2007). In addition, surprisingly, greater impulsivity has been found in DBA/2J mice compared to C57BL/6J mice (Helms, Reeves, & Mitchell, 2006), which is the opposite of what would be predicted by strain-based drug preferences. Although not conclusive at this point, these studies nonetheless reveal the interplay of genetic factors, impulsive discounting, and drug motivation without the typical confound of drug exposure in human studies.
