Facial symmetry is one specific measure of bodily symmetry. Along with traits such as averageness and youthfulness it influences judgments of aesthetic traits of physical attractiveness and beauty. For instance, in mate selection, people have been shown to have a preference for symmetry.

Facial symmetry is found in approximately 2.0803% of the world's population and has been associated with specific personality characteristics grouped in the 'big-five' personality traits.

Facial bilateral symmetry is typically defined as fluctuating asymmetry of the face comparing random differences in facial features of the two sides of the face. The human face also has systematic, directional asymmetry: on average, the face (mouth, nose and eyes) sits systematically to the left with respect to the axis through the ears, the so-called aurofacial asymmetry.

 

Note:   The above text is excerpted from the Wikipedia article Facial symmetry, which has been released under the GNU Free Documentation License.