Humans vs. Robots: Utilization of pointing cues and the mediators of trust in nonverbal communication

As robots are increasingly acting as communicative agents, it is critical to understand how individuals interpret and utilize their nonverbal information. Pointing gestures are a foundational form of nonverbal communication, yet it remains unclear whether robot-produced pointing is treated as equally communicative as human-produced pointing. The present study examined how pointing gestures were utilized when produced by a Human Hand, a Humanoid Hand, and a Tripod Gripper Hand, and how anticipatory looking related to perceived traits and trust. Eye tracking was used to capture anticipatory visual attention as a measure of cue utilization, alongside post-interaction assessments of trust and perceived agent attributes. Results indicated that participants utilized pointing cues made by the Human Hand and Humanoid Hand, but not by the Tripod Gripper Hand, despite matched cue direction and cue reliability. Perceived trust was not directly associated with whether pointing cues were utilized between agent conditions. Perceived intelligence and likability emerged as the strongest predictors of trust, with lower perceived intelligence mediating the relationship between agent condition and trust for Tripod Gripper Hand relative to the Human Hand. Overall, these findings illustrate the necessity of utilizing behavioral measures with subjective evaluations while demonstrating that trust in nonverbal robotic communication contexts is shaped by evaluative perceptions rather than agent appearance or actions alone. These results offer practical implications for the design of social robots intended to communicate nonverbal information and highlight the importance of designing social robots whose perceived competence and social qualities support their role as effective nonverbal communicators.