The effects of differing type and magnitude of reward on the contrafreeloading phenomenon in rats

Abstract

This investigation was made to determine the effects of the magnitude of reward on contrafreeloading, using food or water as reward. Two quantities were selected for each level of reward quality—a 20-mg-pellet food reward, a 45-mg-pellet food reward, a .01-cc water reward, and a .1-cc water reward. Seven days of training were followed by three test sessions. There was a significantly higher percent of contrafreeloding demonstrated with food as reward than with water and higher number of barpresses with small reward than with large. It was argued that a more appropriate measure should include reference to performance during training. In this approach, contrafreeloading with food and water were virtually the same.