‘Vẻ đẹp Mỹ’ tại Detroit 2007

Variability in preferences

It has been shown that women prefer more masculine men during the fertile period of the menstrual cycle and more feminine men during other parts of the cycle.[25] This distinction supports the sexy son hypothesis, which posits that it is evolutionarily advantageous for women to select potential fathers who are traditionally masculine rather than the best caregivers.[26] Masculine facial features are characterized by a prominent chin, strong brow, a strong nose, pronounced mouth and lips, a high forehead[citation needed] and a prominent lower jaw whereas feminine features are less pronounced. According to one study, men with facial scars are more attractive to Western women seeking short-term relationships; this may be due to the perception that facial scars are a symbol of high testosterone and masculinity.[27]
[edit] Long legs

One study suggested women prefer men with longer legs. Research compared the attractiveness of men of similar height but with different lengths of their legs and concluded that women found longer legs to be more attractive. Researchers hypothesized that longer legs were not only an aesthetic feature but indicated good health.[28]
[edit] Determinants of female physical attractiveness
The beauty of Maud Gonne (pictured here ca. 1900) was enough to drive the poet William Butler Yeats half mad.

Features such as a symmetrical face, full lips, and low waist-hip ratio are commonly considered physically attractive when part of a female, because they are thought to indicate physical health and high fertility to a potential mate. The determinants of female physical attractiveness include those aspects that display health and fitness for reproduction and sustenance. These include correlates of fertility such as youth,[29] waist-hip ratio,[30] breast size,[31] breast symmetry,[32] body mass proportion[33] and facial symmetry.[34][35] Though it has been said that facial attractiveness and symmetry signal good health, it has been questioned and said not to be highly related to good health.[36]
[edit] Facial alignment

In a study by University of Louisville psychologist Michael Cunningham, dimensions and proportions of what was regarded as attractive emerged with remarkable consistency. The ideal attractive female face featured "eye width that is three-tenths the width of the face at the eyes' level; chin length, one-fifth the height of the face; distance from the center of the eye to the bottom of the eyebrow, one-tenth the height of the face; the height of the visible eyeball, one-fourteenth the height of the face; the width of the pupil, one-fourteenth the distance between the cheekbones; and the total area for the nose, less than 5 percent of the area of the face."[37] Very small differences mattered; for example, "the ideal mouth was half or 50 percent the width of the face at mouth level; if that percentage varied "by as little at 10 points," the face was rated as less attractive.[37] The study found the "beauty of the female face ... is mathematically quantifiable."[37]

Desired traits were large female eyes, small chin and nose, and these "infantlike features draw out in them the same caretaking response a baby would–they make a woman seem cute and adorable."[37] Further, high wide cheekbones and narrow cheeks are "signs that a woman has reached puberty" and "high eyebrows, dilated pupils and wide smile" signal excitement and sociability.[37] One psychologist speculated there were two opposing principles of female beauty: prettiness and rarity. So average, symmetrical features is one ideal, while unusual, stand-out features is another.[38]