Research into the neuropsychological basis of impulsivity indicates that it may convey risk for substance misuse through an increased motivation to obtain rewards ("reward drive") and a propensity to act without forethought ("rash impulsiveness"). A recent model of disinhibition has also specified a role for Neuroticism in those with left hemispheric preference, due to the association of this hemisphere with action goal tendencies. This study investigated the mediating role of reversal learning, a key component of adaptive decision-making, in the prediction of hazardous alcohol use from impulsivity traits. A sample of 165 college students were administered a probabilistic reversal learning task, the Alcohol Use Disorders Identification Test (AUDIT), Sensitivity to Reward scale to measure reward drive, 17 (Impulsiveness) to measure rash impulsiveness, Eysenck Personality Questionnaire - Revised, and a self-report measure of ear preference to determine hemispheric preference. Results support the role of reward drive and rash impulsiveness in alcohol misuse, as well as rash impulsiveness, Neuroticism and lateral preference in poor reversal learning. However, there was no support for mediation, or an interaction between Neuroticism and lateral preference. (C) 2009 Elsevier Ltd. All rights reserved.