August 10, 2012

Lack of sexual dimorphism in facial proportions in White European faces

A quick observation on methodology: facial height was measured using the top of the upper lip as a landmark. But, it may be the case that upper lip height is sexually dimorphic (pdf; DOI 10.1007/s10508-006-9136-1).

PLoS ONE 7(8): e42705. doi:10.1371/journal.pone.0042705

A Lack of Sexual Dimorphism in Width-to-Height Ratio in White European Faces Using 2D Photographs, 3D Scans, and Anthropometry

Robin S. S. Kramer et al.

Facial width-to-height ratio has received a great deal of attention in recent research. Evidence from human skulls suggests that males have a larger relative facial width than females, and that this sexual dimorphism is an honest signal of masculinity, aggression, and related traits. However, evidence that this measure is sexually dimorphic in faces, rather than skulls, is surprisingly weak. We therefore investigated facial width-to-height ratio in three White European samples using three different methods of measurement: 2D photographs, 3D scans, and anthropometry. By measuring the same individuals with multiple methods, we demonstrated high agreement across all measures. However, we found no evidence of sexual dimorphism in the face. In our third study, we also found a link between facial width-to-height ratio and body mass index for both males and females, although this relationship did not account for the lack of dimorphism in our sample. While we showed sufficient power to detect differences between male and female width-to-height ratio, our results failed to support the general hypothesis of sexual dimorphism in the face.



princenuadha said...

I thought that's how it should be, given that one ratio might be considered most beautiful.

Jim said...

I don't have the background to make much sense of the paper, so correct me if I get this wrong, but the first photograph shows them measuring across the guy's cheekbones, (Is that the standard method?) when what is sexually dimorphically male about his face is his big wide chin. He would never be a very convincing drag queen.

Another feature that is characteristally male in Western Europeans is a square chin, although not only Europeans - I once saw a Hakka guy with the same feature. It made him look very norhhtern. I have seen this feature on some women, but attenuated, and as I saw on some non-Europeans. Does this method of skull measurement take that into account?