Publication Date


Advisor(s) - Committee Chair

Leroy Metze, James Craig, Lois Layne

Degree Program

Department of Psychology

Degree Type

Master of Arts


Fourteen female rats divided into three age groups of 110, 160 and 240 days old were compared for amount of barpressing in the Protestant Ethic Effect choice situation. All subjects were maintained on a 23 hour water deprivation schedule and trained to barpress for a 10% sucrose solution. Training consisted of one 12 hour massed practice session then 15 daily training sessions followed by 5 days of testing. During testing the rats were placed in the center of the cage and allowed to obtain the reinforcer from either the drinking tube attached to the barpress mechanism or from an identical free drinking tube introduced at the beginning of testing. The amount of liquid consumed at the free liquid tube and barpress tube was recorded for each animal. A repeated measures analysis of variance showed that barpressing differences between the three groups and across the trials were statistically significant. However, the hypothesis that the younger rats would barpress for more reward than the older rats was not supported. Older rats barpressed for more reward than the younger rats. It was suggested that the older less active rats may have spent their time barpressing while the active young rats may have spent more time exploring the cage environment.


Psychology | Social and Behavioral Sciences

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