Triggering Anthropomorphism or Depicting a Robot Character: The Effects of Human-like Timing of Emotional Expression in Human-Robot Interactions

Much work on human-robot interaction has shown that such interactions can profit from implementing human-like behaviors, in line with theoretical approaches that assume that human-like social cues ’trigger’ or ’evoke’ social behaviors towards the respective robotHowever, there is also evidence that people treat interactions with robots in special ways, that they have different expectations and attend to different communicative tasks than in interactions with other humans; especially those features that are geared towards efficiency in interaction seem not to be relevant or even perceived positively in human-robot interaction. In this paper, we investigate the effects of the relative timing of emotional expression while speaking; in a controlled in-person interactive experiment with N=56, participants interacted with a simulated robot that either presented certain emotional behaviors after the respective utterance or timed with the main content units during speech, which had been determined empirically in a prior study of interactions between humans. Results show that even though the ill-timed emotional expressions cause interruptions and problems with respect to turn-taking, participants prefer the robot that plays emotional behaviors after the utterance – thus deprioritizing the efficiency and turn-taking requirements of human interaction. The results thus support a constructive perspective on human-robot interaction, where participants engage in sophisticated sense-making based on the character depicted and their own understanding of the interaction situation.