The animals in this experiment were run in a straight 30-foot alley with a food goal. Timing was semi-automatic. Successive procedures were as follows: (1) Each rat was given 20 manually guided, untimed, rewarded runs in isolation. (2) Each rat was given 80 unguided, untimed, rewarded runs in isolation. (3) Each rat was given 40 unguided, timed, rewarded runs in isolation. (4) On the basis of mean scores obtained in the third procedure, the rats were matched and paired within each sex group. These pairs were then given 40 unguided, timed, rewarded runs in pairs. (5) These pairs were then given 160 additional unguided, timed runs. In these 160 runs only the rat first attaining the goal box was rewarded. The results from the third procedure show that the group had been trained to a speed-of-locomotion plateau. Data from the fourth procedure show that interstimulation resulting from running in pairs produced an increase in speed of locomotion. Data from the fifth procedure show no evidence of a discrimination between the pre-goal winning situation and the pre-goal losing situation. It is concluded that if competitive behavior has been demonstrated it has not been identified. (PsycINFO Database Record (c) 2006 APA, all rights reserved)