Using Expectancy Violations Theory to Understand Robot Touch Interpretation

As robots are increasingly placed in direct interaction and often times in physical contact with people, understanding how touch by a robot influences interactions has become an important topic in HRI. Although prior research in HRI has shown robotic touch to elicit both positive and negative reactions, it remains an open question when and why touch is perceived as positive or negative. Here we apply expectancy violations theory (EVT) to shed light onto this question. We present an online study with N=142 participants that investigates the impact of context (touch after error vs. touch after no error) and robot appearance (social/animated face vs. non-social/blank screen) in shaping the perception of a robot's touch. We found that robot-initiated touch from a non-social robot was rated more positively after an error compared to ratings of the non-social robot touch after no error. Open-ended responses showed that people attach a wide array of meanings to the robot's touch, highlighting the importance of additional cues that are needed to ensure that people understand the intention of the touch.