Physical attractiveness

Venus de Milo at the Louvre has been described as a "classical vision of beauty". However, one expert claimed her "almost matronly representation" was meant to convey an "impressive appearance" rather than "ideal female beauty".

Xi Shi (西施), born 506 BC, was regarded as the most beautiful of the Four Great Beauties of ancient China.

Ishtar, Mesopotamian goddess of sexual love and war. The goddess has been associated with sexuality, love, and fertility.

Physical attractiveness is the degree to which a person's physical features are considered aesthetically pleasing or beautiful. The term often implies sexual attractiveness or desirability, but can also be distinct from the two. There are many factors which influence one person's attraction to another, with physical aspects being one of them. Physical attraction itself includes universal perceptions common to all human cultures, as well as aspects that are culturally and socially dependent, along with individual subjective preferences.

In many cases, humans attribute positive characteristics, such as intelligence and honesty, to physically attractive people without consciously realizing it. From research done in the United States and United Kingdom, it was found that the association between intelligence and physical attractiveness is stronger among men than among women. Evolutionary psychologists have tried to answer why individuals who are more physically attractive should also, on average, be more intelligent, and have put forward the notion that both general intelligence and physical attractiveness may be indicators of underlying genetic fitness. A person's physical characteristics can signal cues to fertility and health. Attending to these factors increases reproductive success, furthering the representation of one's genes in the population.

Men, on average, tend to be attracted to women who are shorter than they are, have a youthful appearance, and exhibit features such as a symmetrical face, full breasts, full lips, and a low waist-hip ratio. Women, on average, tend to be attracted to men who are taller than they are, display a high degree of facial symmetry, masculine facial dimorphism, and who have broad shoulders, a relatively narrow waist, and a V-shaped torso.

General contributing factors

The Mannerist movement was not afraid to exaggerate body proportions for an effect considered attractive; Juno in a niche, engraving by Jacopo Caraglio, probably of a drawing by Rosso Fiorentino, 1526

Generally, physical attraction can be studied from a number of perspectives, including universal perceptions common to all human cultures, cultural and social aspects, and individual subjective preferences. Additionally, the perception of attractiveness can have a significant effect on how people are judged in terms of employment or social opportunities, friendship, sexual behavior, and marriage.

Some physical features are attractive in both men and women, particularly bodily and facial symmetry, although one contrary report suggests that "absolute flawlessness" with perfect symmetry can be "disturbing". Symmetry may be evolutionarily beneficial as a sign of health 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 odour, motion, skin complexion and hair texture.

Male physical attractiveness

Women, on average, tend to be more attracted to men who have a relatively narrow waist, a V-shaped torso, and broad shoulders. Women also tend to be more attracted to men who are taller than they are, and display a high degree of facial symmetry, as well as relatively masculine facial dimorphism. With regard to male-male-attractiveness, one source reports that the most important factor that attracts gay men to other males is the man's physical attractiveness.

Facial attractiveness

Sexual dimorphism

File:Male female facial sexual dimorphism masculine feminine face.png

This is a remake of a facial geometric sexual dimorphism diagram from Valenzano, D. R. et al. (2006). The horizontal axis indicates geometric facial femininity, and the vertical axis indicates proportion of the population. The blue bell curve on the left represents the male faces, and the pink bell curve on the right represents the female faces. The purple area in the center represents the overlap of the two bell curves where the feminine male faces cannot be distinguished from the masculine female faces. The bell curves show that the proportion of female faces that are more feminine than the most feminine male faces is much greater than the proportion of male faces that are more masculine than the most masculine female faces.

Studies have shown that ovulating heterosexual women prefer faces with masculine traits associated with increased exposure to testosterone during key developmental stages, such as a broad forehead, relatively longer lower face, prominent chin and brow, chiseled jaw and defined cheekbones. The degree of differences between male and female anatomical traits is called sexual dimorphism. Female respondents in the follicular phase of their menstrual cycle (n = 55) were significantly more likely to choose a masculine face than those in menses and luteal phases (n = 84), (or in those taking hormonal contraception). However, women's likeliness to exert effort to view male faces does not seem to depend on their masculinity, but to generally increase with women's testosterone levels. It is suggested that the masculinity of facial features is a reliable indication of good health, or, alternatively, that masculine-looking males are more likely to achieve high status. However, the correlation between attractive facial features and health has been questioned. Sociocultural factors, such as self-perceived attractiveness, status in a relationship and degree of gender-conformity, have been reported to play a role in female preferences for male faces. Studies have found that women who perceive themselves as physically attractive are more likely to choose men with masculine facial dimorphism, than are women who perceive themselves as physically unattractive. In men, facial masculinity significantly correlates with facial symmetry—it has been suggested that both are signals of developmental stability and genetic health. One study called into question the importance of facial masculinity in physical attractiveness in men arguing that when perceived health, which is factored into facial masculinity, is discounted it makes little difference in physical attractiveness. In a cross-country study involving 4,794 women in their early twenties, a difference was found in women's average "masculinity preference" between countries.

A study found that the same genetic factors cause facial masculinity in both males and females such that a male with a more masculine face would likely have a sister with a more masculine face due to the siblings having shared genes. The study also found that, although female faces that were more feminine were judged to be more attractive, there was no association between male facial masculinity and male facial attractiveness for female judges. With these findings, the study reasoned that if a woman were to reproduce with a man with a more masculine face, then her daughters would also inherit a more masculine face, making the daughters less attractive. The study concluded that there must be other factors that advantage the genetics for masculine male faces to offset their reproductive disadvantage in terms of "health", "fertility" and "facial attractiveness" when the same genetics are present in females. The study reasoned that the "selective advantage" for masculine male faces must "have (or had)" been due to some factor that is not directly tied to female perceptions of male facial attractiveness.

In a study of 447 gay men in China, researchers said that tops preferred feminized male faces, bottoms preferred masculinized male faces and versatiles had no preference for either feminized or masculinized male faces.

In pre-modern Chinese literature, the ideal man in caizi jiaren romances was said to have "rosy lips, sparkling white teeth" and a "jasper-like face" (Chinese: 唇 紅 齒 白 、 面 若 冠 玉).

In Middle English literature, a beautiful man should have a long, broad and strong face.

Orthognathism

A study that used Chinese, Malay and Indian judges said that Chinese men with orthognathism where the mouth is flat and in-line with the rest of the face were judged to be the most attractive and Chinese men with a protruding mandible where the jaw projects outward were judged to be the least attractive.

Symmetry

Symmetrical faces and bodies may be signs of good inheritance to women of child-bearing age seeking to create healthy offspring. Studies suggest women are less attracted to men with asymmetrical faces, and symmetrical faces correlate with long term mental performance and are an indication that a man has experienced "fewer genetic and environmental disturbances such as diseases, toxins, malnutrition or genetic mutations" while growing. Since achieving symmetry is a difficult task during human growth, requiring billions of cell reproductions while maintaining a parallel structure, achieving symmetry is a visible signal of genetic health.

Studies have also suggested that women at peak fertility were more likely to fantasize about men with greater facial symmetry, and other studies have found that male symmetry was the only factor that could significantly predict the likelihood of a woman experiencing orgasm during sex. Women with partners possessing greater symmetry reported significantly more copulatory female orgasms than were reported by women with partners possessing low symmetry, even with many potential confounding variables controlled. This finding has been found to hold across different cultures. It has been argued that masculine facial dimorphism (in men) and symmetry in faces are signals advertising genetic quality in potential mates. Low facial and body fluctuating asymmetry may indicate good health and intelligence, which are desirable features. Studies have found that women who perceive themselves as being more physically attractive are more likely to favor men with a higher degree of facial symmetry, than are women who perceive themselves as being less physically attractive. It has been found that symmetrical men (and women) have a tendency to begin to have sexual intercourse at an earlier age, to have more sexual partners, and to have more one-night stands. They are also more likely to be prone to infidelity. A study of quarterbacks in the American National Football League found a positive correlation between facial symmetry and salaries.

Body scent

Main article: body odor

A number of double-blind studies have found that women prefer the scent of men who are rated as facially attractive. For example, a study by Anja Rikowski and Karl Grammer had individuals rate the scent of T-shirts slept in by test subjects. The photographs of those subjects were independently rated, and Rikowski and Grammer found that both males and females were more attracted to the natural scent of individuals who had been rated by consensus as facially attractive. Additionally, it has also been shown that women have a preference for the scent of men with more symmetrical faces, and that women's preference for the scent of more symmetrical men is strongest during the most fertile period of their menstrual cycle. Within the set of normally cycling women, individual women's preference for the scent of men with high facial symmetry correlated with their probability of conception.

Genetics

See also: Heterozygote advantage and Major Histocompatibility Complex and Sexual Selection

Studies have explored the genetic basis behind such issues as facial symmetry and body scent and how they influence physical attraction. In one study in which women wore men's T-shirts, researchers found that women were more attracted to the bodily scents in shirts of men who had a different type of gene section within the DNA called Major histocompatibility complex (MHC). MHC is a large gene area within the DNA of vertebrates which encodes proteins dealing with the immune system and which influences individual bodily odors. One hypothesis is that humans are naturally attracted by the sense of smell and taste to others with dissimilar MHC sections, perhaps to avoid subsequent inbreeding while increasing the genetic diversity of offspring. Further, there are studies showing that women's natural attraction for men with dissimilar immune profiles can be distorted with use of birth control pills. Other research findings involving the genetic foundations of attraction suggest that MHC heterozygosity positively correlates with male facial attractiveness. Women judge the faces of men who are heterozygous at all three MHC loci to be more attractive than the faces of men who are homozygous at one or more of these loci. Additionally, a second experiment with genotyped women raters, found these preferences were independent of the degree of MHC similarity between the men and the female rater. With MHC heterozygosity independently seen as a genetic advantage, the results suggest that facial attractiveness in men may be a measure of genetic quality.

Youthfulness

See also: Age disparity in sexual relationships

For the Romans especially, "beardlessness" and "smooth young bodies" were considered beautiful to both men and women. For Greek and Roman men, the most desirable traits of boys were their "youth" and "hairlessness". Pubescent boys were considered a socially appropriate object of male desire, while post-pubescent boys were considered to be "ἔξωροι" or "past the prime". This was largely in the context of pederasty (adult male interest in adolescent boys). Today, men and women's attitudes towards male beauty has changed. For example, body hair on men may even be preferred (see below).

A 1984 study said that gay men tend to prefer gay men of the same age as ideal partners, but there was a statistically significant effect (p < 0.05) of masculinity-femininity. The study said that more feminine men tended to prefer relatively older men than themselves and more masculine men tended to prefer relatively younger men than themselves.

A 2010 OkCupid study of 200,000 of its male and female customers found that women users are, except during their early to mid-twenties, open to searches from both somewhat older and somewhat younger men; they have a larger potential dating pool than men until age 26. At age 20, women, in a "dramatic change", begin sending private messages to significantly older men. Another such change occurs at age 29, accompanied by an end to messages to significantly younger men. Male desirability to women peaks in the late 20s and does not fall below the average for all men until 36. Other research indicates that women, irrespective of their own age, are attracted to men who are the same age or older as they themselves are.

Waist-to-chest ratio

The physique of a slim waist, broad shoulders and muscular chest are often found to be attractive to females. Further research has shown that, when choosing a mate, the traits females look for indicate higher social status, such as dominance, resources, and protection. An indicator of health in males (a contributing factor to physical attractiveness) is the android fat distribution pattern which is categorized as more fat distributed on the upper body and abdomen, commonly referred to as the "V shape." When asked to rate other men, both heterosexual and homosexual men found low waist-to-chest ratios (WCR) to be more attractive on other men, with the gay men showing a preference for lower WCR (more V-shaped) than the straight men.

Other researchers found waist-to-chest ratio the largest determinant of male attractiveness, with body mass index and waist-to-hip ratio not as significant.

Women focus primarily on the ratio waist to chest or more specifically waist to shoulder. This is analogous to the waist to hip ratio (WHR) that men prefer. Key body image for a man in the eyes of a woman would include big shoulders, chest, and upper back, and a slim waist area. Research has additionally shown that college males had a better satisfaction with their body than college females. The research also found that when a college female's waist to hip ratio went up, their body image satisfaction decreased. The results indicate that males had significantly greater body image satisfaction than did females.

Some research has shown that body weight may have a stronger effect than WHR when it comes to perceiving attractiveness of the opposite sex. It was found that waist to hip ratio played a smaller role in body preference than body weight in regards to both sexes.

Psychologists Viren Swami and Martin J. Tovee compared female preference for male attractiveness cross culturally, between Britain and Malaysia. They found that females placed more importance on WCR (and therefore body shape) in urban areas of Britain and Malaysia, while females in rural areas placed more importance on BMI (therefore weight and body size). Both WCR and BMI are indicative of male status and ability to provide for offspring, as noted by evolutionary theory.

Females have been found to desire males that are normal weight and have the average WHR for a male. Females view these males as attractive and healthy. Males who had the average WHR but were overweight or underweight are not perceived as attractive to females. This suggests that WHR is not a major factor in male attractiveness, but a combination of body weight and a typical male WHR seem to be the most attractive. Research has shown that men who have a higher waist to hip ratio and a higher salary are perceived as more attractive to women.

Flat abdomen

A 1982 study found that an abdomen that protrudes was the most unattractive physical trait for men.

In Middle English literature, a beautiful man should have a flat abdomen.

Musculature

See also: Bodybuilding

Men's bodies portrayed in magazines marketed to men are more muscular than the men's bodies portrayed in magazines marketed to women. From this, some have concluded that men perceive a more muscular male body to be ideal, as distinct from a woman's ideal male, which is less muscular than what men perceive to be ideal. This is due to the within-gender prestige granted by increased muscularity and within-gender competition for increased muscularity. Men perceive the attractiveness of their own musculature by the closeness their body resembles the "muscle man." This "muscle man" ideal is characterized by large muscular arms, especially biceps, a large muscular chest that tapers to their waist and broad shoulders.

In a study of stated profile preferences on Match.com, a greater percentage of gay men than lesbians selected their ideal partner's body type as "Athletic and Toned" as opposed to the other two options of "Average" or "Overweight".

In pre-modern Chinese literature, such as in The Story of the Western Wing, a type of masculinity called "scholar masculinity" is depicted wherein the "ideal male lover" is "weak, vulnerable, feminine, and pedantic".

In Middle English literature, a beautiful man should have thick, broad shoulders, a square and muscular chest, a muscular back, strong sides that taper to a small waist, large hands and arms and legs with huge muscles.

Genitalia

A 2006 study of 25,594 heterosexual men found that men who perceived themselves as having a large penis were more satisfied with their own appearance.

A recent 2014 study criticized previous studies based on the fact that they relied on images and used terms such as "small", "medium", and "large" when asking for female preference. The new study used 3D models of penises from sizes of 4 inches long and 2.5 inches in circumference to 8.5 inches long and 7 inches in circumference and let the women physically handle them. It was found that women overestimated the actual size of the penises they have experimented with when asked in a follow-up survey. The study concluded that women on average preferred the 6.5 inch penis in length both for long-term and for one-time partners. Penises with larger girth were preferred for one-time partners.

Height and erect posture

Females' sexual attraction towards males may be determined by the height of the man. Height in men is associated with status or wealth in many cultures (in particular those where malnutrition is common), which is beneficial to women romantically involved with them. One study conducted of women's personal ads support the existence of this preference; the study found that in ads requesting height in a mate, 80% requested a height of 6.00 feet (1.83 m) or taller. The online dating Website eHarmony only matches women with taller men because of complaints from women matched with shorter men.

Other studies have shown that heterosexual women often prefer men taller than they are rather than a man with above average height. While women usually desire men to be at least the same height as themselves or taller, several other factors also determine male attractiveness, and the male-taller norm is not universal. For example, taller women are more likely to relax the "taller male" norm than shorter women. Furthermore, professor Adam Eyre-Walker, from the University of Sussex, has stated that there is, as yet, no evidence that these preferences are evolutionary preferences, as opposed to merely cultural preferences. In a double-blind study by Graziano et al., it was found that, in person, using a sample of women of normal size, they were on average most attracted to men who were of medium height (5'9"- 5'11") and less attracted to both men of shorter height (5'5"- 5'7") and men of tallest height (6'2"- 6'4").

Additionally, women seem more receptive to an erect posture than men, though both prefer it as an element within beauty. According to one study (Yee N., 2002), gay men who identify as "Only Tops" tend to prefer shorter men, while gay men who identify as "Only Bottoms" tend to prefer taller men.

In romances in Middle English literature, all of the "ideal" male heroes are tall, and the vast majority of the "valiant" male heroes are tall too.

Hairiness

Studies based in the United States, New Zealand, and China have shown that women rate men with no trunk (chest and abdominal) hair as most attractive, and that attractiveness ratings decline as hairiness increases. Another study, however, found that moderate amounts of trunk hair on men was most attractive, to the sample of British and Sri Lankan women. Further, a degree of hirsuteness (hairiness) and a waist-to-shoulder ratio of 0.6 is often preferred when combined with a muscular physique.

In a study using Finnish women, women with hairy fathers were more likely to prefer hairy men, suggesting that preference for hairy men is either the result of genetics or imprinting. Among gay men, another study (Yee N., 2002) reported gay males who identify as "only tops" prefer less hairy men, while gay males who identify as "only bottoms" prefer hairier men.

Skin color

Testosterone has been shown to darken skin color in laboratory experiments. In his foreword to Peter Frost's 2005 Fair Women, Dark Men, University of Washington sociologist Pierre L. van den Berghe writes: "Although virtually all cultures express a marked preference for fair female skin, even those with little or no exposure to European imperialism, and even those whose members are heavily pigmented, many are indifferent to male pigmentation or even prefer men to be darker." Despite this, the aesthetics of skin tone varies from culture to culture. Manual laborers who spent extended periods of time outside developed a darker skin tone due to exposure to the sun. As a consequence, an association between dark skin and the lower classes developed. Light skin became an aesthetic ideal because it symbolized wealth. "Over time society attached various meanings to these colored differences. Including assumptions about a person's race, socioeconomic class, intelligence, and physical attractiveness."

According to one study (Yee N., 2002), gay men who identify as "Only Tops" tend to prefer lighter-skinned men while gay men who identify as "Only Bottoms" tend to prefer darker-skinned men.

More recent research has suggested that redder and yellower skin tones, reflecting higher levels of oxygenated blood, melanin pigment and net dietary intakes of fruit and vegetables, appears healthier, and therefore more attractive.

Female physical attractiveness

Research indicates that heterosexual men tend to be attracted to young and beautiful women with bodily symmetry. Rather than decreasing it, modernity has only increased the emphasis men place on women's looks. Evolutionary psychologists attribute such attraction to an evaluation of the fertility potential in a prospective mate.

Facial features

A University of Toronto study found that ideal facial proportions of Jessica Alba were close to the average of all female profiles.

Namie Amuro inspired the small-face fad in Japan which caused Japanese women to buy beauty products such as masks and creams to try to obtain a small face like hers.

See also: Cuteness and Averageness

Research has attempted to determine which facial features communicate attractiveness. Facial symmetry has been shown to be considered attractive in women, and men have been found to prefer full lips, high forehead, broad face, small chin, small nose, short and narrow jaw, high cheekbones, clear and smooth skin, and wide-set eyes. The shape of the face in terms of "how everything hangs together" is an important determinant of beauty. A University of Toronto study found correlations between facial measurements and attractiveness; researchers varied the distance between eyes, and between eyes and mouth, in different drawings of the same female face, and had the drawings evaluated; they found there were ideal proportions perceived as attractive (see photo). These proportions (46% and 36%) were close to the average of all female profiles. Women with thick, dark limbal rings in their eyes have also been found to be more attractive. The explanation given is that because the ring tends to fade with age and medical problems, a prominent limbal ring gives an honest indicator of youth.

In a cross-cultural study, more neotenized (i.e., youthful looking) female faces were found to be most attractive to men while less neotenized female faces were found to be less attractive to men, regardless of the females' actual age. One of these desired traits was a small jaw. In a study of Italian women who have won beauty competitions, it was found that their faces had more "babyish" (pedomorphic) traits than those of the "normal" women used as a reference.

The Japanese anime character design reflects men's general preference for women with neotenous features, such as large eyes, small noses and jaws, flat faces, large heads and short arms and legs.

In a cross-cultural study, Marcinkowska et al. said that 18- to 45-year-old heterosexual men in all 28 countries surveyed preferred photographs of 18- to 24-year-old Caucasian women whose faces were feminized using Psychomorph software over faces of 18- to 24-year-old Caucasian women that were masculinized using that software, but there were differences in preferences for femininity across countries. The higher the National Health Index of a country, the more were the feminized faces preferred over the masculinized faces. Among the countries surveyed, Japan had the highest femininity preference and Nepal had the lowest femininity preference.

Michael R. Cunningham of the Department of Psychology at the University of Louisville found, using a panel of East Asian, Hispanic and White judges, that the Asian, Hispanic and White female faces found most attractive were those that had "neonate large eyes, greater distance between eyes, and small noses" and his study led him to conclude that "large eyes" were the most "effective" of the "neonate cues". Cunningham also said that "shiny" hair may be indicative of "neonate vitality". Using a panel of blacks and whites as judges, Cunningham found more neotenous faces were perceived as having both higher "femininity" and "sociability". In contrast, Cunningham found that faces that were "low in neoteny" were judged as "intimidating". Cunningham noted a "difference" in the preferences of Asian and white judges with Asian judges preferring women with "less mature faces" and smaller mouths than the White judges. Cunningham hypothesized that this difference in preference may stem from "ethnocentrism" since "Asian faces possess those qualities", so Cunningham re-analyzed the data with "11 Asian targets excluded" and concluded that "ethnocentrism was not a primary determinant of Asian preferences." Rather than finding evidence for purely "neonate" faces being most appealing, Cunningham found faces with "sexually-mature" features at the "periphery" of the face combined with "neonate" features in the "center of the face" most appealing in men and women. Upon analyzing the results of his study, Cunningham concluded that preference for "neonate features may display the least cross-cultural variability" in terms of "attractiveness ratings" and, in another study, Cunningham concluded that there exists a large agreement on the characteristics of an attractive face.

In computer face averaging tests, women with averaged faces have been shown to be considered more attractive. This is possibly due to average features being more familiar and, therefore, more comfortable.

Commenting on the prevalence of whiteness in supposed beauty ideals in his book White Lies: Race and the Myth of Whiteness, Maurice Berger states that the schematic rendering in the idealized face of a study conducted with American subjects had "straight hair," "light skin," "almond-shaped eyes," "thin, arched eyebrows," "a long, thin nose, closely set and tiny nostrils" and "a large mouth and thin lips", though the author of the study stated that there was consistency between his results and those conducted on other races. Scholar Liu Jieyu says in the article White Collar Beauties, "The criterion of beauty is both arbitrary and gendered. The implicit consensus is that women who have fair skin and a slim figure with symmetrical facial features are pretty." He says that all of these requirements are socially constructed and force people to change themselves to fit these criteria.

One psychologist speculated there were two opposing principles of female beauty: prettiness and rarity. So on average, symmetrical features are one ideal, while unusual, stand-out features are another. A study performed by the University of Toronto found that the most attractive facial dimensions were those found in the average female face. However, that particular University of Toronto study looked only at white women.

A study that used Chinese, Malay and Indian judges said that Chinese women with orthognathism where the mouth is flat and in-line with the rest of the face were judged to be the most attractive and Chinese women with a protruding mandible where the jaw projects outward were judged to be the least attractive.

A 2011 study by Wilkins, Chan and Kaiser found correlations between perceived femininity and attractiveness, that is, women's faces which were seen as more feminine were judged by both men and women to be more attractive.

A component of the female beauty ideal in Persian literature is for women to have faces like a full moon.

In Arabian society in the Middle Ages, a component of the female beauty ideal was for women to have round faces which were like a "full moon".

In Japan, during the Edo period, a component of the female beauty ideal was for women to have long and narrow faces which were shaped like ovals.

In Jewish Rabbinic literature, the Rabbis considered full lips to be the ideal type of lips for women.

Genitalia

Evidence from various cultures suggests that gynephilic men tend to find the sight of women's genitalia to be sexually arousing.

Youthfulness

See also: Age disparity in sexual relationships

Cross-cultural data shows that the reproductive success of women is tied to their youth and physical attractiveness such as the pre-industrial Sami where the most reproductively successful women were 15 years younger than their man. One study covering 37 cultures showed that, on average, a woman was 2.5 years younger than her male partner, with the age difference in Nigeria and Zambia being at the far extreme of 6.5 to 7.5 years. As men age, they tend to seek a mate who is ever younger.

25% of eHarmony's male customers over the age of 50 request to only be matched with women younger than 40. A 2010 OkCupid study of 200,000 users found that female desirability to its male users peaks at age 21, and falls below the average for all women at 31. After age 26 men have a larger potential dating pool than women on the site; by 48 their pool is almost twice as large. The median 31-year-old male user searches for women aged 22 to 35, while the median 42-year-old male searches for women 27 to 45. The age skew is even greater with messages to other users; the median 30-year-old male messages teenage girls as often as women his own age, while mostly ignoring women a few years older than him. Excluding the most and least beautiful 10% of women, however, women's attractiveness does not change between 18 and 40.

Pheromones (detected by female hormone markers) reflects female fertility and the reproductive value mean. As females age, the estrogen-to-androgen production ratio changes and results in female faces to appear more and more masculine (thus appearing less "attractive"). In a small (n=148) study performed in the United States using male college students at one university, the mean age expressed as ideal for a wife was found to be 16.87 years old, while 17.76 was the mean ideal age for a brief sexual encounter; however, the study sets up a framework where "taboos against sex with young girls" are purposely diminished, and biased their sample by removing any participant over the age of 30, with a mean participant age of 19.83. In a study of penile tumescence, men were found most aroused by pictures of young adult females.

Breasts

Research has shown that most heterosexual men enjoy the sight of female breasts. Some studies indicate that men prefer large, firm breasts, while a contradictory study of British undergraduates found men preferring small breasts on women. Smaller breasts were widely associated with youthfulness. Cross-culturally, another study found "high variability" regarding the ideal breast size. Some researchers in the United Kingdom have speculated that a preference for larger breasts may have developed in Western societies because women with larger breasts tend to have higher levels of the hormones estradiol and progesterone, which both promote fertility.

A study showed that men prefer symmetrical breasts. Breast symmetry may be particularly sensitive to developmental disturbances and the symmetry differences for breasts are large compared to other body parts. Women who have more symmetrical breasts tend to have more children.

Literary conventions

Historical literature often includes specific features of individuals or a gender that are considered desirable. These have often become a matter of convention, and should be interpreted with caution. In Arabian society in the Middle Ages, a component of the female beauty ideal was for women to have small breasts. In Persian literature, beautiful women are said to have breasts like pomegranates or lemons. In the Chinese text "Jeweled Chamber Secrets" (Chinese: 玉 房 秘 訣) from the Six Dynasties period, the ideal woman was described as having firm breasts. In Sanskrit literature, beautiful women are often said to have breasts so large that they cause the women to bend a little bit from their weight. In Middle English literature, beautiful women should have small breasts that are round like an apple or a pear.

Buttocks

Main article: Cultural history of the buttocks

Biological anthropologist Helen B. Fisher of the Center for Human Evolution Studies in the Department of Anthropology of Rutgers University said that, "perhaps, the fleshy, rounded buttocks... attracted males during rear-entry intercourse." Bobbi S. Low et al. of the School of Natural Resources and Environment at the University of Michigan, said the female "buttocks evolved in the context of females competing for the attention and parental commitment of powerful resource-controlling males" as an "honest display of fat reserves" that could not be confused with another type of tissue, although T. M. Caro, professor in the Center for Population Biology and the Department of Wildlife, Fish, and Conservation Biology, at University of California, Davis, rejected that as being a necessary conclusion, stating that female fatty deposits on the hips improve "individual fitness of the female", regardless of sexual selection.

In a 1995 study, black men were more likely than white men to use the words "big" or "large" to describe their conception of an attractive woman's posterior.

Body mass

Body Mass Index (BMI) is an important determinant to the perception of beauty. Even though the Western ideal is for a thin woman, some cultures prefer plumper women, which has been argued to support that attraction for a particular BMI merely is a cultural artifact. The attraction for a proportionate body also influences an appeal for erect posture. One cross-cultural survey comparing body-mass preferences among 300 of the most thoroughly studied cultures in the world showed that 81% of cultures preferred a female body size that in English would be described as "plump".

Availability of food influences which female body size is attractive which may have evolutionary reasons. Societies with food scarcities prefer larger female body size than societies having plenty of food. In Western society males who are hungry prefer a larger female body size than they do when not hungry.

In the United States, women overestimate men's preferences for thinness in a mate. In one study, American women were asked to choose what their ideal build was and what they thought the build most attractive to men was. Women chose slimmer than average figures for both choices. When American men were independently asked to choose the female build most attractive to them, the men chose figures of average build. This indicates that women may be misled as to how thin men prefer women to be. Some speculate that thinness as a beauty standard is one way in which women judge each other and that thinness is viewed as prestigious for within-gender evaluations of other women. A reporter surmised that thinness is prized among women as a "sign of independence, strength and achievement." Some implicated the fashion industry for the promulgation of the notion of thinness as attractive.

East Asians have historically preferred women whose bodies had small features. For example, during the Spring and Autumn period of Chinese history, women in Chinese harems wanted to have a thin body in order to be attractive for the Chinese emperor. Later, during the Tang Dynasty, a less thin body type was seen as most attractive for Chinese women. In Arabian society in the Middle Ages, a component of the female beauty ideal was for women to be slender like a "cane" or a "twig". In the Chinese text "Jeweled Chamber Secrets" (Chinese: 玉 房 秘 訣) from the Six Dynasties period, the ideal woman was described as not being "large-boned".

In the Victorian era, women who adhered to Victorian ideals were expected to limit their food consumption to attain the ideal slim figure. In Middle English literature, "slender" women are considered beautiful.

Waist–hip ratio

Main article: Waist–hip ratio

Measurement of waist hip ratio: In a lean person (left), the waist can be measured at its narrowest point, while for a person with convex waist (right), it may be measured at about one inch above the navel. The hip is measured at its widest portion of the buttocks at left, and at the greater trochanters at right.

A WHR of 0.7 for women has been shown to correlate strongly with general health and fertility. Women within the 0.7 range have optimal levels of estrogen and are less susceptible to major diseases such as diabetes, heart disease, and ovarian cancers. Women with high WHR (0.80 or higher) have significantly lower pregnancy rates than women with lower WHRs (0.70–0.79), independent of their BMIs. Female waist-to-hip ratio (WHR) has been proposed by evolutionary psychologists to be an important component of human male mate choice, because this trait is thought to provide a reliable cue to a woman's reproductive value.

Both men and women judge women with smaller waist-to-hip ratios more attractive. Ethnic groups vary with regard to their ideal waist-to-hip ratio for women, ranging from 0.6 in China, to 0.8 or 0.9 in parts of South America and Africa, and divergent preferences based on ethnicity, rather than nationality, have also been noted. A study found the Machiguenga people, an isolated indigenous South American ethnic group, prefer women with high WHR (0.9). The preference for heavier women, has been interpreted to belong to societies where there is no risk of obesity.

In Chinese, the phrase "willow waist" (Chinese: 柳 腰) is used to denote a beautiful woman by describing her waist as being slender like a willow branch.

In the Victorian era, a small waist was considered the main trait of a beautiful woman.

Height

Most men tend to be taller than their female partner. It has been found that, in Western societies, most men prefer shorter women, although height is a more important factor for women when choosing a man than it is for a man choosing a woman. Men tend to view taller women as less attractive, and people view heterosexual couples where the woman is taller to be less ideal. Women who are 0.7 to 1.7 standard deviations below the mean female height have been reported to be the most reproductively successful, since fewer tall women get married compared to shorter women. However, in other ethnic groups, such as the Hadza, study has found that height is irrelevant in choosing a mate.

In Middle English literature, tallness is a characteristic of ideally beautiful women.

Leg-to-body ratio

This woman has long legs relative to her torso length.

A study using Polish participants by Sorokowski found 5% longer legs than average person leg to body ratio for both on man and woman was considered most attractive. The study concluded this preference might stem from the influence of leggy runway models. Another study using British and American participants, found "mid-ranging" leg-to-body ratios to be most ideal.

A study by Swami et al. of British male and female undergraduates showed a preference for men with legs as long as the rest of their body and women with 40% longer legs than the rest of their body. The researcher concluded that this preference might be influenced by American culture where long legged women are portrayed as more attractive.

Marco Bertamini criticized the Swami et al. study for using a picture of the same person with digitally altered leg lengths which he felt would make the modified image appear unrealistic. Bertamini also criticized the Swami study for only changing the leg length while keeping the arm length constant. After accounting for these concerns in his own study, Bertamini's study which used stick figures also found a preference for women with proportionately longer legs than men. When Bertamini investigated the issue of possible sexual dimorphism of leg length, he found two sources that indicated that men usually have slightly proportionately longer legs than women or that differences in leg length proportion may not exist between men and women. Following this review of existing literature on the subject, he conducted his own calculations using data from 1774 men and 2208 women. Using this data, he similarly found that men usually have slightly proportionately longer legs than women or that differences in leg length proportion may not exist between men and women. These findings made him rule out the possibility that a preference for women with proportionately longer legs than men is due proportionately longer legs being a secondary sex characteristic of women.

Feet size

According to some studies, most men prefer women with small feet, such as in ancient China where foot binding was practiced.

In Jewish Rabbinic literature, the Rabbis considered small feet to be the ideal type of feet for women.

Hair

Men have been found to prefer long-haired women. An evolutionary psychology explanation for this is that malnutrition and deficiencies in minerals and vitamins causes loss of hair or hair changes. Hair therefore indicates health and nutrition during the last 2–3 years. Lustrous hair is also often a cross-cultural preference.

One study reported non-Asian men to prefer blondes and Asian men to prefer black-haired women.

A component of the female beauty ideal in Persian literature is for women to have black hair, which was also preferred in Arabian society in the Middle Ages. In Middle English literature, curly hair is a necessary component of a beautiful woman.

Movement patterns

The way an individual moves can indicate health and even age and influence attractiveness. A study reflecting the views of 700 individuals and that involved animated representations of people walking, found that the physical attractiveness of women increased by about 50 percent when they walked with a hip sway. Similarly, the perceived attractiveness of males doubled when they moved with a swagger in their shoulders.

Skin tone and skin radiance

This painting was intended to "contrast a Caucasian with an African beauty". In the painting, the black woman represents the beauty of a black pearl and the white woman represents the beauty of a white pearl.

Main article: Human skin color § Social status and racism

A preference for lighter-skinned women has remained prevalent over time, even in cultures without European contact, though exceptions have been found. Anthropologist Peter Frost stated that since higher-ranking men were allowed to marry the perceived more attractive women, who tended to have fair skin, the upper classes of a society generally tended to develop a lighter complexion than the lower classes by sexual selection (see also Fisherian runaway). In contrast, one study on men of the Bikosso tribe in Cameroon found no preference for attractiveness of females based on lighter skin color, bringing into question the universality of earlier studies that had exclusively focused on skin color preferences among non-African populations.

Today, skin bleaching is not uncommon in parts of the world such as Africa, and a preference for lighter-skinned women generally holds true for African Americans, Latin Americans, and Asians. One exception to this has been in contemporary Western culture, where tanned skin used to be associated with the sun-exposed manual labor of the lower-class, but has generally been considered more attractive and healthier since the mid-20th century.

More recent work has extended skin color research beyond preferences for lightness, arguing that redder (higher a* in the CIELab colour space) and yellower (higher b*) skin has healthier appearance. These preferences have been attributed to higher levels of red oxygenated blood in the skin, which is associated with aerobic fitness and lack of cardiac and respiratory illnesses, and to higher levels of yellow-red antioxidant carotenoids in the skin, indicative of more fruit and vegetables in the diet and, possibly more efficient immune and reproductive systems.

Research has additionally shown that skin radiance or glowing skin indicates health, thus skin radiance influences perception of beauty and physical attractiveness.

Nose

In Persian literature, beautiful women are said to have noses like hazelnuts.

In Arabian society in the Middle Ages, a component of the female beauty ideal was for women to have straight and fine noses.

In Jewish Rabbinic literature, the Rabbis considered a delicate nose to be the ideal type of nose for women.

In Japan, during the Edo period, a component of the female beauty ideal was for women to have tall noses which were straight and not "too tall".

Eyes

A study where photographs of several women were manipulated (so that their faces would be shown with either the natural eye color of the model or with the other color) showed that, on average, brown-eyed men have no preference regarding eye color, but blue-eyed men prefer women of the same eye color.

Through the East Asian blepharoplasty cosmetic surgery procedure, Asian women can permanently alter the structure of their eyelid. Some people have argued that this alteration is done to resemble the structure of a Western eyelid while other people have argued that this is generally done solely as an improvement that "matches" an Asian face instead of being done to resemble the structure of a Western eyelid.

A study that investigated whether or not an eyelid crease makes Chinese-descent women more attractive using photo-manipulated photographs of young Chinese-descent women's eyes found that the "medium upper eyelid crease" was considered most attractive by all three groups of both sexes: white people, Chinese and Taiwanese nationals together as a group, and Taiwanese and Chinese Americans together as a group. Similarly, all three groups of both genders found the absence of an eye crease to be least attractive on Chinese women.

In the late sixteenth century, Japanese people considered epicanthic folds to be beautiful.

A study that used Russian, American, Brazilian, Aché, and Hiwi raters, found that the only strong distinguisher between men and women's faces was wider eyes relative to facial height for women, and this trait consistently predicted attractiveness ratings for women.

In Arabian society in the Middle Ages, a component of the female beauty ideal was for women to have dark black eyes which are large and long and in the shape of almonds. Furthermore, the eyes should be lustrous, and they should have long eyelashes.

A source written in 1823 said that a component of the Persian female beauty ideal was for women to have large eyes which are black in color. In Persian literature, beautiful women are said to have eyes that are shaped like almonds.

In Chinese, the phrase "lucent irises, lustrous teeth" (Chinese: 明 眸 皓 齒) is used to describe a beautiful woman with "clear eyes" and "well-aligned, white teeth", and the phrase "moth-feeler eyebrows" (Chinese: 蛾眉) is used to denote a beautiful woman by describing her eyebrows as being thin and arched like moth antennae. In the Chinese text "The Grotto of the Immortals" (Chinese: 遊 仙 窟) written during the Tang dynasty period, narrow eyes were the preferred type of eyes for women, and, in the Chinese text "Jeweled Chamber Secrets" (Chinese: 玉 房 秘 訣) from the Six Dynasties period, the ideal woman was described as having small eyes.

In Japan, during the Edo period, one piece of evidence, the appearance of the "formal wife" of Tokugawa Iesada as determined by "bone anthropologist" Suzuki Hisashi, indicates that large eyes were considered attractive for women, but, another piece of evidence, the 1813 Japanese text "Customs, Manners, and Fashions of the Capital" (Japanese: 都 風 俗 化 粧 伝), indicates that large eyes were not considered attractive for women.

Other determinants

There has been research suggesting that women at the "fertile stage" of the menstrual cycle appear more attractive to single unattached men, but it is not clear exactly how this process works. Another study comparing British and American subjects concluded that there is a correlation between intelligence and physical attraction. The study concluded that intelligence is a big factor in physical attractiveness, particularly in males.

Possible gender differences for preferences

For both men and women, there appear to be universal criteria of attractiveness both within and across cultures and ethnic groups. When considering long term relationships, some studies have concluded that men place a higher emphasis on physical attractiveness in a partner than women do. On the other hand, some studies have found little difference between men and women in terms of the weight they place on physical characteristics when they are choosing partners for short-term relationships, in particular with regard to their implicit, as opposed to explicitly articulated, preferences. Other recent studies continue to find sex differences for long-term relationships.

Bengali Bride exemplifying wedding day beauty.

Some evolutionary psychologists, including David Buss, have argued that this long-term relationship difference may be consequence of ancestral humans who selected partners based on secondary sexual characteristics, as well as general indicators of fitness which allowed for greater reproductive success as a result of higher fertility in those partners, although a male's ability to provide resources for offspring was likely signaled less by physical features. It is argued that the most prominent indicator of fertility in women is youth, while the traits in a man which enhance reproductive success are proxies for his ability to accrue resources and protect.

Studies have shown that women pay greater attention to physical traits than they do directly to earning capability or potential to commit, including muscularity, fitness and masculinity of features; the latter preference was observed to vary during a woman's period, with women preferring more masculine features during the late-follicular (fertile) phase of the menstrual cycle. Additionally, women process physical attractiveness differently, paying attention to both individual features and the aesthetic effect of the whole face. A 2003 study in the area concluded that heterosexual women are about equally aroused when viewing men or women. Heterosexual men were only aroused by women. This study verified arousal in the test subjects by connecting them to brain imaging devices. Notably, the same study reported arousal for women upon viewing animals mating.

It has been shown that women prefer men with a more masculine facial dimorphism during the fertile period of the menstrual cycle and men with a more feminine facial dimorphism during other parts of the cycle. This distinction supports the sexy son hypothesis, which posits that it is evolutionarily advantageous for women to select potential fathers who are more genetically attractive, rather than the best caregivers.

Bonnie Adrian's book, Framing the Bride, discusses the emphasis Taiwanese brides place on physical attractiveness for their wedding photographs. Globalization and western ideals of beauty have spread and have become more prevalent in Asian societies where brides go through hours of hair and makeup to "transform everyday women with their individual characteristics into generic look-alike beauties in three hours' time." These brides go through hours of makeup to transform themselves into socially constructed beauty.

According to strategic pluralism theory, men may have correspondingly evolved to pursue reproductive strategies that are contingent on their own physical attractiveness. More physically attractive men accrue reproductive benefits from spending more time seeking multiple mating partners and relatively less time investing in offspring. In contrast, the reproductive effort of physically less attractive men, who therefore will not have the same mating opportunities, is better allocated either to investing heavily in accruing resources, or investing in their mates and offspring and spending relatively less time seeking additional mates.

Facial similarity and racial bias

Several studies have suggested that people are generally attracted to people who look like them and they generally evaluate faces that exhibit features of their own ethnic or racial group as being more attractive. Although both men and women use children's "facial resemblance" to themselves in "attractiveness judgments," a greater percentage of women in one study (37% n=30) found hypothetical children whose faces were "self-morphs" of themselves as most attractive when compared to men (30% n=23). The more similar a judged person is toward the judging person, the more the former is liked. However, this effect can be reversed. This might depend on how attractiveness is conceptualized: similar members (compared to dissimilar ones) of the opposite sex are judged as more likable in a prosocial sense. Again, findings are more ambiguous when looking for the desiring, pleasure related component of attractiveness. This might be influenced by the measure one uses (subjective ratings can differ from the way one actually reacts) and by situational factors: while men usually prefer women whose face resembles their own, this effect can reverse under stress, when dissimilar females are preferred.

A study by R. E. Hall in 2008, which examined determinations of physical attractiveness by having subjects look at the faces of women, found that race was sometimes a factor in these evaluations. In 2011, two studies found evidence that the ethnicity of a face influenced how attractive it was judge to be. A 2014 study by Tsunokai, McGrath and Kavanagh based on data from a dating website, the authors cited race as a factor in dating preferences by Asian-American men, both homosexual and heterosexual.

Social effects

Perceptions of physical attractiveness contribute to generalized assumptions based on those attractions. Individuals assume that when someone is beautiful, then they have many other positive attributes that make the attractive person more likeable. This is also called the 'beautiful-is-good' effect. Across cultures, what is beautiful is assumed to be good; attractive people are assumed to be more extroverted, popular, and happy. This could lead to a self-fulfilling prophecy, as, from a young age, attractive people receive more attention that helps them develop these characteristics. In one study, beautiful people were found to be generally happier than less beautiful or plain people, perhaps because these outgoing personality traits are linked to happiness, or perhaps because beauty led to increased economic benefits which partially explained the increased happiness. In another study testing first impressions in 56 female and 17 male participants at University of British Columbia, personality traits of physically attractive people were identified more positively and more accurately than those who were less physically attractive. It was explained that people pay closer attention to those they find physically beautiful or attractive, and thus perceiving attractive individuals with greater distinctive accuracy. The study believes this accuracy to be subjective to the eye of the beholder. Recent results from the Wisconsin Longitudinal Study confirmed the positive link between psychological well-being and attractiveness (higher facial attractiveness, lower BMI) and also found the complementary negative association with distress/depression. Even though connections and confounds with other variables could not be excluded, the effects of attractiveness in this study were the same size as the ones for other demographic variables.

However, attractiveness varies by society; in ancient China foot binding was practiced by confining young girls' feet in tightly bound shoes to prevent the feet from growing to normal size causing the women to have an attractive "lotus gait". In England, women used to wear corsets that severely constricted their breathing and damaged vital internal organs, in order to achieve a visual effect of an exaggeratedly low Waist-to-Hip ratio.

People make judgments of physical attractiveness based on what they see, but also on what they know about the person. Specifically, perceptions of beauty are malleable such that information about the person's personality traits can influence one's assessment of another person's physical beauty. A 2007 study had participants first rate pictures for attractiveness. After doing distracting math problems, participants saw the pictures again, but with information about the person's personality. When participants learned that a person had positive personality characteristics (e.g., smart, funny, kind), that person was seen as more physically attractive. Conversely, a person with negative personality characteristics (e.g., materialistic, rude, untrustworthy) was seen as less physically attractive. This was true for both females and males. A person may be perceived as being more attractive if they are seen as part of a group of friends, rather than alone, according to one study.

Physical attractiveness can have various effects. A survey conducted by London Guildhall University of 11,000 people showed that those who subjectively describe themselves as physically attractive earn more income than others who would describe themselves as less attractive. People who described themselves as less attractive earned, on average, 13% less than those who described themselves as more attractive, while the penalty for being overweight was around 5%. According to further research done on the correlation between looks and earnings in men, the punishment for unattractiveness is greater than the benefits of being attractive. However, in women the punishment is found to be equal to the benefits. Another study suggests that more physically attractive people are significantly more likely on average to earn considerably higher wages. Differences in income due to attractiveness was much more pronounced for men rather than women, and held true for all ranges of income.

It is important to note that other factors such as self-confidence may explain or influence these findings as they are based on self-reported attractiveness as opposed to any sort of objective criteria; however, as one's self-confidence and self-esteem are largely learned from how one is regarded by his/her peers while maturing, even these considerations would suggest a significant role for physical appearance. One writer speculated that "the distress created in women by the spread of unattainable ideals of female beauty" might possibly be linked to increasing incidence of depression.

Many have asserted that certain advantages tend to come to those who are perceived as being more attractive, including the ability to get better jobs and promotions; receiving better treatment from authorities and the legal system; having more choices in romantic partners and, therefore, more power in relationships; and marrying into families with more money. Those who are attractive are treated and judged more positively than those who are considered unattractive, even by those who know them. Also, attractive individuals behave more positively than those who are unattractive. One study found that teachers tend to expect that children who are attractive are more intelligent, and are more likely to progress further in school. They also consider these students to be more popular. Voters choose political candidates who are more attractive over those who are less attractive. Men and women use physical attractiveness as a measure of how "good" another person is. In 1946, Soloman Asch coined the Implicit Personality Theory, meaning that the presence of one trait tends to imply the existence of other traits. This is also known as the halo effect. Research suggests that those who are physically attractive are thought to have more socially desirable personalities and lead better lives in general. This is also known as the "what-is-beautiful-is-good effect." Discrimination against or prejudice towards others based on their appearance is sometimes referred to as lookism.

Some researchers conclude that little difference exists between men and women in terms of sexual behavior. Other researchers disagree. Symmetrical men and women have a tendency to begin to have sexual intercourse at an earlier age, to have more sexual partners, to engage in a wider variety of sexual activities, and to have more one-night stands. They are also prone to infidelity and are more likely to have open relationships. Additionally, they have the most reproductive success. Therefore, their physical characteristics are most likely to be inherited by future generations.

Concern for improving physical attractiveness has led many persons to consider alternatives such as cosmetic surgery. It has led scientists working with related disciplines such as computer imaging and mathematics to conduct research to suggest ways to surgically alter a face in terms of distances between facial features, to make it closer to an ideal face with "agreed-upon standards of attractiveness", by using algorithms to suggest an alternative which still resembles the current face. One research study found that cosmetic surgery as a way to "boost earnings" was "not profitable in a monetary sense." Perhaps people try to look more beautiful because they think it would make them happier. However, research shows that physical attractiveness seems to only have a marginal effect on happiness.

See also

• Adornment
• Body proportions
• Averageness
• Koinophilia
• Body shape
• Erotic capital
• Female body shape
• Halo effect
• Human physical appearance
• Matching hypothesis
• Sexual attraction