Kalology is the study of beauty and the ways that beauty influences society. This study focuses primarily on human attractiveness, rather than the broader field of aesthetics, and was popularized during the 19th century when philosophers attempted to codify beauty and create a uniform system for evaluating it. A scale was even proposed, probably in jest, rating beauty in terms of the theoretical beauty of Helen of Troy, who supposedly had "a face to launch 1,000 ships."
Much of kalology is linked to psychology, although it is also a topic of interest among anthropologists. Psychologists are interested in what makes people "beautiful." They don't just look at physical features, but also properties like symmetry, proportions of various areas of the body, like the waist and hips, etc. Researchers have noted that certain features seem to be universally accepted as beautiful; Symmetry, for example, is highly prized. Some kalology researchers have suggested that being attracted to traits that suggest fertility or robustness may be hardwired into the human brain.
Anthropology comes into play as people examine beauty standards across cultures and within highly mixed societies and cultures. For example, complexion is often an important measure of beauty. Many cultures praise specific areas of skin tones, denying that others are not beautiful enough. This can be a source of social tension and conflict. In the United States, for example, where fair skin has historically been prized, some people with darker skin have used skin-lightening products in an attempt to get closer to the Caucasian ideal, despite the fact that many of these products are harmful. Weight is another common criterion used when evaluating beauty, and this ideal is also highly variable, depending on where you are in the world.
Kalologists also study works of art. Artworks often depict men and women believed to be beautiful by their peers, and artists presumably enhanced their subjects in some way to receive praise for their work. Examining portraits through the lens of calology can provide insight into historical beliefs about beauty, as well as providing information about the people who lived when these works were painted.
The human relationship with beauty is fascinating. Humans have been celebrating people they see as unusually beautiful for centuries. If reports are to be believed, beauty toppled empires, sparked wars, and ruined lives large and small, as well as bringing immeasurable happiness to some members of society. Understanding the human relationship with beauty and the history of beauty and aesthetics through the pursuit of callology can provide insights into the nature of humans as a whole.