuse is very important to the recovery of both the victim/survivor and the child with problematic sexual behaviour. As all members of a family require counselling, a multidisciplinary approach is advised (Caffaro & Conn-Caffaro, 2005). Caffaro and Conn-Caffaro (2005) suggested that integrated assessments and treatment responses are best practice to deal with what is a complex and challenging set of needs for each member of affected families.

9 For a more indepth discussion, please see: Addressing the Victim to Offender Cycle <>.



Sibling sexual abuse is an under-reported and hidden crime. Due to this, prevalence rates are not clear, however research indicates that it is three to five times more prevalent than intergenerational sexual abuse. Sibling sexual abuse has historically been ignored, minimised or denied by parents, professionals and authorities as benign childhood sexual experimentation. Current literature however, suggests that the impacts for abused siblings are far-reaching and long-term due to disclosures not occurring frequently in childhood.

Therapeutic interventions require the recognition and validation of sibling sexual abuse. Abused siblings, abusive siblings and other family members require thoughtful and holistic responses from professionals to deal with the specific needs resulting from sibling sexual abuse. In order to better understand prevalence, to reduce barriers to disclosure, and to provide therapeutic responses that address the issues and needs of all family members and facilitate recovery, further research is required.



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Mary Stathopoulos was a Senior Research Officer at the Australian Centre for the Study of Sexual Assault.

The author would like to thank AIFS staff, particularly Antonia Quadara, Cindy Tarczon and Daryl Higgins for their guidance and feedback through out the production of this publication.


Stathopoulos, M. (2012). Sibling sexual abuse (ACSSA Research Summary). Melbourne: Australian Centre for the Study of Sexual Assault, Australian Institute of Family Studies.



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