Altruistic Face: Experimental Study on Facial Morphology and Prosociality in Buryats of Southern Siberia

Abstract

The aim of the present experimental study was to investigate possible associations between indi - vidual cooperativeness and facial morphology. Participants of the study were Buryats of Southern Si - beria (males: N=98; females: N=89; mean age 20 ± 2y.). Individual cooperativeness was assessed in experimental economic game “Public Goods Game”, which was conducted “face-to-face”, in groups of 4 same-sex individuals, who were strangers to each other. The game involved real monetary pay-offs. In the course of the experiment such individual behavioral features as propensity for unconditional/conditional cooperation, selfishness, or free-riding were revealed. Facial shapes of participants were explored through anthropological photographs using geometric morphometrics, and via assessing standard facial indexes. As a result the relationship between facial shape and unconditional cooperation was identified and visualized. This relationship appeared only among males. The analysis of sex-specific facial traits of Buryats revealed that faces of male unconditional cooperators combined both male-specific, and female-specific facial features. This is the first study to investigate association between full facial shape and human cooperativeness.