Effects of Eye Size and Symmetry on Evaluating Appearances of Faces

A number of studies have revealed that eye size and symmetry were big factors of the attractiveness of a face. Each factor was investigated separately with no comparisons between themselves basing on the quality and quantity of each effect. In many articles, the "attractiveness" was used for explaining the importance of those factors from the viewpoint of evolutionary psychology. However, in some papers beauty and likability were used as a term of face preference. There has been little study to investigate these items simultaneously and the relations with the attractiveness. In this study, an experiment about beauty and likeability was conducted for the faces in which five types of eye sizes and symmetry were controlled, respectively. As the result, the largeness of the eye sizes increased the beauty/likeability of the face but extremely large eye lowered the evaluation value from the maximum. The highest rate of beauty/likeability was estimated at around 20% enlarged eyes of the intact eyes. On the other hand, the evaluation decreased monotonically according to the increase of the face asymmetry. By the comparison of the mean rating, there was no difference between beauty and likeability rating. From the analysis of the individual difference, however, it was clarified that some participants used the beauty and likeability in a different meaning. As the results showed consistent with that of the attractiveness, it suggested that other explanations not to be based on evolutionary psychology were necessary.