ABSTRACT
Choice between a larger, more delayed reinforcer and a smaller, less delayed reinforcer has been described as a self-control paradigm by many researchers working with animals (see, for example, Ainslie, 1974; Grosch & Neuringer, 1981; Rachlin & Green, 1972). Like humans, animals sometimes choose the larger, more delayed reinforcer, and sometimes the smaller, less delayed reinforcer. Individual animals exposed to identical conditions in an experiment may or may not choose the larger, more delayed reinforcer. For example, in Ainslie’s (1974) experiment, 3 out of 10 pigeons learned to precommit themselves to the larger, more delayed reinforcer. Other experiments with animals have shown that it is possible to increase the probability of subjects choosing the larger, more delayed reinforcer by gradually introducing shorter or longer delays (Fantino, 1966; Ferster, 1953; Logue & Mazur, 1981; Mazur & Logue, 1978). Any quantitative model purporting to account for choice between reinforcers of varying sizes and delays will have to describe individual differences, including any effects of experimental histories.
