Finger length and altruism

Social scientists interested in the biological origins of human behavior have a strange obsession with finger length, and specifically with the ratio of second to fourth digit. Indeed, this ratio is an indicator to exposure to some hormones as an embryo, and any relation between this ratio and behavioral traits is a good hint that one is born with some behavioral variation. I have reported previously about entrepreneurship and risk taking in this regard, now it the turn of altruism.

Pablo Brañas-Garza, Jaromír Kovarík and Levent Neyse find that people with particularly high or low ratios are less altruistic than the norm. So, it seems that maximizing altruism is a delicate biological process, and that altruism is at least in part determined before birth. I am not sure where this paper leads us to next.