The relationship between facial shape asymmetry and attractiveness in Mexican students

Abstract

Asymmetry was a prevalent feature in the present sample, and preferences for symmetric faces were not operating in the studied population.

Facial asymmetry and genetic ancestry inLatinAmerican admixed populations

“…Unfortunately, our data are not appropriate to test the hypothesis of DA as a proxy to developmental instability, but it is interesting to note how DA and FA leveis differ among ancestral groups (e.g., among individuais carrying high percentage of European, Amerindian, or African ancestry). This could he indicative that the hasal condition for any given population is not perfect symmetry, but some varying levei of both, DA and FA (Farrera et al, 2014).…”

“…Another important aspect when dealing with comparisons among DA and FA is that, usually, it is assumed that the "normal" expectance, or optimal phenotype for a population is FA = O or perfect symmetry, which is not necessarily a strong null hypothesis as David (2001) argues andFarrera et al (2014) suggest for a sample of Mexicans.…”

Analyzing Fluctuating Asymmetry with Geometric Morphometrics: Concepts, Methods, and Applications

“…A few studies of shape in Drosophila found no significant directional asymmetry of wing shape [115][116][117][118][119] or mixed results [120][121][122][123][124][125][126], although a series of other studies did find it [15,16,54,56,62,77,85,123]. Similarly, one study on human skulls [127] found no directional asymmetry of shape, whereas several others reported directional asymmetry of the skull [47,68,84,86,90,94,109] and soft tissues of the face and ears [38,66,98,104,105,108]. Further non-significant results were reported from mites [128] and wings of Trichogramma egg parasitoids [129]-but both studies reported results only from relatively small subsamples (≤30 specimens per sample) and tiny organisms, raising questions about statistical power and possible artifacts from mounting very small specimens.…”

“…In a study using a large combined sample from different Latin American countries, several factors were correlated to facial asymmetry: the strongest correlation was with age, but ethnic ancestry, heterozygosity, body mass index and height, as well as sex also had appreciable and significant effects [108]. Several studies have examined whether facial asymmetry is related to whether faces are rated as attractive by the subjects themselves or by other viewers, and some found a significant association [57,249,295,374], whereas others found no association [102,105] or a weak association only for male but not female faces [247]. Some analyses showed an association between fluctuating asymmetry and facial femininity or masculinity in humans [375], but others did not [102,374], nor was there a correlation between femininity or masculinity of skull shape and fluctuating asymmetry in baboons, chimpanzees, and gorillas [110].…”

“…To separate the two effects, it is possible to subtract the mean asymmetry to remove the effect of directional asymmetry before computing the Procrustes distance between the left and right shapes, so that the resulting distance indicates exclusively the magnitude of fluctuating asymmetry [11,41,239]. This measure of asymmetry, again, is available for both matching symmetry, where it is obtained from differences between the left and right sides [40,61,250,251], and for object symmetry, where it quantifies differences between original and reflected and relabeled configurations [86,94,102,105,134,148,252].…”