Barbara Colombo¹, Claudia Rodella¹, Silvia Riva^{1, 2}, Alessandro Antonietti^1,

In the economic domain often people have to make decisions by taking into account the perceived intentions of the partners. The aim of this study was to test how the perception that the responder is lying affects proposers’ offers in the Ultimatum Game. Twenty undergraduates took part to the experiment by playing the role of proposers. They were matched with responders who could be sincere or lying. Participants’ eye movements while watching the partners presenting themselves were recorded and their decision style (intuitive vs. deliberative) was assessed through the PID scale. It emerged that proposers offered less money to partners who were perceived as deceiving. Visual strategies during the inspection of the partner varied according to his/her perceived truthfulness. Decision style modulated both money offers and eye-movement patterns. The study supports the notion that lie detection is crucial in economic decisions involving the interaction with other people and that visual behaviors, as well as stylistic differences, play a mediating role.

decision making, ultimatum game, lie, mindreading, eye movements, decision style