Investigating the Effect of a Humanoid Robot’s Head Position on Imitating Human Emotions

Humans show their emotions with facial expressions. In this paper, we investigate the effect of a humanoid robot’s head position on imitating human emotions. In an Internet survey through animation, we asked participants to adjust the head position of a robot to express six basic emotions: anger, disgust, fear, happiness, sadness, and surprise. We found that humans expect a robot to look straight down when it is angry or sad, to look straight up when it is surprised or happy, and to look down and to its right when it is afraid. We also found that when a robot is disgusted some humans expect it to look straight to its right and some expect it to look down and to its left. We found that humans expect the robot to use an averted head position for all six emotions. In contrast, other studies have shown approach-oriented (anger and joy) emotions being attributed to direct gaze and avoidance-oriented emotions (fear and sadness) being attributed to averted gaze.