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Symmetry, especially facial symmetry, is one of a number of aesthetic traits, including averageness and youthfulness, associated with health, physical attractiveness and beauty of a person or non-human animal according to the authors of Facial Attractiveness: Gillian Rhodes, Leslie A. Zebrowitz.^[1] It is also hypothesized as a factor in both interpersonal attraction and interpersonal chemistry.

[edit] Health and physical attractiveness

Edler ^[2] cited research supporting the claim that bilateral symmetry is an important indicator of freedom from disease, and worthiness for mating. Facial asymmetries and minor physical anomalies begin to appear early in embryonic development, mainly the first trimester of pregnancy, and can be a sign of instability during this growth.^{[citation needed]} Fluctuating asymmetry (random differences between two sides, as opposed to the deliberate natural asymmetry in some animals) develop throughout the lifespan of the individual and is a sign of the phenotype being subjected to some levels of stress.

The ability to cope with these pressures is partly reflected in the levels of symmetry.^{[clarification needed]} A higher degree of symmetry indicates a better coping system for environmental factors.^{[citation needed]} While the visible signs of this may not be particularly apparent, it is thought that they have at least a subconscious effect on people's perception of their beauty. Zaidel et al.^[3] in an empirical study upholds the claim that facial symmetry may be critical for the appearance of health. Their study disputes, however, the beauty or attractiveness claim.

Facial symmetry is neither the only trait nor is it necessarily the most important trait of what a culture considers attractive. A competing aesthetic theory is wabi sabi. Characteristics of the wabi-sabi aesthetic include asymmetry, asperity, simplicity, modesty, intimacy, and suggest a natural process.

[edit] Interpersonal attraction

Suzi Malin, a British portrait painter, wrote Love at First Sight (ISBN 0-7566-0401-X) to examine the relationships of 50 celebrity couples. She speculates that there are three aspects of facial symmetry which attract one person to another: echoism, harmonism and prima copulism. Echoism is the similarity of one or more facial features, particularly the eyes, eyebrows, nose and mouth. Harmonism is a similarity in facial proportions, usually involving the features and the distance between them. Prima copulism is an attraction to another person based on them having similar features to someone with whom they formed a strong interpersonal bond with at an early age, usually a mother or father.^{[citation needed]}

In "Symmetry and Human Facial Attractiveness" (University of St Andrews 1999) by David I. Perrett, D. Michael Burta, Ian S. Penton-Voaka, Kieran J. Leea, Duncan A. Rowlanda and Rachel Edwards it is posited again that symmetry may act as a marker of phenotypic and genetic quality and is preferred during mate selection in a variety of species. Measures of human body symmetry correlate with attractiveness, but studies manipulating human face images report a preference for asymmetry. These results may reflect unnatural feature shapes and changes in skin textures introduced by image processing. When the shape of facial features is varied (with skin textures held constant), increasing symmetry of face shape increases ratings of attractiveness for both male and female faces. These findings imply facial symmetry may have a positive impact on mate selection in humans. This, and other recent scientific findings, have been tested empirically on perceived "beautiful people" in Hollywood and researchers found that on a percentage basis the highest rating of symmetry was achieved by actress Cate Blanchett.^{[citation needed]}

[edit] Historical perspective

This normative study of the bone structure of the face and skull places it in the intellectual traditions of Phrenology and Craniometry.^{[citation needed]} These earlier traditions ambitiously sought to assess character, personality, or intelligence from a person's bone structure.^{[citation needed]}

Since the 1990s, descriptive studies of human facial bone structure underlie the practice of face recognition systems using software for security applications. The reliability of these systems has been brought into question.^{[citation needed]}

[edit] References

• Edler, RJ. June 2001. "Background Considerations to Facial Aesthetics". "Sexual reproduction and parasite resistance" section retrieved 31 May 2005.
• Fink, B; Manning, JT; Neave, N; Grammer, K. "Second to fourth digit ratio and facial asymmetry". "Introduction" section retrieved 31 May 2005.

[edit] Footnotes

1. ^ Rhodes, Gillian; Zebrowitz, Leslie, A. (2002). Facial Attractiveness - Evolutionary, Cognitive, and Social Perspectives. Ablex. ISBN 1567506364. 
2. ^ Edler R. J. "Background Considerations to Facial Aesthetics", (British) Journal of Orthodontics, Vol. 28, No. 2, June 2001, pp. 159-168.
3. ^ Zaidel D. W., Aarde S. M., and Baig, K. "Appearance of symmetry, beauty, and health in human faces", Brain and Cognition 57(3):(2005) pp. 261-263.

[edit] Further reading

• Fink, B. & Grammer, K. & Thornhill, R. (2001). Human (Homo sapiens) facial attractiveness in relation to skin texture and color. Journal of Comparative Psychology, 115(1), 92-99. Full text

• Johnston, V.S., Hagel, R., Franklin, M., Fink, B. & Grammer, K. (2001). Male facial attractiveness: Evidence for hormone mediated adaptive design. Evolution and Human Behavior, 22(4), 251-267. Full text

[edit] External links

• "Appearance of symmetry, beauty, and health in human faces" -- link to article by Zaidel et al.
• "Teeth, Beauty, Biology, and Health" – a class handout on dentition and facial symmetry at the College of Dentistry – University of Illinois at Chicago.
• "Chimeric Face Experiment" – Perform a facial symmetry and attractiveness experiment by uploading a photo
• FaceResearch – Online studies on facial symmetry by researchers affiliated with University of Aberdeen (Scotland) School of Psychology, and University of St. Andrews (Scotland).
• "Background Consideration to Facial Aesthetics" -- link to article by R. J. Edler.