By Maria Misbach
A newly published paper co-authored by Eric VanEpps, associate professor of marketing, finds that people don’t fully appreciate how choice context can predict the strength of others’ preferences. The research shows that observers largely ignore the fact that choices made from limited sets of options should be less informative about preferences than choices made from larger choice sets.
The paper, “Choice Set Size Neglect in Predicting Others’ Preferences,” was published January 7, 2026, in Psychological Science.
“When we see another person make a choice, we often assume that choice reflects a strong, stable preference,” says VanEpps. “But we should appreciate that a choice made from only a couple of options—such as a vote for one of two flawed political candidates—doesn’t mean that a person fully supports their chosen option. It might just be the best of the options available.”
How choice set size shapes preferences
Across six preregistered experiments involving more than 10,000 U.S. adults, the researchers examined how people evaluate their own choices versus how they interpret others’ choices. Participants either made a choice themselves or observed someone else’s choice, while the number of available options varied.
When people chose for themselves, a clear pattern emerged. Selecting from a larger set increased how much they liked what they chose, because larger sets are more likely to contain a better match for one’s preferences. But when participants observed someone else making the same choice, they failed to apply this logic. A choice made from two options was treated much the same as a choice made from six.
This tendency, which the authors call choice set size neglect, reflects a broader bias in social judgment. Observers focus on the outcome of a decision while overlooking the context that shaped it.
Why people misread others’ choices
Eric M. VanEpps, Associate Professor of Marketing
The research shows that the issue is not a lack of understanding. When participants were explicitly prompted to compare choices made from
different-sized sets, or when decisions were framed as rankings rather than simple picks, sensitivity to choice set size increased sharply.
“These results suggest that people can reason correctly about choice context,” says VanEpps. “They just don’t naturally attend to it unless something draws their attention there.”
In everyday life, choices are typically observed in isolation, which makes it easy to overattribute decisions to personal taste rather than situational constraints.
Real-world implications
The findings have implications across marketing, management, policy, and everyday decision making. Organizations may overcommit to existing products or programs based on past selections without recognizing that those choices came from narrow menus. Gift givers may assume recipients strongly prefer items they already own. Leaders may misinterpret support for a decision made under limited alternatives as deep enthusiasm.
The research also highlights risks in highly constrained environments, such as two-option political systems, where observed choices can appear more polarized than underlying preferences truly are.
“The fewer options someone had, the less confidence we should have that their choice reflects a strong preference,” says VanEpps. “Ignoring that can lead to systematic misjudgments.”
About the research
“Choice Set Size Neglect in Predicting Others’ Preferences” was co-authored by Beidi Hu (University of Chicago Booth School of Business), Alice Moon (Georgetown University McDonough School of Business), and Eric VanEpps (Vanderbilt University Owen Graduate School of Management). The research was published in Psychological Science and is available online.
