Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Alyce M. Dickinson

Second Advisor

Dr. Dale Brethower

Third Advisor

Dr. John Nangle

Access Setting

Masters Thesis-Open Access


The objective of this study was to compare the effects of mechanically-delivered and human-delivered reinforcement on the performance of intrinsically interesting tasks. The study used a multiple-trial within-subject comparison design in which two reinforcement phases (a human-delivered reinforcement and a mechanically-delivered reinforcement phase) were alternated with two post-reinforcement phases. Three of the four subjects did not show performance decrements following mechanically-delivered reinforcement while three did show decrements following human-delivered reinforcement. These data indicate that post-reinforcement decrements may be more likely when reinforcement is delivered socially, suggesting that such decrements may not be due to the reinforcers per se but to the way in which the experimenter interacts with the subject when reinforcers are delivered. Therefore, in practical settings, one need not abandon performance-contingent reward systems because of potential detrimental effects on intrinsic interest, but simply alter the way in which rewards are provided.