You may find it hard to argue against, or even to begin arguing for, the line of reasoning in this study. It shows how a people’s capacity to make moral judgments is related to the relative lengths of two of their fingers:
“Testosterone administration modulates moral judgments depending on second-to-fourth digit ratio,” Estrella R. Montoya, David Terburg, Peter A. Bos, Geert-Jan Will, Vincent Buskens, Werner Raub, Jack van Honk [pictured right with his fingers are not visible, and below with some fingers visible], Psychoneuroendocrinology, epub January 2, 2013. The authors, at Utrecht University, Leiden University, and the University of Cape Town, explain:
“Recent testosterone administration studies show effects on cognitive empathy and social cooperation, which depend on right-hand’s second-to-fourth (2D:4D) digit ratio… Subjects who show an increase in utilitarian judgments following testosterone administration have significantly higher than average 2D:4D… while subjects showing more deontological judgments following testosterone administration have near-significantly lower 2D:4D…”
BONUS: Finger ratios don’t always predict body odor