Echoism, Facial Symmetry

Echoism is a theorised aspect of facial symmetry. Facial symmetry, is one element of bodily symmetry, including fluctuating asymmetry. Along with traits such as averageness and youthfulness it influences judgements of aesthetic traits of physical attractiveness and beauty , and is associated with fitness-linked traits including health, It is also hypothesized as a factor in both interpersonal attraction and interpersonal chemistry.
Health and physical attractiveness
Edler 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. 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.