The effect of avatar facial expressions on trust building in social virtual reality

In immersive virtual reality (VR) applications, the facial expressions and lip-syncing of an avatar can have a significant impact on a user’s experience. In this paper, we designed a VR “trust game” scene to evaluate the effects of four expression conditions (positive facial expressions, neutral facial expressions, negative facial expressions and no expressions and lip-syncing) on participants in an immersive VR scene. We measured the participants with both objective and subjective measures. The two objective behavioral measures were the level of investment in the “trust game” and the users’ eye-movement data, and the subjective measures included social presence, emotional awareness level, and user preferences. We found that the participants were generally less trusting of the avatars with negative expressions, while the avatars with positive expressions made the participants feel comfortable and thus increased their willingness to cooperate with the avatars. In conclusion, avatars with facial expressions, whether positive or negative, were more effective in influencing the participants’ trust levels and decision-making behaviors than those without facial expressions. These findings provide novel ideas and suggestions for improving the level of human–computer interaction in VR and enhancing user experience in VR scenes.