The Contribution of Cognitive Impulsivity to Criminal Risk

Impulsivity increases risk for general, violent and sexual offending. Accordingly, helping offenders to become better regulators of their impulses is one goal of offender rehabilitation. In a correctional setting, the assessment of impulsivity focuses on personality and behaviour, but not cognition; cognitive impulse control impairments are inferred from personality styles and behavioural patterns suggestive of acting before thinking. However, empirical findings challenge the validity of inferring cognition from personality and behavioural measures. Additionally, without assessing cognition, practitioners are limited in their ability to isolate which cognitive processes are most impaired and therefore worthy of intervention for individual offenders.  To establish the contribution of cognitive impulse control to criminal risk, a theoretically derived, empirically supported neurocognitive assessment framework was adopted. The framework is based on the notion that impulsive behaviour arises from three, potentially dissociable skill domains that support impulse control: decisionmaking, perceptual and motor impulse control. A cohort of 77 men attending intensive cognitive-behavioural rehabilitation was recruited from four of New Zealand’s prison-based Special Treatment Unit Rehabilitation Programmes (STURPs). A neurocognitive battery of five tasks collectively representing each cognitive impulse control domain was administered before and after the 8-month treatment programme.  Study One explored pre-treatment clinically impaired performance within and across each cognitive impulse control domain. Compared to normative data, performance was typically in the average to below average range, but it was not clinically impaired overall. When performance was clinically impaired, it was most pronounced on tasks requiring cognitive flexibility.  Study Two explored treatment change in cognitive impulse control. The study also compared pre-treatment cognitive impulse control between offenders who went on to complete the treatment programme and those who were prematurely removed for responsivity or conduct-related issues. No pre-treatment cognitive impulse control differences were found between treatment completers and non-completers. Treatment completers displayed small pre-post treatment improvements in some areas of cognitive impulse control, but not others.  Study Three explored cross-sectional and predictive relationships between cognitive impulse control, dynamic criminal risk, trait anger and anger control. Although there was little association between these variables before treatment, some cognitive impulse control outcomes predicted post-treatment dynamic criminal risk, trait anger and anger control. Thus, the evidence suggested that certain aspects of cognitive impulse control might function as facilitators of treatment change.  Together, the findings highlighted the importance of evaluating cognitive impulse control as part of the risk assessment, and clinical formulation process. The findings also suggested that interventions designed to develop cognitive impulse control abilities either before, or as a complement to traditional cognitive-behavioural interventions, have the potential to maximise treatment response.