The Effect of Preference Expression Modality on Self-Control

The marketplace affords consumers various modalities to express their preferences (e.g., by pressing a button on a vending machine or making an oral request at a restaurant). In this article, we compare speaking to manual preference expression modalities (button-pressing, writing, and taking) and study their effect on self-control dilemmas. Based on studies of the Stroop task and on neuroscientific evidence, we predict that speaking is less likely than motor movement to evoke self-control. Our prediction relies on the observation that different expression modalities activate different regions of the anterior cingulate cortex and hence may influence the extent to which emotions rather than cognitions determine an individual's decision. In six studies conducted both in the lab and the field, we show that speaking prompts more indulgent choice than manual modalities (studies 1a, 1b, 2, 3, and 4) but not when individuals speak in a foreign language (study 5).