1. In this study, high altruism is posited as being ideal in social terms:
"the findings suggest that there might be an optimal level of exposure to these hormones from social perspective."(Branas-Garza, Pablo, Jaromír Kovářík, and Levent Neyse. "Second-to-fourth digit ratio has a non-monotonic impact on altruism." PloS one 8.4 (2013): e60419.)
The findings were that both a high and a low 2D:4D digit ratio (as compared to a median one) are correlated with low altruism in the Dictator Game. The study suggests that the median digit ratio corresponds to the optimal level of altruism, namely high altruism.
