Observing and interpreting emotions or behavioral tendencies through facial expressions is essential for interpersonal communication. Facial features are important factors in constructing facial expressions, and information regarding emotions can be gathered from the position of a person’s eyebrows and mouth. We devised three experiments to observe and understand the influence of facial expressions (mouth shapes) and eyebrow movements on experiencing emotions. Specifically, we studied these elements through the stimulation of different eyebrow conditions with natural faces, faces with non-Duchenne smiles, and faces with Duchenne smiles. The results confirmed that the eyebrows and mouth are important aspects in the formation of facial expressions. They both influence experiencing emotions to different degrees and allow different emotional interpretations, especially in the presence of prominent facial features or when visual attention is focused on specific parts. The conclusions of this study contribute to the understanding of facial cues and the relationship between the eyes and the mouth in the interpretation of emotions. This study also provides a reference for enhancing specific impression needs when applying makeup or eyebrows.
