New research on men’s index vs ringer-finger length is revealing
We can pretty much guarantee that as soon as you read this, you start comparing your index finger to your ring finger. The ratio of the length of the second finger, or digit, to the fourth finger (2D:4D) is influenced by fetal exposure to androgens; a smaller ratio indicates greater androgen exposure—i.e. more male hormones, chiefly testosterone.
Men with short index fingers and long ring fingers (smaller digit ratios) are on average nicer towards women, and this unexpected phenomenon stems from the hormones these men have been exposed to in their mother’s womb, according to a new study by researchers at McGill University.
“When with women, men with smaller ratios were more likely to listen attentively, smile and laugh, compromise or compliment the other person,” says Debbie Moskowitz, lead author and Professor of Psychology at McGill. They acted that way with partners, female friends, and colleagues. However, the 2D:4D ratio in women does not influence their social behavior.
An extra tidbit: a previous study found that men with smaller digit ratios have more children. “Our research suggests they have more harmonious relationships with women; these behaviors support the formation and maintenance of relationships with women,” Moskowitz says. “This might explain why they have more children on average.”