"Speech and Evaluability: How Listening to Options Can Affect Choices and Evaluations," by Kurt Munz and Vicki Morwitz.
2023 Bocconi Junior Research Grant
As voice-based interfaces increasingly mediate daily decisions, understanding how communication modality shapes judgment becomes critical. Prior research suggests speech can enhance persuasion and person-perception, or it can lead listeners to focus on negative information. We propose that speech does not inherently produce more positive or negative evaluations. Instead, drawing on evaluability theory, we argue that the ephemerality of spoken information impairs the effective use of low-evaluability attributes (features that derive meaning primarily through comparison), which can result in less-extreme attitudes. Across five preregistered experiments (N = 5,518 adults), we demonstrate that speech-based (vs. text-based) presentations yield less-polarized comparative attitudes, reduce sensitivity to benchmarks, attenuate joint–separate preference reversals, and lower choice uptake for comparatively superior options. These effects were specific to comparative tasks; in non-comparative contexts, judgments were indistinguishable across modalities. We further demonstrate that the effect is driven by the ephemerality of speech: making text ephemeral produced results identical to speech. These findings suggest that modality effects in judgment and decision-making are moderated by the comparative nature of the evaluation. This research provides a theoretical bridge between communication modality and evaluability theory, with practical implications for the rapidly growing domain of voice-mediated choice.