Previous studies have shown that facial width-to-height ratio (fWHR) is associated with sport performance, aggression and homicide. It has, however, been argued that the effect of fWHR might be a by-product of associations between size and behavioural measures.
Here we tested whether fWHR and body measures are associated with perceived aggressiveness, fighting ability and success in physical confrontation in Mixed Martial Arts (MMA) fighters. Although perceived fighting ability was predicted by weight but not by fWHR, both fWHR and body weight independently predicted perceived aggressiveness.
Furthermore, we found positive associations between fWHR and fighting performance, which appear independent of any effects of body size. Our results indicate that fWHR, as a testosterone-related morphological feature, is associated with fighting ability and perceived aggression, independently of body size, and that fWHR might therefore be considered a viable and reliable marker for inference of success in male intra-sexual competition.