UC Santa Cruz

Whether another person is perceived as similar or different from oneself can lead to differing impressions of their inherent human-like qualities (Haslam, 2006). As the boundaries between human-computer interaction and computer-mediated communication become increasingly fuzzy, it is important to assess in which ways these humanization measurements may also apply to non-human agents. There is evidence for interventions involving motion synchrony that can strengthen interpersonal bonds and perhaps instill a sense of similarity between individuals who otherwise have little in common (Wiltermuth & Heath, 2009), but it is as yet unclear whether similar effects can be observed for interactions between human and non-human agents. In a series of three experiments, I investigate the effect of synchrony on interactions with machine agents in three health contexts (mental, physical, and social health), each designed to be successively more applicable to real-life interactions between humans and machines (using static robot therapists, a physical robot exercise coach, and then an anonymous on-line debate and a game-like activity with a supposedly human or machine addressee). Humanization ratings did correspond to robot preference, and participation in an optional mimicry task after the initial training did lead to more positive humanization scores for the robot that was designed to help, rather than replace human therapists (Experiment 1). Synchronized stretching exercises resulted in warmer responses during interactions with a physical robot than non-synchronous exercises (Experiment 2). People gave higher humanization ratings to supposedly human agents, and are more persuaded by synchrony with anonymous human agents or non-synchrony with machine agents (Experiment 3). This research provides evidence for the importance of synchrony and backstories in building positive interactions between humans and machine agents, as well as between humans and other humans in anonymized contexts. However, it is important to bear in mind that attitudes around the capabilities of machines as compared to humans can lead to different responses following synchrony exercises. For example, while participants are more persuaded by emotionally distant machine agents, non-threatening outgroup members receive greater humanization benefits from motion-matching activities.