Early commitment facilitates optimal choice by pigeons

Thomas R. Zentall, Jacob P. Case, Jonathan R. Berry

Prior commitment has been found to facilitate choice of a larger later reward (e.g., healthy living) and avoid the impulsive choice of the smaller immediate reward (e.g., smoking, drug taking). In this research with pigeons, we investigated the ephemeral choice task in which pigeons are given a choice between two alternatives, A and B, with similar reinforcement provided for each; however, if they choose A, they can also choose B, whereas if they choose B, A is removed. Thus, choosing A gives them two rewards, whereas choosing B gives them only one. Paradoxically, pigeons actually show a preference for B, the suboptimal alternative. We tested the hypothesis that pigeons made suboptimal choices because they were impulsive. To reduce impulsivity, we required the pigeons to make their initial choice 20 s before receiving the first reward. We found that requiring the pigeons to make a prior commitment encouraged them to choose optimally. The control group, for which the reward was provided immediately following initial choice, continued to choose suboptimally. The results confirm that requiring animals to make a prior commitment can facilitate the development of optimal choice. Furthermore, they may help explain why, without prior commitment, impulsive species, such as primates and pigeons have difficulty with this task, whereas presumably less impulsive species, such as wrasse fish and under some conditions parrots, are able to choose optimally even without prior commitment.