Glynis H Murphy, Tizard Centre, University of Kent, & Neil Sinclair, Sinclair-Strong Consultants Ltd.


Since the 1980s, it has been known that people with intellectual disabilities are particularly likely to be sexually abused, compared to other care groups. It has turned out that most of the abusers are men, and that roughly 50% them are family members or staff. But roughly 50% are men who themselves have intellectual disabilities, often men sharing services of some kind with the victims (Turk and Brown 1993; Brown et al. 1995; McCarthy and Thompson 1997).

Remarkably little is known about men with intellectual disabilities and sexually abusive behaviour (Murphy, 2007), even though a very large literature exists concerning sex offenders without disabilities. However, the two groups do seem to share many similarities: both non-disabled sex offenders and sex offenders with intellectual disabilities often have a socially deprived up-bringing, in chaotic and sometimes neglectful families, where they are often themselves abused as children. Sexual abuse is massively under-reported to the police (According to Finklehor (1984), only 50% of victims ever tell anyone, let alone the police.), and it is thought that few abusers are brought to justice. Some people have argued that men who abuse people with intellectual disabilities are particularly unlikely to be convicted, as the victims are often not considered to be ‘safe’ witnesses in court because of their poor communication skills. It may also be that men with intellectual disabilities and sexually abusive behaviour are actually less ‘successful’ in keeping their behaviour hidden, than other men, since they have more supervision, fewer private spaces, less freedom to go out alone and have less-advanced planning skills than other men. This may result in a greater level of detection of sexually abusive behaviours in the intellectual disabled population, than would be possible in the mainstream population, even though it does not seem to lead to a greater level of convictions (Hayes and Craddock 1992).

Numbers of men with intellectual disabilities who abuse others

There are very few estimates of the prevalence of sexually abusive behaviour amongst men with intellectual disabilities, although Swanson and Garwick (1990) estimated that 3% of people with an intellectual disability showed sexually aggressive behaviour, and Hayes (1991) estimated that 4% of the men with intellectual disabilities in prison had been convicted of a sexual offence (from a prison survey in Australia).

Why do some men with intellectual disabilities abuse others?

Thompson and Brown (1997) have suggested that men may abuse others because they themselves have been sexually abused, and/or they lack opportunities for appropriate sexual expression, and/or they lack an understanding that such behaviour is illegal, and/or they over-identify with children, as a result of their own developmental immaturity.

There is circumstantial evidence for some of these hypotheses. For example, men with intellectual disabilities do have limited numbers of sexual partners compared to other people, and those men with intellectual disabilities who later become perpetrators of sexual abuse have more often been sexually abused as victims, compared to men with intellectual disabilities who later engage in different crimes (Lindsay et al 2001). However, there is very little evidence that they abuse others as a result of ignorance (indeed, they seem to have better sexual knowledge than other people with intellectual disabilities). Moreover as Thompson and Brown (1997) have pointed out, none of these explanations alone can account for why some men with intellectual disabilities display sexually abusive behaviour, whilst the vast majority do not. It is possible that other factors are more important, such as those in men without disabilities who commit sexual offences. For non-disabled men, it is thought that attachment problems, lack of empathy and cognitive distortions are the most important factors (See Marshall et al 1999, for a review in relation to mainstream sex offenders.).

Treatment for non-disabled sex offenders

Research shows that most non-disabled men with sexually abusive behaviour do respond to treatment, and it is generally agreed that cognitive behaviour therapy (CBT) (See, for example, Marshall et al.1999.) is the most effective type of treatment for these men, reducing reoffending by between a third and a half (Hanson et al. 2002; Kenworthy et al. 2003; Aos et al. 2006; Brooks-Gordon et al. 2006). In the UK, men who are convicted of a sexual offence and sent to serve a prison sentence, or to serve a community sentence overseen by probation services, can receive cognitive behaviour therapy, such as the prison or community versions of the SOTP (Sex Offender Treatment Programme), and this model does appear to be effective (Beckett et al. 1994). However, these programmes are normally restricted to offenders whose IQ is 80 or over and thus many sex offenders with an IQ below 80, are not offered such treatment.

Treatment for men with intellectual disabilities who sexually abuse others
There are some treatment programmes specially designed for men with mild or borderline intellectual disabilities. For example, there are some UK prisons that are running Adapted SOTP programmes (A-SOTP), designed for men with lower ability, including intellectual disabilities. In the research literature, there have also been sporadic reports of programmes or elements of programmes adapted for men with intellectual disabilities, but most studies have evaluated small samples of men either in the UK (Lindsay et al. 1998a, b, c; Lindsay and Smith 1998; Rose et al. 2002) or elsewhere (e.g. Swanson and Garwick 1990; Nezu et al.1998). Only a few studies had relatively larger samples:
■ Lindsay et al. (2006) showed a 70% reduction in harm amongst a group of 29 sexual offenders with intellectual disabilities who had a history of repeated offending, following community-based cognitive-behavioural treatment
■ Williams et al. (2007) showed significant pre-post treatment change on measures of attitudes, cognitive distortions, self-esteem and empathy in a group of over 150 men with cognitive deficits (by no means all of whom had intellectual disabilities), treated in prison using the A-SOTP programme.

Most recently, a series of reports have emerged from a group called SOTSEC-ID (Sex Offender Treatment Services Collaborative – Intellectual Disabilities). This group began in about 2000, and they now offer cognitive behavioural treatment across many sites (mainly in the NHS) in England and Wales, for men with intellectual disabilities who have sexually abused others, using a common treatment manual and a common set of assessment measures. The group also runs two-day training events for therapists (mostly run in London, twice a year) and eight-weekly meetings to support therapists running such treatment programmes (see ).

The SOTSEC-ID model involves a whole year of treatment, with group CBT for up to 8 men in each group, with two-hour sessions running once a week. The aim of the treatment is to reduce men’s sexually abusive behaviour. It is also expected that there will be positive change in men’s sexual attitudes and knowledge, their victim empathy, and their cognitive distortions in relation to sexual offending (e.g. degree of minimisation, denial for the offence(s) and blame for the victim), which are thought to underlie sexually abusive behaviour. The modules covered are as follows:
1. Human relations and sex education: The purpose of sex education for the men with intellectual disabilities and sexually abusive behaviour is to provide: A common knowledge base and understanding for human sexuality and relationships, including consent and legal issues; ‘permission’ to talk about sexuality and sexually abusive behaviour; and opportunities to challenge any myths/beliefs/attitudes/cognitive distortions regarding relationships, behaviour or gender roles which may contribute to sexually abusive behaviour

2. The Cognitive Model The treatment takes a cognitive approach to changing sexually abusive behaviour, through changing the men’s cognitive distortions, and this phase of the treatment introduces men to the cognitive model, i.e. to the idea that there are emotional and cognitive aspects to behaviour. This begins with non-offending examples (e.g. someone being upset because a promised visit did not take place) and gradually moves on to challenging behaviour/offending (e.g. wanting items in a shop, not having the money but shop-lifting) and finally to sexual offending (including the men’s own offences).

3. Victim Empathy Empathy has long been considered important for regulating and/ or mediating pro-social behaviour, motivating altruism and inhibiting aggression. It appears that low victim empathy may be related to some of the cognitive distortions that sex offenders hold, in that both minimisation of harm and victim blaming may be the result of low victim empathy. Various methods are used in the treatment to try to increase victim empathy. Initially the men are supported to talk about times when they were victims of bullying or abuse. They consider how they felt. The group then works towards getting the men to think about how victims of sexual abuse, generally, might feel. Finally they are helped to face up to how their own victims felt, something which most men find very hard.

4. Sexual Offending Model Finklehor’s 4-step model of sex offending provides the framework within which facilitators and participants discuss the men’s sexually abusive behaviour in the group and help them to understand it better, especially the various steps involved in the offending process. This part of the programme is intended to help the men see that their previous abusive sexual behaviour did not occur in a random or unexplained fashion, but that they planned to offend (and therefore that they can plan not to offend). The model provides a relatively simple framework for understanding sexual offending and forms a basis for relapse prevention. It proposes 4 steps to sexually abusive behaviour: thinking about sexually abusive behaviour (having ‘not OK’ sexy thoughts); making excuses about why this is OK; planning how to get access to a victim; engaging in sexually abusive behaviour. Each man is required to consider these steps in relation to his own past behaviour. In the process of discussion with the men, it usually transpires that they hold a variety of cognitive distortions (e.g. the belief that they didn’t plan their offences, they just ‘happened’). These cognitive distortions are then challenged, with the help of other men in the group, and each man is helped to develop a more honest account of how his sexually abusive behaviour occurred.

5. Relapse Prevention The relapse prevention module is designed to address the difficulty encountered in most sex offender treatment programmes, that of recidivism or failure of maintenance. The purpose of relapse prevention strategies is to provide the client with a range of strategies and tactics that will reduce the probability of encountering situations in which a lapse is likely, and reduce the likelihood of lapses becoming relapses. Such strategies are needed because, regardless of how powerful the initial treatment effect is, maintenance relies on self-administration of strategies and tactics to avoid relapse, and if such strategies are not explicitly addressed in treatment, the client is less likely to have the appropriate skills and knowledge to apply them. Towards the end of the treatment, a number of sessions are spent developing detailed relapse-prevention plans for each client. These serve as a summary of relevant points of the group treatment programme and are designed to be portable relapse prevention plans that the man can use at any time and that can also be shown to relevant parties such as the residential service and care manager.

Does the treatment work?

A number of studies now exist to show that the SOTSEC-ID model does have significant positive effects on the men’s sexual knowledge, empathy and cognitive distortions, and these changes seem to be maintained over periods of several years (Murphy et al. 2007; SOTSEC-ID 2010; Heaton and Murphy (in press)). Most men seem to stop offending after the treatment, but a small number of them do go on to continue sexual offending, though even for these men the abusive behaviours they show are far less severe.

Most treatment groups find that the men do best if they continue to attend an occasional ‘booster’ session after the end of their year of treatment, and most sites now also run ‘maintenance groups’ that meet about six-weekly.

So far, analyses of the risk factors that make men continue to offend have shown that the men’s level of ability, history of abuse, history of offending, type of offence and a variety of other factors do not seem to predict re-offending. It does, however, appear that men with an autism diagnosis do rather less well than those without such a diagnosis, although the reason for this is not yet clear.

What else needs to be done?

Cognitive behavioural treatment, like the SOTSEC-ID model, seems to be a promising way of preventing men from continuing sexually abusive behaviour. However, as yet there have been no randomised controlled trials of CBT for men with intellectual disabilities and sexually abusive behaviour (There have been some RCTs for men without disabilities.). Nevertheless, it seems that at last some treatment can be offered to these men who are often highly motivated to stop offending. Of course, alongside such treatment, there needs to be a good risk-management package built for each man and efforts to help each man to attain a ‘good life’ (Ward and Marshall 2004), in order to help the man to stop offending, but also to give him something to live for.

Professor Glynis Murphy is a chartered clinical and forensic psychologist and Fellow of the British Psychological Society. She was President of the International Association of the Scientific Study of Intellectual Disabilities (IASSID) between 2008-2012. She is co-editor of Journal of Applied Research in Intellectual Disabilities and works at the Tizard Centre, University of Kent.

Neil Sinclair is a Chartered Clinical Psychologist with Sinclair-Strong Consultants Ltd. He has extensive knowledge and experience in adult mental health. The aim of the service is to promote psychological wellbeing that enables individuals to maximise their potential, cope with challenging circumstances and live fulfilling lives.


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