The characterization of a person as “beautiful”, whether on an individual basis or by community consensus, is often based on some combination of inner beauty, which includes psychological factors such as personality, intelligence, grace, politeness, charisma, integrity, congruence and elegance, and outer beauty (i.e. physical attractiveness) which includes physical attributes which are valued on a subjective basis.
Standards of beauty have changed over time, based on changing cultural values. Historically, paintings show a wide range of different standards for beauty. However, humans who are relatively young, with smooth skin, well-proportioned bodies, and regular features, have traditionally been considered the most beautiful throughout history.
A strong indicator of physical beauty is "averageness", or "koinophilia". When images of human faces are averaged together to form a composite image, they become progressively closer to the "ideal" image and are perceived as more attractive. This was first noticed in 1883, when Francis Galton, cousin of Charles Darwin, overlaid photographic composite images of the faces of vegetarians and criminals to see if there was a typical facial appearance for each. When doing this, he noticed that the composite images were more attractive compared to any of the individual images.
Researchers have replicated the result under more controlled conditions and found that the computer generated, mathematical average of a series of faces is rated more favorably than individual faces. Evolutionarily, it makes logical sense that sexual creatures should be attracted to mates who possess predominantly common or average features.
A feature of beautiful women that has been explored by researchers is a waist–hip ratio of approximately 0.70. Physiologists have shown that women with hourglass figures are more fertile than other women due to higher levels of certain female hormones, a fact that may subconsciously condition males choosing mates.
People are influenced by the images they see in the media to determine what is or is not beautiful. Some feminists and doctors have suggested that the very thin models featured in magazines promote eating disorders, and others have argued that the predominance of white women featured in movies and advertising leads to a Eurocentric concept of beauty, feelings of inferiority in women of colour, and internalized racism.
The black is beautiful cultural movement sought to dispel this notion. Mixed race children are sometimes said to be more attractive than their parents because their genetic diversity arguably protects them from the inherited errors of their individual parents.