Sex Differences in the Shapes of Several Parts of the Young Japanese Face

Abstract

For the purpose of studying the sex differences of the human face we collected five separate images, which consist of several parts of the face, from frontal view photographs of 48 male and 52 female college students. We traced outlines of their faces with simple lines (traced items), and made reproductions of the photographs of their eyes, mouth and nose by using a copying machine (reproduced items). The test subjects were 16 males and 8 females. They looked at parts of the face shown in each image, and categorized them individually by judging on their sex. Then, we calculated the percentages of correct judgments (percentage correct) for each image. By comparing the percentage correct between male and female we concluded that the sex of the subjects did not affect the results of their judgments. In the traced items the percentage correct for the face as a whole, which contained the outlines of the eyes, mouth, nose and the lower jaw, was 69% but it decreased to 61% when the outline of the lower jaw was removed. Hence, the outline of the lower jaw appar-ently has a characteristic shape easily noticed by males. In the reproduced items the percentage correct was 65% for the eyes, 68% for the mouth and 58% for the nose. The mouth, therefore, has more distinguishing characteristics than the eyes or nose, especially with females. On the other hand, there is no correlation between the percentage correct for the eye, mouth and nose items. Hence, we concluded that the sexual specificity for the shape of the young Japanese face appears on their parts independently.