Abstract

Our study aims to investigate the role of motor and rational cues in driving interpersonal coordination. On one side, there is plenty of evidence that people may take advantage of motor representations to understand others’ action; on the other side, agents involved in strategic interactions are expected to act rationally. What if motor cues and rationality are conflicting when we have to predict (and accordingly adjust with) our partner’s action? To answer this question, we used an online cooperative game with a (fictional) partner, who could either behave rationally (choosing a high reward) or irrationally (choosing a low reward). Participants were instructed to achieve coordination with their partner in order to obtain a monetary reward, based on their success in coordinating upon high or low reward. Importantly, participants could observe part of the kinematic or the partner’s action, indicating if the partner would choose high or low reward. Our results show that rational thinking drives decision making when motor cues are not informative about the partner’s action. Conversely, when motor cues are informative, participants are ready to coordinate even upon low reward.