Differential effects of robot's touch on perceived emotions and the feeling of Kawaii in adults and seniors.

Using social robots is a promising approach for supporting senior citizens in the context of super-aging societies. The essential design factors for achieving socially acceptable robots include effective emotional expressions and cuteness. Past studies have reported the effectiveness of robot-initiated touching behaviors toward interacting partners on these two factors in the context of interaction with adults, although the effects of such touch behaviors on them are unknown in seniors. Therefore, in this study, we investigated the effects of robot-initiated touch behaviors on perceived emotions (valence and arousal) and the feeling of kawaii, a common Japanese adjective for expressing cute, lovely, or adorable. In experiments with Japanese participants (adults: 21-49, seniors: 65-79) using a baby-type robot, our results showed that the robot's touch significantly increased the perceived valence regardless of the expressed emotions and the ages of the participants. Our results also showed that the robot's touch was effective in adults in the context of arousal and the feeling of kawaii, but not in seniors. We discussed the differential effects of robot-initiated touch between adults and seniors by focusing on emotional processing in the latter. The findings of this study have implications for designing social robots that have the capability of physical interaction with seniors.