While there has been much emphasis on the objective properties of beautiful faces, some theories of physical attractiveness implicate norm-based coding of faces and experience-dependent preferences (e.g., Langlois & Roggman, 1990; Rhodes, Jeffery,Watson, Clifford, & Nakayama, 2003)
Taller raters created faces with larger ratios of forehead height to chin height-resulting in a larger forehead and a smaller chin, presumably caused by their biased exposure to faces from above eye level. Faces produced by shorter raters had a smaller forehead and a larger chin.
Mate choice is a complicated problem faced by our ancestors and assessment of different aspects of quality in a partner may involve specialised mechanisms. Fodor (1983) famously described the human brain as modular and has also argued that there is no continuity from perception to cognition (i.e., low level visual processes do not interact with higher cognitive processes). Potentially a modular nature is why it is so difficult to articulate the specific features that make faces attractive.
Although we can say whether a face is attractive or unattractive it is extremely difficult to articulate the specific features that determine this attraction. Evolutionary theorists have long posited special brain mechanisms that are focused on particular adaptive problems (Cosmides and Tooby 1994; Pinker1997).
Experts believe chemicals in the brain can explain why we find lasting love with some people and not others.
According to the study by renowned biological anthropologist Dr Helen Fisher, who has studied the science of romance for 35 years, it's all to do with which of four chemicals are dominant.
She said these chemicals create four personality types and finding the right match can lead to lifelong love.
Knowing the cognitive mechanisms undergirding the relations between judgments of attractiveness and body cues is essential to understanding human evolution, Tassinary notes. For example, physical manifestations of “femaleness” differ across cultures. Western cultures may favor a smaller waist-to-hip ratio (the “hourglass” figure), while certain non-Western cultures have been found that favor a larger ratio (the “tubular” figure).
"We have found that women evaluate facial attractiveness on two levels -- a sexual level, based on specific facial features like the jawbone, cheekbone and lips, and a nonsexual level based on overall aesthetics," said Robert G. Franklin, graduate student in psychology working with Reginald Adams, assistant professor of psychology and neurology, Penn State. "At the most basic sexual level, attractiveness represents a quality that should increase reproductive potential, like fertility or health."
On the nonsexual side, attractiveness can be perceived on the whole, where brains judge beauty based on the sum of the parts they see.