How the length of our fingers points to our parents’ income

Do wealthy mothers unknowingly give their sons the upper hand?
2D:4D ratio
Credit: Professor John Manning, Swansea University.

The ratio of a child’s index and ring fingers goes hand in hand with their family’s earnings, a major study suggests, owing to an unconscious evolutionary influence in utero.

Known as the Trivers–Willard hypothesis, it posits that women prenatally adjust their sex hormones to invest in either daughters or sons depending on maternal status, meaning poorer mothers will focus on feminising their fetuses while wealthier mothers will androgenise their children.