Quantification and Preference of Facial Asymmetry of the Sub- Saharan Africans' 3D Facial Models

A substantial body of literature have reported findings on facial symmetry and asymmetry and their role in human mate choice. However, major gaps persist, with nearly all data originating from the WEIRD (Western, Educated, Industrialized, Rich and Developed) populations, and results remaining largely equivocal when compared across studies. The present study aimed at quantifying facial asymmetry from the 3D faces of the Hausa ethnic group of northern Nigeria and aimed at determining their perceptions and judgements of standardized facial images with different levels of asymmetry through rating. Ethical approval to scan the faces of the subjects was given by the University College London and Federal Ministry of Health, Nigeria. Data were analyzed using R-studio software and results indicated that males were 12% (0.35mm) & 15% (0.23mm) more asymmetric in the face and eye respectively than females (Face: 0.3mm & Eye: 0.20mm). Additionally, individual 3D facial scans with lower levels of facial asymmetry (near facial symmetry) were perceived as more attractive, more suitable as spouses and more caring, whereas those with higher levels of facial asymmetry were perceived as more aggressive. The study conclusively asserted that all faces are asymmetric and the preference for less asymmetric faces was not just dependent on single facial trait, but rather on multiple facial traits; thus the study suggests that physical attractiveness is not just an arbitrary social construct, but at least, in part, a clue to overall health and a possible pointer to environmental influence.

Key Words: Sub-Saharan African's facial asymmetry, Quantification of facial asymmetry, Preference of asymmetry of 3D face models