Sibling sexual abuse: a form of family dysfunction as opposed to individualised behaviour

ABSTRACT This paper presents a reconsideration and more in-depth discussion part of some the findings of the Home Office funded Sibling Sexual Abuse (SSA) project (King-Hill et al, 2023). The focus of the paper on the role of family systems, especially dysfunctional family systems, in the sexual abuse. The research is based on 17 semi-structured interviews with survivors of SSA (n=17 female), which were thematically analysed. This resulted in the research team being able to identify 10 commonly identified markers of SSA and family dysfunction. The 10 markers highlight that the family structure, systems, processes, and functionality all contribute to the conditions that enable Sibling Sexual Abuse to occur. The paper goes on to discuss the importance of understanding family systems, ACE's, and trauma in preventing and responding to Sibling Sexual Abuse. The paper concludes that the family system is a key player in Sibling Sexual Abuse and needs to be considered in prevention and treatment as the child who id harmed and the child that harms. PRACTICE IMPACT STATEMENT The impact of this paper is both clinical and professional. It provides insights into the role of family systems in sibling sexual abuse cases and by result feeds into discussions around the effective prevention of and response to this form of sexual abuse.


Introduction
Recently there has been heightened research (Bertele & Talmon, 2021;King-Hill et al., 2021;McCoy et al., 2022;Tener et al., 2020), and practice (Yates & Allardyce, 2021, 2022) interest in the field of Sibling Sexual Abuse (SSA).However, SSA is not a new phenomenon or social issue (Finkelhor, 1980).The issue of sexual abuse within family systems has been discussed and examined for decades, but the focus up until recently has been on parent-child sexual abuse (Herman, 1981;Lawson, 1993;Masilo, 2018).Due to this, the literature on SSA is limited, especially in terms of empirical research (see Bertele & Talmon, 2021).Current research on SSA does indicate a link between family systems, trauma, and sexual abuse (GIG Cymru and NHS Wales, 2015;Joint Target Area Inspections report, 2020;Levenson et al., 2014;Levenson & Grady, 2016;McCartan, 2020McCartan, , 2022;;McCartan et al., 2021;Scottish Children and Families Directorate, 2018;Tener et al., 2018;Tener et al., 2020), but this has not been formally researched or discussed in respect to SSA.Currently, in sexual abuse policy, practice, and research there is a focus on the role of adverse experiences and trauma in offending behaviour (HMI Probation, 2022;Kemshall & McCartan, 2022;Levenson & Grady, 2016;McCartan, 2020McCartan, , 2022)).This signals a reengagement with, and the importance of, developmental, life-course criminology in preventing as well as responding to offending behaviour (Laub & Sampson, 2020), and its links to the bio-psycho-social approach to risk assessment and management (Walton et al., 2017).
Research into dysfunctional and abusive families highlights the potentially traumatising nature of these family systems on child development and social inclusion (Alink, Cyr, & Madigan, 2019;Beckerman et al., 2018;de Maat et al., 2021).Research on young people (Dopp et al., 2020;McCuish & Lussier, 2018) and adults (Blokland, 2018;Luisser & McCuish, 2020) who sexually harm has indicated a number of traumatic risk factors, or Adverse Childhood Experiences (ACEs) in the family histories that have contributed to their sexually abusive behaviours (Grady et al., 2016;Kahn et al., 2020).These reflect the general criminogenic literature which shows that people who have ACEs (i.e.family dysfunction, drug-addicted parents, emotional abuse, sexual abuse, and trauma in childhood are more likely to be more criminogenic and have poorer life outcomes compared to those who do not) (HMI Probation, 2022;McCartan, 2020).It is important to note that we are not saying that ACEs and childhood trauma result in anti-social and problematic behaviour, but rather the impact of these factors is amplified or mitigated by the family environment, and this can lead to problematic behaviour (McCartan, 2020(McCartan, , 2022)).Therefore, the family environment and context are essential in understanding all forms of anti-social behaviour, but especially in cases of SSA where the family environment is a key factor in the abusive behaviour and key in enabling access to the victim.
The research outlined in this paper is an exploratory piece based on empirical research with survivors of SSA which examines the role of the family, and the impact of the family, in their sexual abuse (King-hill et al, 2023).This is important in understanding SSA because the family is such a central element to the abusive behaviour, its causes, and consequences.This special edition of the Journal of Sexual Aggression has articles with extensive literature reviews on SSA, and therefore are not replicated in this paper.This paper is a discussion piece focusing on the family system in the context of SSA based on data collected as part of a larger, funded study (King-Hill et al, 2023).

Design
Empirical research in SSA is relatively underdeveloped with respect to other areas of sexual abuse, which means an in-depth understanding of the issue requires development (or lived experience).The most effective way of doing this is through qualitative research (Holloway & Wheeler, 2013;McCartan, 2023;Robson & McCartan, 2016).Semi-structured interviews allow participants to provide rich and detailed data on a sensitive subject with the flexibility of researchers being able to probe and ask unplanned questions (Braun & Clarke, 2006).Given this the research team interviewed 18 SSA survivors (17 female and one male) all over 18 years old.The sample was obtained through opportunity and snowball sampling (Bryman, 2016;Flick, 2009).An external link agency provided the project team with potential participants who were screened for suitability.During analysis, the team decided to remove participant 18 as they were the only male in the sample.The rationale for this decision was that their experiences and understanding of SSA may have been shaped differently by their gender and could lead to skewed conclusions when included alongside the other 17 female participants.The authors would like to highlight that this does not discount the experiences of male survivors of SSA and would strongly advocate for research focused specifically on male survivors (see Table 1 for final sample).

Procedure
The original research took place during the COVID-19 national lockdowns in 2020 and therefore the researchers were not able to conduct the semi-structured interviews face-to-face as originally planned (Dodds & Hess, 2021;Lobe et al., 2020).The research took place remotely via Microsoft Teams, with participants being offered a range of scenarios which included interviews via computer with both screens on, with their screen off and the interviewer's screen off, with the interviewer's screen off and their screen on, or with both screen on (Sipes et al., 2022).Participants were also offered the opportunity to be interviewed with one call lasting approximately 45-60 min or several smaller interview opportunities (three calls of 20 min), depending on which suited their situation best.The researcher went through the information sheet, privacy details, the consent sheet and explained that a series of questions would be asked surrounding SSA.Participants were asked whether they gave consent at the start of the interview as well as written consent via email prior to the interview (due to COVID−19 restrictions on in-person meetings).All interviews were recorded, then later transcribed on Otter.ai and coded in NVivo.

Materials
The semi-structured interview schedules for survivors and professionals were broadly comparable and developed from the pre-existing literature and the experience of the research team (i.e. in developing, conducting, and analysing qualitative research as well as experience of research and practice in the field of psychology, sexual abuse, and working with survivors), in conjunction with the research project advisory board.The semi-structured interview schedule focussed on understanding the lived reality of disclosing, seeking support, coping with, and the impact of SSA (see Appendix 1).

Ethics
When undertaking sensitive research ethical considerations are paramount.The research received approval from the UWE research ethics committee (reference number HAS.21.01.076) as well as receiving approval from Rape Crisis England and Wales and the project's research advisory panel.In developing the research, the team took into consideration ethical guidelines from the British Psychological Society (Oates, 2021), the British Society of Criminology (2015), and the National Organization for the Treatment of Abuse (2022).The research paid particular attention to participant wellbeing, safeguarding, and confidentiality to make sure that they were not revictimised compromised, or traumatised by the research.All participants were offered a wellbeing follow up post-interview support provided by a local rape crisis/support organisation with a qualified counsellor.All data was stored on a password-protected UWE OneDrive folder only accessible to researchers in compliance with the UWE data storage policy.To enhance the trustworthiness of analysis and credibility checks, researchers utilised weekly group supervision with the lead investigator to provide a range of perspectives.

Thematic analysis
Using an inductive approach, whereby analysis is not shaped by theory, the data were analysed using thematic analysis (please see Braun & Clarke, 2022, for a more detailed explanation of thematic analysis) to create a set of themes to reflect the data.The process of thematic analysis involved familiarisation with the data by reading and rereading the verbatim transcribed interviews, coding by picking out key points relevant to SSA with a latent approach that captured underlying ideas, patterns, and assumptions, generating themes after a discussion with the research team and subsequently creating a thematic map (see Figure 1), reviewing those themes to ensure they fit with the research aims, defining and naming the themes and finally writing up the analysis.

Results
The thematic analysis identified several key markers (or identifiers) in SSA tied to family systems, practices, and dynamics.Whilst these markers of behaviour do not suggest a typology or set of formation criteria for casework, they do prove a useful starting point for considering how the family environment contributes to SSA.These are highlighted below: (  (6) Poor parental boundaries and inconsistent parenting (7) Denial of abuse and downplaying child's voice (8) Normalisation of dysfunction and acceptance of the abuse (9) Clarity brought about by distance and space from the family (10) No two SSA or family experiences are the same.
These commonly identified markers are discussed below, highlighting related research evidence; before drawing all themes together in the discussion.
(1) Abuse and dysfunction as central component of broader family systems All the participants talked about how there was often a broader context of abuse within the family system, whether that be in the immediate family (parents and siblings, the household) or the broader family (i.e uncles, aunts, and cousins; the extended family).This suggests that participants' experiences of SSA were symptomatic of broader anti-social or problematic family dynamics across the extended and social family, not just the nuclear family.Participants talked about a culture of misogyny, sexism, power, control, and a difference in the way that siblings of a different gender were treated and the complicit acceptance of this across the wider family system.The acceptance of sexism, misogyny, and abusive behaviour laid the groundwork for the acceptance of sexual abuse within these broad, and nuclear, family systems as an acceptance of it by family members and the survivors themselves as "normal" if not acceptable.
" … I think that there's quite a high occurrence of inappropriate relationships between older men and younger girls in Jamaican culture, which I think the culture kind of brushes under the carpet.And in me saying that, I think that there's the large majority of Jamaican people who are aware of it and think it's terrible … " (Participant 3) (2) Abuse and dysfunction being commonplace in the nuclear/immediate family Most participants, approximately 60% (10 out of the 17 participants), talked about how their parents had a very dysfunctional relationship, often including instances of emotional, psychological, and physical abuse.The participants reinforced that the broader family dysfunction and problematic attitudes and behaviours often played out in their parents' relationships and the functioning of the nuclear family.
" … the way that my father was treating my mother with the way he was treating me.And, you know, there was a lot of physical aggression happening in that household, but it was always a man.You know, abusing his physical power over a woman, yeah.meant that I just had it in my head, okay, this, you know, this is what being a woman is, you know, and I am that and I'm, you know, here to be, you know, be, you know, beaten up and sexually abused … " (Participant 14) (3) Dual status of sexually harmful children Further substantiating this culture of dysfunctionality in the broader family system and nuclear family, many participants also highlighted that the sibling who harmed them had experienced abuse from other family members.Arguably, this reinforces the cultural acceptability of abuse within the family system and the normalisation of such abuse.The participants talked about how the abuse that their sibling had suffered by other family members as having a direct impact on the harmful sexual behaviour enacted towards themselves.This highlights the impact of trauma and adversity in the lives of the young people who go on to enact SSA.
… my sister was the one who had molested me.And I think, clearly, something suddenly happened to her.I know it did.She's told me anyway … she did what she did to me because she was acting out what happened to her … " (Participant 3) Several of the participants (12 out of the 17) also highlighted that they were not the only sibling in the household being harmed by their sibling.They discussed how often the sibling carrying out the sexual abuse would do it to other siblings in the household which indicated an ongoing and pervasive pattern of abuse.As such, the abuse was not personally directed at the individual child who was harmed, but rather represented the exertion of power, control, and learnt problematic behaviours from the child who enacted harm.This further reinforced the ongoing family dysfunction and abusive environment experienced by many of the participants.
" … and I'd come home, and my brother was like, "I need to speak to you".I was like, "Okay", then.And he said, he said, "Danielle, is the reason I've had been having all these mental health problems and problems with drugs is because Danielle did all these things to me".And then in my realisation, I was like, "Yeah, me too".And then it was like a big discussion with my family about what happened … " (Participant 17) (4) Conflicted, paradoxical feelings towards the abusive sibling The recognition of the family dysfunction and that the sibling who harmed them was often being abused led to paradoxical feelings in the survivors of SSA across most of the sample (15 out of the 17 participants).They had sympathy for the sibling who enacted harm because of what happened to them, and they could see the causal impact, but they could not forgive them.There was a recognition that the abusive context within the family system had resulted in harmful sexual behaviour.
" … if my sister wasn't getting abused by my uncle, she wouldn't have interacted these games on me, too.She was just playing out what was happening to her with me … " (Participant 1) (5) Poor parental engagement and communication: absent/disengaged parents The vast majority of the participants talked of absent and disengaged parents and the impact that it had on the functionality of the family system.Many participants argued that parental absenteeism, in one form or another, laid the groundwork for, and enabled, the continuation of SSA.The participants talked about different forms of absentee parents, either through the death of a parent, one parent working away from home, the separation of parents and one leaving the family home, and the disengagement of parents from family life despite remaining in the family home.The participants stated that all these forms of parental absenteeism were highly impactful and reflected the wider climate of dysfunctionality in the family.Furthermore, they highlighted this gave a platform of power and control to the sibling who harmed them, who was often older and acting in a parental capacity.The additional responsibility placed on siblings whilst parents were unavailable often led to a power imbalance between siblings, in turn, bolstering the abusive dynamic.
" … I mean my parents very much put responsibility on my sister to kind of look after me.So, there was a definite power balance dynamic, which still exists, which is why I don't talk to her anymore.But that was very much.Kind of, yeah, there was no picking up on an inappropriate behaviour.Like my sister.She was very violent, very if you didn't do what she wanted.We're not getting that kind of like our sibling punch, like, yeah, it was more than that, like it was.And she's quite manipulative.very manipulative.Quite spiteful.But my parents never seemed to tell her not to be … " (Participant 10) Parental absence meant that the participants could not ask their parents for help or support, resulting in them not disclosing to anyone or seeking help.This also resulted in many of the participants feeling abandoned and not protected by their parents, feeding into issues of self-worth and a feeling that they would not be believed even if they disclosure.These poor boundaries around sex also played out in misogyny, sexism, and the difference in parental treatment of their sons versus their daughters.Participants discussed highly gendered familial attitudes, which reinforced the idea that sexualised behaviours and abuse were acceptable in the home, with daughters being more sexualised and boys not being challenged for their sexualised behaviours.Again, this fostered a problematic, dysfunctional family culture within which SSA was normalised.
" … I guess my brother was always hanging out with older relatives like cousins, uncles and he's got a father, and all of them were very misogynistic, so he was clearly learning quite early on that that he was the one in charge and that he was one who could do anything and have no consequences because he was a man.I also internalised this idea that because I was a woman I was too, you know I was the one to blame and I was the one that was the one who had to feel ashamed because of all the things that I was going through and that while maybe it was all my fault … " (Participant 7) (7) Denial of abuse and downplaying child's voice Upon recognising the abuse that they had suffered the participants often disclosed to their parents and family members, many of whom either did not believe them or want to engage with them on the issue (reported by 13 of the 17 participants).Often this was either because they did not want to disturb the status quo, they did not want to recognise that it was happening, or they were unable, or unwilling to process it, because of what was happening to them within the family contact.
"[my mother] she sort of said, well, you can't you know, you can't press charges against your own brother.You know, she said, you will, you know, all this stuff about how you're ruining this family and your sister will go into care.And, you know, do you want any of that to happen?… " (Participant 14) " … so, when I told my mum, she said that I was over exaggerating, that I was making something out of nothing, and I was lying.Yeah, it wasn't received very well, which I think is understandable to a certain extent.It's not very helpful … my mum probably is pushing it away; she just doesn't want to deal with it … " (Participant 10) " … I've disclosed it twice and he's [my father] still not there for me.And that that's been probably the single most hardest thing … says stuff like oh, but you're just kids.It's what kids do at night.I mean, and like just really, really minimising the behaviour … " (Participant 12) The aforementioned participants felt that the dysfunctional nature of their family system prevented and discouraged them from disclosing the SSA when they recognised that it was abuse, which had significant ongoing implications for them.Participants talked about the fact that they were not believed at home, and often dismissed meant that they did not feel that they could tell anyone, and therefore did not disclose appropriately at the time.
" … because of my parent's reaction, I always assumed people would think the way my parents thought, especially people of their age or their generation … " (Participant 10) (8) Normalisation of dysfunction and acceptance of the abuse The participants in discussing their family systems recognised that the inherently dysfunctional nature of their lives seemed normal, almost functional to them, as it was all that they knew.
" … I think I wasn't aware that I needed help.Yeah, because it was normalised.Yeah, to me in such a way that I just wasn't aware that I needed help.Which is why I think there was such an issue with behaviour and emotional dysregulation, because like I was just sort of all over the place and didn't know what I needed.But then on the on the same in the same breath there was, I do sort of vividly remember having conversations with my mom, where I did sort of, like ask her things and raise things to her.But unfortunately, my parents were both quiet, like physically abusive.So, it was sort of like a dysfunctional family dynamic … " (Participant 4) (9) Clarity brought about by distance and space from the family Participants reflected that it was not until they were older and had left the family environment, either as a teenager or an adult, that they recognised that their family system was dysfunctional and that the abuse that they suffered was not normal.
" … growing up, I thought it was normal.So, it's from quite a young age.Yeah, I didn't really understand that.I just kind of thought it happened to everybody.It wasn't until I was older.And really, like when I first had my first boyfriend, and started to learn about stuff like that, I realised that things like that weren't actually normal … " (Participant 13) (10) No two experiences of SSA are the same Despite most of the participants talking about the dysfunctional nature of their families and how this fed into the harmful sexual behaviour enacted by a sibling, it is important to note that not all participants reported this broader dysfunctionality.Some participants talked about their families as being normal and functional, with SSA being abnormal within the context of the family and the abuse being more related to issues with their sibling rather than the family system.
"so, from being born to being seven, or, eight, you know, there were lots of love and affection and a caring mom and dad and all those kind of things.So, I got all those primary needs when that development were really, really good.And then all of a sudden this started happening.And it would just like, I don't know, just weird.I don't really know how to explain it.So, I guess that's why and that's what stopped me from doing it because it will I Oh, no.It's all right for the day.And I don't want to break this happy, home kind of thing.Yeah.I don't want that on me.Yeah … " (Participant 12) Building upon this, not all the participants felt that their families where unresponsive to their disclosure, regardless of the families' issues or dysfunctionality, with some parents believing them and encouraging them to report them to go further.
" … my mum was fully supportive.And obviously she because she said to me, if you don't go to the police, I'm, I'm gonna go … " (Participant 12) " … Mum, she said, I want you to stop feeling this shame.It's not yours.And that was an amazing sentence for my mother to come out with.And it was very important … " (Participant 6) It is important to recognise this aspect as it reinforces the individualised nature of family systems and the complexity of sexual abuse.It is important then we look at the family system and consider the role that it has played in the abuse.

Discussion
The thematic analysis highlighted 10 key markers of SSA in family systems, suggesting that the participants felt that their family systems were dysfunctional with ACEs and trauma being common throughout them (HMI Probation, 2022;Joint Target Area Inspections report, 2020;McCartan, 2020).This appeared to result in a family environment and culture that was conducive to SSA.Whilst dysfunctional family systems do not cause SSA they can create conditions where this harmful behaviour is more likely to happen and more likely to be facilitated or ignored by others (Joint Target Area Inspections report, 2020).This research has highlighted that SSA is often rooted in adverse experiences and trauma (Felitti et al., 1998;Finkelhor et al., 2013) with both in terms of the family environment and the direct life experiences of the siblings.This also reflects research on adults convicted a criminal offence in general (GIG Cymru and NHS Wales, 2015;HMI Probation, 2022;Joint Target Area Inspections report, 2020;Scottish Children and Families Directorate, 2018) as well as those convicted of a sexual offence specifically (Levenson et al., 2014;Levenson & Grady, 2016;McCartan, 2020McCartan, , 2022)).The participants often talked about adverse experiences within the home (i.e.problematic parenting, domestic violence, mental health issues, etc) and that the siblings who enacted harm were also often survivors of abuse (i.e.sexual, physical, or emotional abuse) themselves, often at the hands of a family member (i.e. a parent or a close relative), which had a direct impact on the harmful sexual behaviour (Allardyce & Yates, 2009).Participants indicated that the behaviour that they suffered was often a reaction to a learned behaviour from their sibling regarding what was happening to them (Caffaro, 2020;Yates & Allardyce, 2021); which aligns with the literature on adults who sexually offend (Levenson et al., 2014;Levenson & Grady, 2016;McCartan, 2020McCartan, , 2022)).This meant that the participants often had paradoxical perceptions of their siblings and the harm that they suffered, with many of them stating that they could understand why their siblings did what they did but they could not forgive them or condone it (Yates & Allardyce, 2021).This is important as it speaks to the complexity of SSA and highlights the multitude of interlinked causal factors.In many ways SSA should be considered and treated similarly to child sexual exploitation, in that a young person who is engaging in SSA should be seen as a victim.Fundamentally, their anti-social and problematic behaviours are rooted in their adverse experiences and that needs to be considered in how we respond to and work with them (Children's Society, 2022; Independent Inquiry into Child Sexual abuse, 2020).However, it is pertinent to note that whilst the environmental factors and approaches reflect CSA, SSA is distinctly different, and this should be accounted for when any approaches and interventions ae considered.
Treating SSA cases as purely individual issues is problematic as the family system has directly, in most cases, contributed to the abusive behaviour.This means that the family needs to play a role in identifying and challenging the problematic attitudes, beliefs, and behaviours that led to the abuse to understand it, and prevent it from happening again (Tener et al., 2018); therefore a whole family approach is required (King-Hill et al., 2023).The family needs a therapeutic intervention as much as the two siblings involved in the abuse do and the level, scale, and impact of this intervention can, and will impact, recovery from the abuse.However, it is also important to remember that the whole family has been impacted by the SSA either directly (by being harmed or witnessing it) or indirectly (by being part of the dysfunctional family environment) and therefore needs to be considered in the response to the abuse.Thus, a family systems approach in responding to SSA is essential (Karakurt & Silver, 2014).
Hence, understanding and responding to SSA is as much about understanding the family system within which it manifests as well as the individual family member who has carried out the abuse.To prevent and respond to SSA we need to recognise the dysfunction within the socio-ecological context of the family and tackle the abusive behaviour at all four levels: individual (the victim or the person who has been harmed); interpersonal (the relationship between the victim and the perpetrator); the community (the nuclear/immediate family); and the society (the broader family system).By working across all four levels, understanding can be gained of the family dysfunction, its causes, the way that it manifests, and how to stop the problematic behaviours while holding all involved accountable.At each level, a different approach should be adopted depending on the individuals involved, and across the life of any intervention, the levels would be integrated to create a holistic, family systems model that tackles the root causes of the family dysfunction and the SSA.
This means that opportunities to prevent and the ways in which we respond to SSA need to be rooted within the family systems and contexts, with pro-social strengths-based interventions having the ability to create and reinforce functional family systems, understand dysfunctional systems, and therefore reduce the risk of SSA occurring (see Figure 2).
Understanding that the family system is as central to the perpetration of SSA, as the child who has harmed and the child who has been harmed, means recognising that SSA has three key enablers.It highlights that the family system should be treated like its own entity and it should be the focus of treatment and support as much as the children involved in SSA.

Conclusion
This paper demonstrates how the experiences of growing up in a dysfunctional environment can lead to acceptance of the problem and normalisation of abusive behaviour; highlighting the importance of family systems, adverse experiences, and trauma in the lives of people who enact sexual harm (Joint Target Area Inspections report, 2020; Levenson et al., 2014;Levenson & Grady, 2016;McCartan, 2022).This, therefore, may lay the foundations for maladaptive behaviours, attitudes, and coping strategies (Caffaro, 2020;Levenson & Grady, 2016;McCartan, 2020;Yates & Allardyce, 2021).The participants' dysfunctional family life became a contributing factor to the SSA because it normalised the abusive behaviour and in turn allowed the child who enacted harm to think that their behaviour was acceptable and the child being abused to think that they should not report it as everyone else experiences the same type of abuse (Yates & Allardyce, 2009).When considering Adverse Childhood Experiences (ACEs) (Felitti et al., 1998;Finkelhor et al., 2013;GIG Cymru and NHS Wales, 2015;Scottish Children and Families Directorate, 2018), it can be seen from the findings of this study that they played an integral part in participants'experiences of SSA.Early life experiences impact signiifcantly upon life trajectories and this requires consideration when approaching SSA.These are also strongly linked to abilities to form attachments, again an element that was present in the findings, and which is reinforced in research on people who commit sexual offences as adults (GIG Cymru and NHS Wales, 2015;Levenson et al., 2014;Levenson & Grady, 2016;McCartan, 2022;Scottish Children and Families Directorate, 2018); thereby reinforcing the importance of life-course, developmental pathways in understanding criminological behaviour (Laub & Sampson, 2020).To better understand how to best intervene with respect to SSA, both in a preventative and responsive capacity, professionals and practitioners need to better understand the lived reality of the family, its daily function, the role of adverse experiences within it, as well as how readily the SSA is accepted.This means that interventions need to focus as much on the relationship between family members and the family context, as the psychology of individuals involved, to provide a holistic and multi-level approach to addressing SSA.
1) Abuse and dysfunction as a central component of broader family systems (2) Abuse and dysfunction being commonplace in the nuclear/immediate family (3) Dual status of sexually harmful children (4) Conflicted, paradoxical feelings towards the abusive sibling (5) Poor parental engagement and communication: absent/disengaged parents

Figure 1 .
Figure 1.Sibling Sexual Abuse in the family socio-ecological system.

"
… mom died when I was nine from cancer.And my father, I've got two older brothers.And my brother.My dad couldn't really, I guess he chose to go to work a lot more than care for us children.And, yeah, so my next sibling up, he's six years older.And then the other one is eight years older.And yeah, it was a huge impact.I you know, I didn't I didn't know what was going on.I didn't know.It wasn't normal.I think, you know, I was a child.I just didn't really have an understanding until I sort of got to about 11 years old … " (Participant 9)

"
… she just wasn't there [the mother].I wish I had been able to say something because that would have made a big difference.I mean, who knows what would have gone on?But certainly at least there'd be eyes in the house, [and she'd know] more about what was going on between us.Maybe there would be more supervision or more checking in or maybe she wouldn't … " (Participant 6) (6) Poor parental boundaries and inconsistent parenting Some participants (9 out of the 17) talked about poor parental boundaries, with some of the clearest examples being around sex, sexuality, and pornography.Participants talked about parents viewing pornography in shared spaces in the home and engaging in sexually inappropriate behaviours around children, which reinforced the household dysfunction and normalised harmful sexual behaviour." … he (dad) would do weird stuff like he kind of like … like a shower with the bathroom door open and with the shower curtain open, so you could kind of see like, your dad, washing himself … my father would do things like watch pornography in the living room.Like when I was a kid … " (Participant 14)

Figure 2 .
Figure 2. Context mapping of sibling sexual abuse in the family system.
" … yeah.So, for me, it was just that oh, this is you know, I guess this is what happened, but he doesn't want me to tell mom or dad because I don't know at the time.You don't think that I do.But I guess it was.You know, I was worried about what happened.I knew it was wrong.But I was worried what happened to him because I still cared for him.He was my brother … " (Participant 8)