Self-reported impulsivity in male offenders with low cognitive ability in New South Wales prisons

Abstract

The study of impulsivity in offenders with low cognitive ability has received relatively little empirical investigation. A sample of 108 male offenders with IQ scores below 75 points answered an adaptation of the Barratt Impulsiveness Scale version 11 (BIS-11). The adapted version had high reliability, and results showed the instrument is useful in discriminating sex offenders from both violent offenders, and non-sex offenders with low cognitive ability. Sex offenders with low cognitive ability achieve better planning scores, while other offenders with low cognitive ability show increased impulsiveness in terms of scores indicating quicker decision making, and a reduced amount of concern for the consequences of their actions. The study highlights the stability of impulsivity according to historical offences. Overall results indicate that the combination of acting without thinking, and lack of concern for consequences, differentiates offenders with low cognitive ability from many other offenders. Neither age nor IQ scores are significantly related to impulsivity in this group.

Keywords:

• impulsivity
• low cognitive ability
• offenders
• sex offenders
• violent offenders

Notes

1. While a range of results are presented, due to the large number of calculations undertaken in this study, which lead to an increased possibility of chance results, the discussion will focus on mainly those results that are significant at p≤0.01. The effect size is also used in discussion as it reflects practical concerns.