The effects of cognitive distortions in sex offenders and non-sex offenders with mild learning disabilities

  • Elaine Whitefield

Student thesis: Doctoral Thesis


Cognitive distortions of sexual offenders with or without learning disabilities are considered to play a vital role in the etiology and maintenance of sexually deviant behaviour. This assumption has driven research to focus on investigating the cognitive content of distorted cognitions held by sexual offenders. Indeed, to facilitate researchers in this quest, attention has focused on trying to develop psychometrically robust instruments to measure distorted cognitions. However, these attempts have met with little success, as current assessment measures fail to address a wide range of sexual attitudes, are not suitable for use on individuals with learning disabilities, are open to social desirability and some are unable to discriminate sexual offenders from normal males. To address these weaknesses a new measure has been developed by Lindsay (unpublished) to assess cognitive distortions among sexual offenders with learning disabilities (i.e. QACSO; Questionnaire on Attitudes Consistent with Sex Offences).

This thesis tested the reliability and validity of this new measure. Results found this measure to be a promising clinical and research instrument, with good internal consistency and reliability and discriminative ability. A principle component analysis revealed that 11 of the 13 components were reliable and successfully separated sexual offenders from controls. Results confirmed that sexual offenders with learning disabilities held significantly more distorted cognitions, compared to control groups of non-sexual offenders with learning disabilities, non-offenders with learning disabilities and normal males.

To develop understanding of the role cognitive distortions play in sexual offending behaviour it is not enough just to examine the cognitive content, as it is necessary to examine the cognitive processes (i.e. attention) that underlie the initiation, maintenance and justification of sexual deviant behaviour. This would result in better understanding of the cognitive processes that underlie behaviour at all stages of the offence chain and facilitate clinicians’ theoretical and practical ideas when developing suitable treatment programmes.

Studies two to six used a number o f experimental paradigms to investigate the cognitiveprocesses, and in particular attentional ability, of sexual offenders with learning ldisabilities. Study two investigated if conscious recollection of past events influenced the average time sexual offenders spent viewing pictures of people, compared to objects.Results found that the type of picture did not affect viewing time. To reduce the likelihood of conscious influence masking sexual offenders’ responses, studies three to six employed experimental paradigms that involve attentional ability being affected by prior experiences with no conscious recollection of past events. Results found sexual offenders with learning disabilities’ attentional abilities to be consistent with controls. Failure to obtain significant differences in the attentional abilities of sexual offenders compared to controls does not mean they do not have attentional deficits. Indeed, the methods employed might have been unable to detect any differences.

In light of these findings the appropriateness of the methods employed to investigate attentional abilities was discussed and recommendations for future were made.
Date of AwardOct 2003
Original languageEnglish
SupervisorDerek Carson (Supervisor)

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