because asymmetry "signals past illness or injury". One study suggested people were able to "gauge beauty at a subliminal level" by seeing only a glimpse of a picture for one-hundredth of a second. Other important factors include youthfulness, skin clarity and smoothness of skin; and "vivid color" in the eyes and hair. However, there are numerous differences based on gender. A 1921 study of the reports of college students regarding those traits in individuals which make for attractiveness and repulsiveness argued that static traits, such as beauty or ugliness of features, hold a position subordinate to groups of physical elements like expressive behavior, affectionate disposition, grace of manner, aristocratic bearing, social accomplishments and personal habits. Grammer and colleagues have identified eight "pillars" of beauty: youthfulness, symmetry, averageness, sex-hormone markers, body odor, motion, skin complexion and hair texture. Traditionally in Samoa, body fat was acceptable or attractive. Facial features An Italian study published in 2008 studied the positions of the 50 soft-tissue landmarks of the faces of 324 white Northern Italian adolescent boys and girls to compare the features of a group of 93 "beautiful" individuals selected by a commercial casting agency with those of a reference group with normal dentofacial dimensions and proportions. The research found that, in comparison with the reference group, the attractive adolescents tended to have the following characteristics: the ratio between the volume of the forehead and that of the total face was larger; the nasal volume was smaller; the distance between outer canthi was larger; total facial height and depth were reduced. Some tendencies differed by age and sex: the facial volume was smaller in older attractive boys than in their peers, but bigger in attractive girls; the faces of older attractive adolescents were less rounded (bigger ratio between facial area and volume), but the reverse was true for girls of any age; attractive older boys had smaller angles of facial convexity with more acute profiles, while in girls the reverse pattern was found; the nasolabial angle was reduced in girls, but in older boys the effect was reversed; older attractive boys tended to have more prominent chins. The study concluded that attractive adolescents had more neotenous and juvenile features, but older attractive boys also showed tendencies towards sexual dimorphism. Contrary to common misconception, one study finds that non-severe facial scarring increases male attractiveness for short-term relationships. Symmetry Symmetrical faces and bodies may be signs