A neuropsychological study of older adult first-time sex offenders

ABSTRACT

Background/Aims: The issue of whether sex offenders have cognitive deficits remains controversial. The objective of this study was to compare the neuropsychological function of older adult first time sex-offenders (FTSO), who had not previously been charged with a sexual offence prior to the age of 50, to historical long-term sex offenders (HSO) and non-sex offenders (NSO). The hypotheses were (a) that FTSO would demonstrate greater deficits in executive function, decision-making, and memory compared to non-sex offenders; and (b) the HSOs would present similar neuropsychological deficits to non-sex offenders.

Method: A battery of neuropsychological measures was administered to 100 participants comprising 32 FTSOs, 36 HSOs, and 32 NSOs.

Results: Both FTSOs and HSOs showed significant impairment on tests of executive function (including verbal fluency, trail-making, and the Hayling test of response inhibition) as well as on tests of verbal and verbal memory compared to NSOs; however, there was no difference between the two sex offender groups.

Conclusions: Older adult sex offenders, overall, demonstrated poorer neuropsychological performance than older adult non-sex offenders did, although there was no difference between older first-time and historical offenders. Cognitive deficits may increase the risk of sexual offending due to impaired capacity in self-regulation, planning, judgment, and inhibition. A proportion of older adult sex offenders may be harboring acquired frontal lobe pathology.

KEYWORDS:

• Neuropsychological assessment
• sex offenders
• pedophiles
• executive function
• Iowa Gambling Task
• frontotemporal dementia

Acknowledgements

Dr. Michael Hornberger and Dr. Oliver Piguet, Neuroscience Research, Australia.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

JRH is supported by Forefront, a collaborative research group dedicated to the study of frontotemporal dementia and motor neurone disease, from the National Health and Medical Research Council of Australia Program [Grant 1037746];the Australian Research Council Centre of Excellence in Cognition and its Disorders Memory Node [CE110001021].