Evolutionary psychologists and biologists have shown that
some morphological features are related to surprising behavioral
differences. One example of this is the length of the index finger
as compared with the ring finger, which is considered to be a
morphological index of prenatal exposure to testosterone in
animals and humans. We have compared here this finger-length
ratio, aggression and dominance in men and women, and results
show that men have a lower ratio than women, as well as higher
physical and verbal aggression, and higher aggressive and
sociable dominance. Moreover, this finger-length ratio negatively
correlates with physical aggression in men but not in women.
