Bliss points vs. minimum needs: Tests of competing motivational models.

This paper tests two competing hypotheses concerning the motivational forces underlying concurrent choice behavior: a generalized version of Staddon's minimum-distance hypothesis, which characterizes behavior in terms of minimizing the distance to a "bliss" point, and a generalized minimum-needs hypothesis, which emphasizes meeting minimum survival requirements first, after which the organism is free to allocate behavior in any fashion desired. The models specify distinctly different preference structures. The generalized minimum-needs hypothesis is shown to provide a superior fit to molar choice data from experiments involving food and fluid consumption.