Perception of beauty can be affected by ingrained evolutionary factors, media influences, and individual personalities. Research indicates that formulas were used as early as Plato's time to define universal attractiveness. While more modern research supports the theory that certain features may represent genetic strength, making those who possess them appear more attractive, other factors can alter our perception of beauty. These include the media and the images a culture puts forth to represent physical perfection. Personality traits, such as kindness, sense of humor, and intelligence, may also impact the way we gauge attractiveness while interacting with others.
Ancient philosophers, including Plato, concluded that human perception of beauty was based on formulas that measured facial proportions. Modern research has expanded upon this theory, and results indicate that facial symmetry is usually a solid measure of beauty. Subjects rated as attractive in studies generally have features that are proportionate in size and shape when an imaginary line is drawn down the center of the face. Symmetry has been noted as an attractant in some species of animals and birds, and it is thought that symmetry generally represents strong and healthy genes.
Body proportions also play a role in perception of beauty, as humans are naturally inclined to look for a mate that appears to be robust and virile. Many cultures perceive beauty in the female body when the subject has a smaller waist and larger hips, as this body type has been thought to be less prone to infertility and other health issues. Ideal male forms are generally large and muscular, as these were thought to be better able to provide food and protection. Although modern health care advances and conveniences nullify the reasoning behind these perceptions of beauty, they remain as part of natural human instinct.
Cultural images representing beauty can add to, and sometimes alter, humans' natural perception of attractiveness. Enhancements, such as jewelry, makeup, and decorative clothing, may redefine beauty according to standards perpetuated by the media, or other standards that exist within certain cultures. In extreme cases, plastic surgery or bodily mutilation may be used achieve physical traits that are perceived as beautiful, but are not naturally present in all individuals.
Studies indicate that perception of beauty can be strongly influenced when the subject's personality and background are also considered. A subject with a charming personality may be rated as more attractive when the study is based on perception after a face-to-face discussion, rather than just viewing an image. A person's financial success, social popularity, and intelligence can also alter the way others perceive them, sometimes virtually eliminating physical standards of beauty.