Do High-risk Prisoners Entering Treatment Have Clinically Impaired Cognitive Impulse Control?

Moffitt's (1993) developmental theory suggests that offenders on the life-course persistent (LCP) trajectory inherit or acquire neuropsychological deficits that compromise impulse control, and ultimately contribute to criminality. Empirical tests of this notion with adult LCP offenders are rare; the expected degree of impairment and which mechanisms are unclear. This research adopted a neurocognitive framework that proposes three cognitive mechanisms of impulse control: decision-making, perceptual control, and motor impulse control. Participants were 77 adult males, predominantly LCP prisoners completed five assessment tasks during pre-treatment assessment. Overall, proportions of impairment were unexpectedly low within and across cognitive impulse control domains. The highest proportions of impairment were observed on tasks requiring cognitive flexibility and sustained attention, and only cognitive flexibility uniquely predicted estimated pre-treatment violence risk. Results suggest the need to disaggregate cognitive from personality and behavioural variants of impulsivity and to further investigate how impaired cognitive flexibility affects progress during and following treatment.