Paradoxical preferences when options are identical

Normative models of choice predict no preference when unequally priced options of identical quality are temporarily offered for the same low price, yet several studies using nonhuman subjects have found a preference in this context. Paradoxically, subjects have preferred the stimulus associated with typically higher acquisition cost. Here, preference tests were conducted for gray jays (Perisoreus canadensis) choosing between temporarily identical options, which were color coded to represent typical conditions. During no-choice trials, subjects were offered either a cheap or an expensive food reward, by positioning the reward either 1.9 or 60 cm into a tunnel. During intermittent free-choice trials, subjects chose between color-coded but otherwise identical options (same reward, both cheap). Jays preferred the stimulus associated with lower cost, unlike subjects in previous studies. To reconcile these conflicting findings, we model choice as a trade-off between state and predation. We explore how alternative mechanisms of valuation may lead to preference in either direction (i.e., for greater workload vs lower predation risk). Our models accommodate observed paradoxical preferences in both directions.