Aggression in rats as a function of target location in a double alley.

After training in a double alley for 100% food reward in each of two goalboxes, 14 male Long-Evans hooded rats were run on a partial reinforcement schedule with a target rat present in either the first goalbox or the second runway. The incidence of attack was objectively recorded in both locations. Significantly higher levels of aggression were recorded during nonreward trials than during reward trials in the goalbox, or during either nonreward or reward trials in the runway. The results are interpreted as support for the hypothesis that, in general, aggression is elicited by frustration, but that under certain conditions alternative responses to frustration may preclude aggression.