A different study performed by the same group found that ethanol-naïve iHAD rats were more impulsive in a DD task than iLAD rats (Wilhelm and Mitchell, 2008). Together with the current study, these data suggest that impulsive choice is heritable and could be an endophenotype for high alcohol consumption. The genetic risk factor for alcoholism in humans may be accounted for, at least in part, by an enhanced tendency to choose impulsively. Whether or not higher impulsivity causes higher alcohol drinking is unknown, but these data indicate that higher impulsivity precedes alcohol drinking and may be associated with it.
