Neither Facial Aggressiveness nor Facial Width to Height Ratio Are Related to Fighting Success

Richardson, Thomas, Anam Bhutta, Elena Bantoft, and R. Tucker Gilman. 2021. “Neither Facial Aggressiveness nor Facial Width to Height Ratio Are Related to Fighting Success.” PsyArXiv. April 14. doi:10.31234/osf.io/8zu6h

Abstract: There is a growing consensus that there is information in a man’s faces about how formidable (big and strong) he is. Recent work in mixed martial artists has shown that there may be facial correlates of fighting success. Fighters with more aggressive looking faces, as well as higher facial width to height ratios (fWHR), win a greater percentage of their fights. This has been used as evidence that human males may have evolved to signal and detect formidability using facial features. However, all previous studies have used datasets that may have considerable overlap, so it is important to replicate these effects in new samples. Moreover, some studies show that facial width to height ratio is correlated with body size, which may have confounded associations between fWHR and fighting success. The present study attempted to replicate and expand previous findings in 3 samples totalling several hundred professional fighters taken from several combat sporting leagues. I also tested whether head tilt affected ratings of aggressiveness, as previous studies have found conflicting effects. Overall, I found no significant links between fighting success and fWHR or facial aggressiveness. Tilting the head up or down both made a fighter’s face look more aggressive. Interestingly, there was only low-moderate agreement between raters on the apparent aggressiveness of a given face. Further, I found that facial width to height ratio was related to body size, and that body size mediated the link between fWHR and perceived aggression. This work casts doubt on several theories that argue the human face evolved to show fighting prowess and threat.