The role of realism in perceiving neutral expression eyes

The eyes tell us a person’s sex and age. The pupils may also determine a person’s attractiveness, trustworthiness, intelligence, and emotional arousal and valence. This study investigated whether these characteristics could be perceived when looking at eyes with different pupil sizes. Participants completed one of two online experiments and rated eight colored Caucasian eye pictures with big, medium, small, and vergence pupils. The pupils were exaggerated (Experiment 1) or realistic (Experiment 2). Both experiments were identical except for the stimuli. Participants also rated the eyes’ realism and familiarity. All characteristics were on a 9-pt Likert scale. Participants finished the experiment by completing some personality assessments. Results from Experiment 1 revealed significant rating differences between pupil sizes for all characteristics except sex, age, and arousal. Big and medium pupils were received higher ratings than small and vergence pupils. Results from Experiment 2 only indicated rating differences for intelligence. This meant that pupils could influence how a person’s characteristics were perceived from the eyes. We conducted additional analyses to compare data across experiments. Ratings differed for attractiveness, trustworthiness, intelligence, realism, familiarity, and valence between experiments. The greatest difference was for realism. Participants’ personality ratings also differed between experiments for neuroticism, openness, and emotionality. This suggested that stimulus realism and participants’ personality contributed partly to the findings. Compared to other variables, realism contributed to the great differences across experiments due to its large effect size. We concluded that stimulus realism was important in shaping how the pupils influenced the perceived characteristics of another person and discussed the importance of investigating gaze from the pupils.