Choices Refine Preferences: Deliberation Stabilizes Value Estimates

The spreading of alternatives (SoA) – increased valuation of chosen options and decreased valuation of rejected options – has commonly been explained as post-decisional rationalization. Here, SoA is examined as a consequence of deliberation, whereby decision makers refine noisy subjective value estimates and increase the precision and stability of their evaluations. A Bayesian updating framework yields discriminating predictions that distinguish this account from cognitive dissonance reduction. Across four studies (nine online experiments; N = 630) using repeated free-choice paradigms with snack foods, post-choice evaluations became more stable and more predictive of subsequent behavior, refinement generalized from overall value to attribute judgments and transferred across evaluative dimensions, and the effect depended on active deliberation rather than elapsed time alone. Additional analyses ruled out a purely statistical-artifact explanation. These findings suggest that choice-induced preference change can reflect deliberation-dependent information processing, with implications for preference measurement and the design of choice environments.