The effects of an impolite vs. a polite robot playing rock-paper-scissors ´ Alvaro Castro-Gonz´ alez 1 , Jos´ e Carlos Castillo 1 , Fernando Alonso-Mart´ ın 1 , Olmer V. Olortegui-Ortega 1 , Victor Gonz´alez-Pacheco 1 , Mar´ ıa Malfaz 1 , and Miguel A. Salichs 1 Robotics Lab, Universidad Carlos III de Madrid Abstract. There is a growing interest in the Human-Robot Interaction community towards studying the effect of the attitude of a social robot during the interaction with users. Similar to human-human interaction, variations in the robot’s attitude may cause substantial differences in the perception of the robot. In this work, we present a preliminary study to assess the effects of the robot’s verbal attitude while playing rock- paper-scissors with several subjects. During the game the robot was pro- grammed to behave either in a polite or impolite manner by changing the content of the utterances. In the experiments, 12 participants played with the robot and completed a questionnaire to evaluate their impres- sions. The results showed that a polite robot is perceived as more likable and more engaging than a rude, defiant robot. 1 Introduction The attitude of a robot is an essential feature for creating socially interactive robots. Studies on this matter are aimed at enhancing the Human-Robot Inter- action (HRI). In this work, we focus on studying how the robot’s verbal attitude alters its attributions. To achieve our goal, we have created a HRI scenario in- volving real users and a social robot. In the experiment, the robot and the users played, one at a time, rock-paper-scissors. We modified the robot’s attitude by changing the verbal content of its utterances. Then, in some cases, the robot used polite words whereas, in others, the utterances were rude and impolite. The only difference between the polite and the impolite attitudes were the utterances the robot said, the rest of the game remained unchanged. In the literature, we can find some works focused on studying the robot atti- tude during the interaction. In this regard, Cramer found that a positive robot’s attitude was preferred by the users over an accurate robotic empathic behavior [3]. Furthermore, Lee et al. [5] conducted some experiments using the robot dog Aibo where the robot’s personality changed between introvert and extrovert. The first conclusion that they found was that participants could accurately recognize a robot’s personality based on its verbal and nonverbal behaviors. The second conclusion was that the participants preferred interacting with a robot with an opposed personality rather than a similar one. Moreover, Leite et al. described