Taxing Cognitive Capacities Reduces Choice Consistency Rather Than Preference: A Model-Based Test

How do people make preferential choices in situations where their cognitive capacities are limited? Many studies link the manipulation of cognitive resources to qualitative changes in preferences. However, there is a widely overlooked alternative hypothesis, namely, that a reduction in cognitive capacities leads to an increase in choice inconsistency. We developed a mathematical model and followed a hierarchical Bayesian estimation approach to test to what extent a reduction in cognitive capacities leads to a shift in preference or an increase in choice inconsistency. Using a within-subject n-back task to manipulate cognitive load, we conducted three experiments across different choice domains: risky choice, temporal discounting, and strategic interaction. Across all three domains, results show that a reduction in cognitive capacities predominantly affected participants' level of choice consistency rather than their respective preference. These results hold on an individual and a group level. In sum, our approach and the mathematical model we used provide a rigorous and general test of how reduced cognitive capacities affect people's decision-making.