Attraction, the science of beauty

Sexual attraction is attraction on the basis of sexual desire or the quality of arousing such interest. Sexual attractiveness or sex appeal refers to an individual's ability to attract the sexual or erotic interest of another person, and is a factor in sexual selection or mate choice. The attraction can be to the physical or other qualities or traits of a person, or to such qualities in the context in which they appear. The attraction may be to a person's looks or movements or to their voice or smell, besides other factors. The attraction may be enhanced by a person's adornments, clothing, perfume, hair style, and anything else which can attract the sexual interest of another person. It can also be influenced by individual genetic, psychological, or cultural factors, or to other, more amorphous qualities of the person. Sexual attraction is also a response to another person that depends on a combination of the person possessing the traits and also on the criteria of the person who is attracted. a person's sexual attractiveness is to a large extent a subjective measure dependent on another person's interest, perception, and sexual orientation.

To figure out how we pick mates, scientists have measured every shape and angle of the human face, studied the symmetry of dancers, crafted formulas from the measurements of Playboy models, and had both men and women rank attractiveness based on smelling armpit sweat. After all this and more, the rules of attraction for the human species are still not clearly understood. How it all factors into true love is even more mysterious.

But a short list of scientific rules for the game of love is emerging. Some are as clearly defined as the prominent, feminine eyes of a supermodel or the desirable hips of a well-built man. Other rules work at the subconscious level, motivating us to action for evolutionary reasons that are tucked inside clouds of infatuation.
Good symmetry shows that an individual has the genetic goods to survive development, is healthy, and is a good and fertile choice for mating. "It makes sense to use symmetry variation in mate choice," said evolutionary biologist Randy Thornhill of the University of New Mexico. "If you choose a perfectly symmetrical partner and reproduce with them, your offspring will have a better chance of being symmetric and able to deal with perturbations."

Thornhill has been studying symmetry for 15 years and scanned faces and bodies into computers to determine symmetry ratios. Both men and women rated symmetrical members of the opposite sex as more attractive and in better health than their less symmetrical counterparts. The differences can be just a few percent—perceivable though not necessarily noticeable.

By questioning the study participants, Thornhill also found that men with higher degrees of symmetry enjoy more sexual partners than men of lower symmetry.

Body shape is of course important, too. And scientists have some numbers to prove it. Psychologist Devendra Singh of the University of Texas studied people's waist-to-hip ratio (WHR).
In general, a range of 0.67 to 1.18 in females is attractive to men, Singh concluded in a 2004 study, while a 0.8 to 1.0 WHR in men is attractive to women, although having broad shoulders is more of a turn-on. What exactly is encoded in the hip ratio? A uniformed shape to whether the person will have enough energy to care for offspring.
Where fat is deposited on the body is determined by sex hormones; testosterone in men and estrogen in women. If a woman produces the proper amount and mixture of estrogen, then her WHR will naturally fall into the desired range. The same goes for a male's testosterone. People in the ideal hip-ratio range, regardless of weight, are less susceptible to disease such as cardiovascular disorders, cancer, and diabetes, studies have shown. Women in this range also have less difficulty conceiving, in this case beauty is conveying information about health and fertility.
Disregarding things like oxytocin as a chemical attractant, research found women both smell and look more attractive to men at certain times of the month. And symmetrical men smell better. Borrowing sweaty undershirts from a variety of men, Thornhill offered the shirts to the noses of women, asking for their impressions of the scents. Hands down, the women found the scent of a symmetrical man to be more attractive and desirable, especially if the woman was menstruating. Sex and romance may seem inextricably linked, but the human brain clearly distinguishes between the two, according to a new study. The upshot: Love is the more powerful emotion. 17 young men and women, all of whom had recently fallen madly in love. They filled out questionnaires while their brains were hooked up to a functional magnetic resonance imaging (fMRI) system. Romance seems to steep in parts of the brain that are rich in dopamine, a chemical known to affect emotions. These brain regions are also linked by other studies to the motivation for rewards.
The activation regions associated with intense romantic love were mostly on the right side of the brain, while the activation regions associated with facial attractiveness were mostly on the left.

Traditional wifely skills such as being a good cook are also becoming less important to modern men. In Western societies where men and women are equal, interest in a woman’s appearance is in decline. women will find it hard to believe, but new research suggests men increasingly value intellect and character in a partner over a shapely figure.
However, women now tend to be more interested in a man’s looks than before, and less preoccupied by their wealth as they are able to depend on themselves financially.
Dr Marcel Zentner, a psychologist at York University, said: ‘We found in societies like Britain, or especially in Scandinavia, men place increasing value on other qualities, like intelligence, rather than curvy figures or skill at cooking’.

But he added: ‘Traditionally, women prefer wealthy men who have an ability to invest resources in any children. 'What we found was that as women because more equal, this preference declines, but men’s looks become much more important.’ His team surveyed 12,000 people in more than 30 countries asking them to describe which traits they most valued in a potential partner. They tallied the results to the country’s ranking on gender equality, from the World Economic Forum’s Global Gender Gap Index which looks at educational opportunities, health and political empowerment. Those who scored the highest for gender inequality went for traditional evolutionary traits. Men went for cooking and a curvy figure, which indicates fertility, while women chose men who can provide materially for a family. But in the more equal societies, there was a change in attitude – contradicting the common view that our mate choices are ‘hard wired’ in our brains.
Western societies have not reversed towards a culture of trophy husbands and female bread-winners, there had been a noticeable ‘shift in emphasis, and these findings challenge the idea proposed by some evolutionary psychologists.  Gender differences in mate-preferences are determined by evolved adaptations that became biologically embedded in the male and female brain.

Increases in gender equality in the society around us can also change the way we think about the opposite sex. Men can relax about having to build up wealth, but may benefit from looking after their looks a little more. The Gender Gap Index, which covers 135 countries, shows Iceland is the best place to be a working woman. The UK is 16th - behind most of Europe but ahead of the US and Canada. The rules of attraction  still apply for most people using positive personality traits has a halo effect of people seeing the best in you rather then small negative points. Although sex equality has altered male and female perspective, where certain attractive qualities have reversed for both sexes. It appears that modern society maybe evolving our brain chemistry, if that's a good thing or not time will tell...