Journal of Applied Research in Intellectual Disabilities 2009, 22, 96–101
BRIEF REPORT
The Relationship Between Childhood Abuse, Psychological Symptoms and Subsequent Sex Offending Susan Hayes Centre for Behavioural Sciences, Discipline of Medicine, Central Clinical School, University of Sydney, Sydney, NSW, Australia
Accepted for publication
29 September 2008
Background Childhood sexual and physical abuse has been related to subsequent offending behaviour in nondisabled individuals as well as people with intellectual disabilities, but there is a dearth of research examining the link between these two characteristics and psychological, behavioural and psychiatric symptoms amongst sex offenders with intellectual disabilities. The aim of this study was to examine the relationship between childhood abuse, history of psychological and psychiatric symptoms, and patterns of violence in later offending. Methods Twenty sex offenders with intellectual disabilities were compared with 20 non-disabled sex offenders. The Kaufman Brief Intelligence Test, the Vineland Adaptive Behavior Scales, and a structured clinical interview were administered to participants. Results Offenders with ID were more likely to report that they had been the victim of physical abuse during childhood; aggressive behaviour during adulthood was related to a history of having been the victim of child-
Introduction Research on sex offending amongst people with intellectual disabilities (ID) demonstrates the importance of background and psychological factors including weak family ties and support, history of substance abuse in the family, and deficits in adaptive behaviour, especially communication skills (Thompson & Brown 1997; Firth et al. 2001; Hayes 2002; Lindsay 2002). Sexual offending in this group is related to sexual deviancy, more so than impulsiveness (Parry & Lindsay 2003), although difficulty controlling aggressive and other non-sexual impulses remains a contributing factor for some perpe-
hood physical abuse, or exposure to family violence. Participants in the ID group were more likely to be diagnosed with depression, post-traumatic stress disorder and aggressive behaviour. A history of childhood exposure to violence was related to the development of later symptoms, for both ID and non-disabled offenders. Perpetrators with ID who had been physically abused during their developmental years were significantly more likely to threaten or use violence during the offence. Conclusions The study suggests that childhood abuse may be related to severity of the crime, and to the development of later psychological and psychiatric symptoms. Longitudinal research in this area and a larger sample size are needed to clarify and extend the present findings. Keywords: child abuse, intellectual disability, mental disorder, sex offending
trators with ID (Firth et al. 2001), as does opportunity (McCarthy & Thompson 1997). High levels of prior sexual and physical abuse in all offender groups, sexual and non-sexual offenders, as well as ID and non-disabled offenders are reported (Thompson 1997; McElroy et al. 1999; Balogh et al. 2001; Lindsay et al. 2001; Hayes 2002). The relationship between having been the victim of abuse and later offending behaviour is more often explored in research on non-disabled populations; for example, adolescents who demonstrate high levels of violence are more likely to have been exposed to frequent violence at school, in the neighbourhood or at home, and to report more
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psychiatric symptoms, higher levels of depression and more problems with self-esteem (Lai 1999). Lindsay et al. (2001), in a study of 46 sexual offenders with ID and 48 non-sexual offenders, show that a significantly higher proportion of the sex offenders report having been sexually abused in childhood (38% versus 12.7%), whilst the non-sexual offenders were significantly more likely to have been the victim of physical abuse in childhood (13% of sex offenders versus 33% of non-sex offenders). The authors concluded that childhood sexual abuse may be a significant variable in the development of sexual offending tendencies in adulthood, although agreeing with Finkelhor (1984) that to suggest this is the only variable relevant to the ‘cycle of abuse’ is simplistic. Research concerning psychiatric symptoms amongst sex offenders with ID (Lindsay & Lees 2003) indicates that sex offenders report less anxiety and depression than the control participants. Lunsky (2003) states that people with ID with high depression scores are lonelier and have higher stress levels than comparison participants who report being less depressed. Gender differences emerge, because not only are women with ID more likely to be depressed than men, but those who score highly on depression report more prior abuse, poor social support from family, and unemployment. Depression is related to low self-esteem, poor perceptions of social attractiveness and low group belongingness (Dagnan & Sandhu 1999). This study investigates abuse history and psychological, psychiatric and behavioural symptoms among a group of sex offenders with ID, comparing this group with non-disabled offenders who have committed sexual offences. The aim of the study is to determine whether sex offenders with ID display symptoms and abuse characteristics which distinguish them from their nondisabled counterparts.
Method Participants Participants in the study were drawn from a clinical forensic group of male offenders who were referred for assessment to a community forensic psychology clinic because of their offending behaviour. The participants were referred by their legal counsel on the basis that they had committed an offence. The sample was not randomly selected from a population of offenders and was a sample of convenience. The participants gave informed consent for their information to be included
anonymously in data collection. Within this group, 20 were sex offenders with ID and 20 were non-disabled sex offenders. The IQ cut-off score for ID was 70. The mean age was 35 (range 18–52 years); no significant differences were noted between the ID and non-ID groups. All stated that they were heterosexual. There were no indigenous participants. The group with ID obtained a mean score on the Kaufman Brief Intelligence Test of 55, and on the Vineland Adaptive Behavior Scales of 50, whereas the comparable mean scores for the non-ID group were 85 and 77.
Measures and procedure The participants were assessed using the Kaufman Brief Intelligence Test (K-BIT; Kaufman & Kaufman 1990) and the Vineland Adaptive Behavior Scales (Sparrow et al. 1984). They also participated in a structured clinical interview, administered by an experienced clinical psychologist, encompassing areas such as background and family characteristics, prior abuse, and current and previous psychological ⁄ psychiatric disorders as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (American Psychiatric Association 2000). Information about the alleged offence(s) was obtained from police facts sheets and other legal documents, as well as from the participants. Sexual and physical abuse in childhood was defined according to Lindsay et al.’s (2001) parameters, that is, as contact of a sexual nature, including activities involving non-body contact (exhibitionism), and body contact such as sexual touching, vaginal, oral, and anal sex. Physical abuse was defined as being struck in any area of the body, being thrown, pushed or forced against an object, or being struck excessively on the buttocks. There was no discernible advantage to or bias regarding the participants which might have caused them to fabricate an incident of sexual or physical abuse in the past, and many stated that this was the first occasion on which they had been asked about and had disclosed abuse. The assessment records were independently reviewed by a clinical psychologist who did not have access to the background documentation, to determine reliability. Whilst there are criticisms of the reliability and validity of standardized assessment procedures for the diagnosis of sexual disorders, especially with offenders with ID (Miller et al. 2005), in this study the diagnosis of sexual disorder was not addressed; the diagnoses which were canvassed included epilepsy, autism, depression, psychosis, post-traumatic stress disorder, suicidal ideation or attempts, and anxiety disorder.
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Inter-rater reliability was high (r ‡ 0.82, P < 0.00 for all diagnoses).
Results Prior history of being the victim of abuse The types of abuse reported by both groups of sex offenders as occurring during their developmental years is shown in Table 1, the only significant difference between the groups being that those with ID were more likely to report that they had been the victim of physical abuse during childhood.
Psychological ⁄ psychiatric disorders Table 2 shows the proportion of the groups who were diagnosed with a psychological, behavioural or psychiTable 1 History of prior abuse (more than one type of abuse recorded)
Prior abuse
Sex offenders with ID (n = 20)
Sex offenders non-ID (n = 20)
Physical abuse Sexual abuse Family conflict (verbal) Family violence observed
12 6 10 11
5 4 9 7
(60.0%) (30.0%) (50.0%) (55.0%)
(25.0%*) (20.0%) (45.0%) (35.0%)
*P < 0.05.
Table 2 Psychological, psychiatric and behavioural disorders (more than one disorder recorded)
atric disorder. Participants in the ID group were more likely to be diagnosed with depression (v2 = 6.67, d.f. = 1, P < 0.01), post-traumatic stress disorder (v2 = 9.23, d.f. = 1, P < 0.00) and aggressive behaviour (v2 = 4.91, d.f. = 1, P < 0.02). At the time of the assessment, most participants from both groups stated that they were not receiving any treatment or intervention. The majority of participants in both groups were likely to have a history of inappropriate sexual behaviour that had not been the subject of a criminal charge (77.5% of total group) in addition to the index offence. Within the ID group, those who demonstrated aggressive behaviour as an adult were significantly more likely to report that they had been the victim of childhood physical abuse (v2 = 12.85, d.f. = 1, P < 0.00) and that they had been exposed to family violence as a child (v2 = 5.08, d.f. = 1, P < 0.05) whereas there was no relationship between adult aggressive acts and prior exposure to violence for the non-ID group. For ID sex offenders, a history of family verbal conflict was related to suicidal ideation (v2 = 5.45, d.f. = 1, P < 0.03), and attempted suicide (v2 = 4.10, d.f. = 1, P < 0.05). Prior sexual abuse was related to suicidal ideation (v2 = 7.93, d.f. = 1, P < 0.01), and attempted suicide (v2 = 8.80, d.f. = 1, P < 0.00). In the case of non-disabled sex offenders, a history of family violence was related to depression (v2 = 7.17, d.f. = 1, P < 0.01), and so too was having been the victim of childhood physical abuse (v2 = 4.44, d.f. = 1, P < 0.05). A history of having been the victim of sexual abuse was related to attempted suicide (v2 = 6.66, d.f. = 1, P < 0.03), and anxiety disorder (v2 = 9.45, d.f. = 1, P < 0.01).
Offending patterns Symptom Depression Suicidal ideation Suicide attempts Post traumatic stress disorder Anxiety disorder Panic anxiety Personality disorder Aggressive behaviour Other inappropriate sexual behaviour *P < 0.05; **P < 0.01.
Sex offenders with ID (n = 20)
Sex offenders non-ID (n = 20)
16 5 7 11
(80.0%) (25.0%) (35.0%) (55.0%)
8 6 5 2
(40.0%**) (30.0%) (25.0%) (15.4%**)
8 7 8 14 16
(40.0%) (35.0%) (40.0%) (70.0%) (80.0%)
4 6 4 7 15
(20.0%) (30.0%) (20.0%) (35.0%*) (75.0%)
Both groups of sex offenders tended to be generalist offenders, with 64.3% having committed other offences of a non-sexual nature; no differences were noted between the groups. The victims of the sex offences were predominantly female for both ID and non-ID offenders (in 69.2% of cases). Sex offences were committed alone by the perpetrator with ID in 100% of instances, and by 85.7% of the non-ID offenders. Those perpetrators with ID who had been physically abused during their developmental years were significantly more likely to threaten violence during the offence (v2 = 9.73, d.f. = 1, P < 0.00), to use violence (v2 = 10.57, d.f. = 2, P < 0.00), or to use a weapon (v2 = 7.17, d.f. = 1, P < 0.01) compared with the non-ID group.
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Discussion The reported rates of having been the victim of child sexual abuse for sex offenders with ID in this study were slightly lower than rates reported by Lindsay et al. (2001) (30% versus 38%). Lindsay et al. (2001) found that sex offenders with ID were more likely to have been sexually abused in childhood compared with nonsexual offenders with ID, whereas the pattern was reversed for physical abuse. In the present study, sex offenders with ID were more likely to report having been the victims of physical abuse than sexual abuse. Lindsay et al. (2001) report that their information was obtained over the period of at least one year of treatment, and the longer duration of a relationship with one or more of the treating professionals may have resulted in greater likelihood of recalling or disclosing sexual abuse, although there may also be the possibility that some sex offender participants disclose sexual abuse because consciously or unconsciously they realize that the treating professionals are interested in this phenomenon, and because other members of the group disclose. General population samples of men show that 14.2% report childhood sexual abuse, whilst 22.2% of men report childhood physical abuse (Briere & Elliott 2003). A longitudinal community sample of boys indicated that 10% of participants had been maltreated by the age of 18, and the victims were more likely than the matched controls to have been referred to juvenile court (Stouthamer-Loeber et al. 2001). These rates are considerably lower than those reported by participants with ID in this study, although closer to the rates in the non-disabled group. Given the small sample size of the groups, however, these results must be regarded with caution. Whilst Lindsay et al. (2001) reported a relationship between type of offence and type of abuse, other authors do not report that link (Widom & Ames 1994; Williams et al. 1995). Recurrent extra-familial maltreatment, often co-existing with recurrent intra-familial maltreatment, was related to violent or sexual crimes in a small sample of juvenile offenders (Hamilton et al. 2002). These findings parallel other research indicating that both direct experience of being the victim of violence and also witnessing inter-parental violence are related to greater likelihood of the individual engaging in child abuse once they reach adulthood (Cunningham 2003). This suggests that not only the experience of abuse, but the recurrence of abuse and the sources of abuse need to be more clearly delineated and explored in future research.
However, the link between being a victim and being an abuser is not a straightforward situation involving social learning and imitation, with evidence suggesting that personality characteristics can mediate the link between the two (Ornduff et al. 2001). The personality and inter-personal factors found to be relevant include extreme self-doubt, social ineptitude, and a basic lack of understanding of causality in the social realm. Whilst Ornduff et al. (2001) researched a sample of women, it is clear that these types of personality characteristics could well be replicated in offenders with intellectual disabilities, both male and female. In this present research, exposure to family verbal conflict and prior sexual abuse were related to psychological â &#x201E; psychiatric disorders (specifically suicidal ideation and attempted suicide) for ID sex offenders, whereas family violence and having been the victim of child physical abuse were related to higher rate of disorders (specifically depression, attempted suicide and anxiety disorder) in the non-disabled group. It may be the case that some offenders with ID lack the insight, communication skills and self-awareness to describe the symptoms of depression and anxiety disorder, for example, and can more readily articulate more concrete experiences such as suicidal ideation and attempts at suicide. The results of this study cannot be directly compared with the study by Lindsay & Lees (2003) which found that sex offenders with ID reported lower mean levels of anxiety and depression than non-offenders with ID on modified versions of the Beck Anxiety and Depression Inventories. By comparison the results in the current study report numbers of participants reporting symptoms of these disorders, rather than comparisons of mean scores; on both anxiety and depression, more participants in the ID sex offender group than in the non-disabled sex offender group reported anxiety or depression, although the difference was non-significant for anxiety disorder. A major finding was the high rate of post-traumatic stress disorder in the ID group. The present data, together with other research, suggest a pattern which bears further targeted research. The aetiology and role of depression needs further examination, for instance. Lunsky (2003) reported that perceptions of stress and loneliness can be related to symptoms of depression among adults with borderline to moderate intellectual disabilities; future examination may determine if prior abuse is linked to subsequent perceived stress and isolation and therefore to depression. Dagnan & Sandhuâ&#x20AC;&#x2122;s (1999) finding that depression is related to low self-esteem and low group belongingness also bears further investigation in the context of
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sexual offences, particularly violent offences, because of the implications of social isolation in the commission of sex offences. Physical and sexual abuse in childhood occurred in a significant number of cases, and in the ID group, was related to threats of violence, use of violence and use of a weapon during the commission of the sexual offence. These findings are consistent with Lai’s results (1999) for non-disabled adolescents, showing exposure to violence at home, at school, or in the neighbourhood was linked to high levels of violent offences. The high rates of post-traumatic stress disorder, depression and aggressive behaviour in the ID group needs further investigation to determine whether depression and posttraumatic stress disorder are mediating factors in the commission of violent offences. If this is found to be the case, the early treatment of psychiatric disorders in people with ID who have been the victim of abuse may be instrumental in lowering offending rates. The findings of this research are limited by the retrospective nature of the information and the small group sizes, and therefore the results must be regarded with caution. Although tentative, however, the findings have important implications for future longitudinal research, as well as for prevention of sex offending behaviour through early interventions for people with ID who have been victims of physical, sexual or other forms of child abuse of neglect.
Correspondence Any correspondence should be directed to Susan Hayes, Centre for Behavioural Sciences, Discipline of Medicine, Central Clinical School, University of Sydney, NSW 2006, Australia (e-mail: s_hayes@bsim.usyd.edu.au).
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