Procrastination by pigeons with fixed-interval response requirements.
Two experiments studied the phenomenon of procrastination, in which pigeons chose a larger, more delayed response requirement over a smaller, more immediate response requirement. The response requirements were fixed-interval schedules that did not lead to an immediate food reinforcer, but that interrupted a 55-s period in which food was delivered at random times. The experiments used an adjusting-delay procedure in which the delay to the start of one fixed-interval requirement was varied over trials to estimate an indifference point--a delay at which the two alternatives were chosen about equally often. Experiment 1 found that as the delay to a shorter fixed-interval requirement was increased, the adjusting delay to a longer fixed-interval requirement also increased, and the rate of increase depended on the duration of the longer fixed-interval requirement. Experiment 2 found a strong preference for a fixed delay of 10 s to the start of a fixed-interval requirement compared to a mixed delay of either 0 or 20 s. The results help to distinguish among different equations that might describe the decreasing effectiveness of a response requirement with increasing delay, and they suggest that delayed reinforcers and delayed response requirements have symmetrical but opposite effects on choice.
Mazur
J E
JE
Psychology Department, Southern Connecticut State University, New Haven, USA. mazur@scsu.ctstateu.edu
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D002755:Choice Behavior; D010856:Columbidae; D005247:Feeding Behavior / Q000523:psychology*; D008960:Models, Psychological; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology; D013997:Time Factors