With the rapid advancement of robotics, robots’ helping behaviors are increasingly framed not only as functional assistance but also as prosocially meaningful interaction. In this context, the resource cost borne by the help-provider is a critical factor, yet it has not been systematically explored in existing human-robot interaction (HRI) research. Understanding how humans perceive and respond to different types of helping is essential for building better human–robot relationships. This study addresses this gap through two experiments. Study 1 examined the role of agent resource type (robot’s own resources vs. external resources). Results showed that when robots shared their own resources, participants did not report significant differences in overall attitudes or prosocial behavior, but attributed higher performance trust and expressed stronger feelings of gratitude and guilt. Study 2 further examined the importance of agent resources (robot battery level: high vs. low) . The results showed that even when relative costs were the same, participants tended to perceive sharing from a low-battery robot as more reliable, while variations in resource type or importance did not significantly change social responses. These findings suggest that human evaluations of robots are shaped not only by the outcomes of helping but also by the perceived cost and sacrifice underlying robot actions. Our work offers an initial direction for integrating resource cost considerations into the design of social robots.

In this study, we explore how robot self-sacrifice can influence human perceptions and behaviors toward robots. While traditional research in human-robot interaction (HRI) often addresses moral dilemmas, such as the trolley problem, our work examines more relatable scenarios where robots engage in self-sacrificial behavior, such as offering their own battery to charge a user's device instead of relying on external resources. Through an experiment with 30 participants, we found that robots demonstrating self-sacrifice significantly promoted prosocial behaviors compared to robots that did not. However, no significant differences were observed between the groups in terms of the perceptions of robots. These results highlight that while self-sacrificial behavior did not alter perceptions of the robot's social traits, it clearly influenced participants' willingness to engage in prosocial actions. This research underscores the potential of robots to foster prosocial behavior through self-sacrifice, offering valuable insights for designing robots that encourage a flourishing society in which humans and robots coexist.

Understanding how different levels of robotic assistance influence human perception, trust, and prosocial behavior is critical in human-robot interaction (HRI) research. This study investigates how the cost of help provided by a robot affects human perception, trust, and prosocial behavior by presenting participants with a video-based experiment. In the experiment, participants observed a humanoid robot, Sota, providing assistance under two conditions: high-cost help, where the robot shared power from its own battery, and low-cost help, where the robot facilitated power transfer from an external mobile battery. Results showed that participants perceived the robot as more anthropomorphic and intelligent in the high-cost condition, with increased trust ratings in both performance and moral trust dimensions. However, no significant difference was observed in participants’ prosocial behavior towards the robot. These findings suggest that while higher-cost robotic assistance enhances perception and trust, it does not necessarily lead to greater prosocial responses from humans. This study contributes to the broader understanding of how varying levels of robotic assistance impact human social responses and has implications for designing socially interactive robots in cooperative settings.

Perspective-taking, which enables individuals to consider the thoughts and objectives of another, is well established to be a successful strategy for encouraging pro-social behavior in human-computer interactions. Nowadays, perspective-taking is no longer limited to text; it is now more frequently used in virtual reality (VR). However, most previous research has focused on simulating human-human interactions in the real world in VR by providing participants with experiences connected to different moral tasks. In this study, we investigated whether participants’ prosocial behaviors toward robots would change if they experienced an altruistic VR task involving robots from the perspective of different robots. Our findings show that participants who had the help-receiver-view exhibited more altruistic behaviors toward a robot than those who had the help-provider-view one in a dictator game. We believe that this work is the first attempt to investigate the relationship between perspective-taking in a VR environment and changes in prosocial behavior in human-robot interaction.

Abstract