Smiling at Others Nudges Recipients to Make Far-Sighted Choices: The Mediating Role of Interpersonal Trust

Despite the prevalence of intertemporal decision-making in interpersonal contexts, few studies shed light on how the facial expression of the proposer influences the recipient's intertemporal choices during human interactions. Addressing this gap, the authors conducted a three-experiment investigation into how smiling—one of the most important facial expressions conveying a willingness to engage in cooperative and pleasant social exchanges—shapes others’ intertemporal choices. Experiment 1 examined the effect of smiling on intertemporal choices in a real-life context; Experiment 2 focused on the mediating role of interpersonal trust in a laboratory setting; and Experiment 3 explored how environmental uncertainty moderated the influence of smiling on intertemporal choices. The results demonstrate that smiling led to more farsighted choices through the mediation of interpersonal trust, and environmental uncertainty moderated the mediating role of interpersonal trust. Thus, this research may provide a tool to nudge people into making far-sighted choices.