Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Kennon Andy Lattal

Committee Member

Michael Perone

Committee Member

Natalie Shook


The variables affecting social behavior are myriad, making the prediction and control of behavior occurring in social contexts relatively difficult. One can attempt to create a controlled social context in the laboratory by introducing a second organism into an operant chamber. To investigate effects of social stimuli on operant responding, key pecking responses of three pigeons were maintained on a variable-interval (VI) schedule of reinforcement in Experiment 1, and the key pecking responses of three additional pigeons were maintained on a three-component multiple schedule in Experiment 2. The components included a variable-ratio (VR) schedule, a fixed-interval (FI) schedule, and a differential reinforcement of low rate behavior (DRL) schedule. No social stimuli were present in the operant chamber during the baseline conditions of either experiment. During experimental conditions a mirror was introduced into the operant chamber to simulate the presence of another organism. The mirror covered one side wall of the chamber adjacent to the work panel containing the response key. Relative decreases in rates of responding were observed during each experiment when the pigeons had access to their reflections compared to when no mirror was present. Response rates returned to baseline levels when the mirror was removed in the subsequent conditions, suggesting that access to visual-social stimuli disrupted pigeon behavior controlled by different schedules of reinforcement.