A preliminary, exploratory study based on a small sample called “Sexual knowledge and attitudes of men with intellectual disability who sexually offend,” published in Journal of Intellectual and Developmental Disability in June 2007 did not find that sex education made sexual offenders with an intellectual disability more dangerous.

The study is based on a comparison of 43 individuals with an intellectual disability who committed a sexual offence, with 43 individuals also with an intellectual disability who did not commit a sexual offence. The study did not conduct a comparison of individuals with and without an intellectual disability, and findings cannot be generalized to sex offenders without intellectual disabilities.

They conducted the study because they wanted to examine the issue of how sexual knowledge may be related to sexually inappropriate or deviant behaviour in individuals with intellectual disabilities. It has been suggested in the past that there may be two subtypes of individuals with intellectual disabilities who sexually offend. The first subtype, called Type I, is similar to individuals without intellectual disabilities who sexually offend: they have deviant ideas about sexuality, referred to as paraphilia or love of the unusual.

Type II are those individuals who commit sexually inappropriate behaviours for other reasons, such as a lack of knowledge about sexuality, or not knowing what behaviors are acceptable. This group may be seen as naïve offenders. A scientific term coined to describe such individuals is “counterfeit deviance.”

Counterfeit deviant behaviors are not typically associated with ongoing sexual fantasies or urges or the intention to either harm or humiliate others. They reflect instead the restricted life of the person with the disability, who may have been denied sex education in the past or not provided avenues to pursue sexual interests in a safe and appropriate way. The study sought to examine whether the counterfeit deviance hypothesis could be supported for some individuals who committed a sexual offence, but not all individuals.

This is what our study did find: Some sex offenders with intellectual disabilities (those referred to as Type I offenders) exhibited more sexual knowledge than a matched group of individuals also with intellectual disabilities who had not sexually offended. No differences were found in the knowledge of Type II offenders compared to individuals with intellectual disabilities who had not offended.

Another finding from the study was that when they looked at only those individuals from both the offending (two types) and non-offending groups who had received sex education in the past and compared them in terms of total sexual knowledge, there were no differences between groups.