Can the eyes reveal a person's emotions? Biasing role of the mouth expression

Abstract

In this study we investigated how perception of the eye expression in a face is influenced by the mouth expression, even when only the eyes are directly looked at. The same eyes appeared in a face with either an incongruent smiling, angry, or sad mouth, a congruent mouth, or no mouth. Attention was directed to the eyes by means of cueing and there were no fixations on the mouth. Participants evaluated whether the eyes were happy (or angry, or sad) or not. Results indicated that the smile biased the evaluation of the eyes towards happiness to a greater extent than an angry or a sad mouth did towards anger or sadness. The smiling mouth was also more visually salient than the angry and the sad mouths. We conclude that the role of the eyes as a "window" to a person's emotional and motivational state is constrained and distorted by the configural projection of an expressive mouth, and that this effect is enhanced by the high visual saliency of the smile.