To Shake or Not to Shake: Intuitive Reactions of Senior Adults to a Robot Handshake in a Western Culture

Robots have the potential to provide everyday life care and support for senior adults, but acceptance is essential for successful implementation in the domestic environment. Nonverbal social behavior can enhance this acceptance, and behavioral cues should be easy and intuitive to understand. However, which factors contribute to senior adults' intuitive understanding of social cues, such as handshakes? Our research aims to address this question using video observations and semi-structured interviews. Based on a thematic analysis and video observations, our findings indicate that some participants intuitively understood how to shake hands. Most did not shake hands due to not understanding the robot's behavior or fear. Other identified themes included: contributing features for intuitive handshakes, design improvements, and experiences with the robot's end effector. Lastly, we found no significant effect between the initial response of the participants to the handshake and either the reaction time or the handshake duration. By designing the gripper and the robot itself in a more familiar, less fear-eliciting way, senior adults might understand the gesture of shaking hands more intuitively.