The study, which will be published in the July 2009 issue of the journal Alcoholism: Clinical and Experimental Research, used selective breeding of mice and ended up with two genetically different lines. One group of mice drank high volumes of alcohol; the other group avoided alcohol. They tested impulsivity by offering two types of rewards: a small reward the mice could get immediately, and a larger, better award for which the mice had to wait.
The researchers found that the mice bred to prefer alcohol were more likely to go for the immediate yet smaller reward, a sign of impulsivity.
By extrapolating these results to humans, the researchers believe that early signs of risk factors for alcoholism would include behavioral disorders associated with impulsivity, such as ADHD and bipolar disorder.
B. G. Oberlin and N. J. Grahame. High-Alcohol Preferring Mice Are More Impulsive Than Low-Alcohol Preferring Mice as Measured in the Delay Discounting Task. Alcoholism Clinical and Experimental Research, 2009; DOI: 10.1111/j.1530-0277.2009.00955.x