Recent research on the relationships between perceptions of faces and social decision making has found that  the facial width of men is related to how trustworthiness they seem as well as how trustworthy their decisions actually are. In small groups wider faced men are more likely to exploit others for personal gain (Psychological Science, 2010). unless they perceive their group to be in competition with another group, then wider faced men are more cooperative than other men (Psychological Science, 2012). Wider faced men are also less likely to die as a result of contact violence (Evolution and Human Behavior, 2012).

Stirrat, M., & Perrett, D. I. (2012). Face structure predicts cooperation: men with wider faces are more generous to their in-group when out-group competition is salient. Psychological Science, 23(7), 718-722. doi:10.1177/0956797611435133

Stirrat, M., Stulp, G., & Pollet, T. V. (2012). Male facial width is associated with death by contact violence: Narrow-faced males are more likely to die from contact violence. Evolution and Human Behavior. published online 19 April, 2012. doi: 10.1016/j.evolhumbehav.2012.02.002

Stirrat, M, and Perrett, D I. Valid facial cues to cooperation and trust: Male facial width and trustworthiness. Psychological Science 21(3) 349-354 (2010). doi: 10.1177/0956797610362647