Effects of reinforcer magnitude on reinforced behavioral variability

Eight pigeons were exposed to a two-component multiple schedule. In each component, four-peck sequences across left and right keys were reinforced according to a variability threshold contingency. In one condition, only infrequently occurring response sequences were reinforced in each component, thereby generating highly variable sequences. In a separate condition, when the variability threshold contingency was lenient in each component, sequences were much less variable. In each condition, reinforcer magnitude was manipulated across components, and the larger reinforcer magnitude produced less variability than the smaller reinforcer magnitude. These results suggest that larger reinforcers hinder the reinforcement of behavioral variability. The results are interpretable in terms of the larger reinforcer inducing a greater level of behavioral repetition, particularly as the time to reinforcement was approached. This effect may have implications for reinforcing behavioral variability in humans.