EFFECT OF RELATIVE REINFORCEMENT DURATION IN CONCURRENT SCHEDULES WITH DIFFERENT REINFORCEMENT DENSITIES: A REPLICATION OF DAVISON (1988)

Previous studies have challenged the prediction of the Generalized Matching Law about the effect of relative, but not absolute, value of reinforcement parameters on relative choice measures. Six pigeons were run in an experiment involving concurrent variable-interval schedules with unequal reinforcer durations associated with the response alternatives (10 s versus 3s), a systematic replication of Davison (1988). Programmed reinforcement frequency was kept equal for the competing responses while their absolute value was varied. Measures of both response ratios and time ratios showed preference for the larger duration alternative and that preference did not change systematically with changes in absolute reinforcer frequency. Present results support the relativity assumption of the Matching Law. It is suggested that Davison’s results were due to uncontrolled variations in obtained reinforcement frequency. Keywords: choice, preference, overall reinforcer frequency, reinforcer magnitude, pigeons.