Sexually Dimorphic Faciometrics in Black Racial Groups From Early Adulthood to Late Middle Age.

An increasing body of research focusing on gender-related traits has utilized faciometrics in order to consider sexual dimorphism: Aspects as diverse as social heuristics, facial attractiveness, sexual orientation, aggression, and trustworthiness have all been investigated. However, the majority of these studies have tended to focus on White or Caucasian student populations and have paid little regard to either older populations or racial background. The current study therefore investigated sexual dimorphism in 450 participants (225 women) from a Black population across four age groups (20s, 30s, 40s, and 50s). In line with much previous research using White or Caucasian faces, the expected sexual dimorphism was seen in the younger age-group in three of the four indices (cheekbone prominence, facial width to lower facial height, and lower face height to full face height). However, consistent with more recent literature, the facial width to height ratio (fWHR) was not found to be significantly different between men and women in this age-group. Contrary to previous research, when considering broader age groups, the three established measures of facial sexual dimorphism, when looked at independently, remained static over time, but this was not true for fWHR. It is concluded that facial structure does not follow the same aging trajectory in all populations and care should be taken in choice of facial metric, depending on the nature of the sample under investigation.