The length of your fingers could provide clues to your sexuality, according to a study published in the journal Archives of Sexual Behavior.
In women, the index (second) finger and ring (fourth) fingers are typically of similar length, while in men there is usually a greater difference between the two (shorter index fingers and longer ring fingers).
Previous studies have suggested that there may be a link between prenatal hormone levels and differences in finger length, with those exposed to higher levels of the hormone testosterone more likely to have “male-typical hands”. In the womb, both males and females are exposed to testosterone.
For their research, a team from the University of Essex in the U.K. examined sets of identical twins (14 male and 18 female) with different sexualities, finding differences in their hands.
Among the female twins, the bisexual or lesbian sisters were found to have significantly more “male-typical” finger length ratios on average compared to their straight counterparts.
Meanwhile, among the male twins, the bisexual or gay brothers had more “male-typical” hands than the straight ones—contrary to what the researchers expected—althought the difference was not significant.
“Because identical twins, who share 100 percent of their genes, can differ in their sexual orientations, factors other than genetics must account for the differences,” the authors wrote in the study.
For example, different exposure or reactions to hormones in the womb, unique to each twin pair, could contribute to their differing sexual orientations.
“Research suggests that our sexuality is determined in the womb and is dependent on the amount of male hormone we are exposed to or the way our individual bodies react to that hormone, with those exposed to higher levels of testosterone being more likely to be bisexual or homosexual,” the authors wrote. “Because of the link between hormone levels and difference in finger lengths, looking at someone’s hands could provide a clue to their sexuality.”
The latest study is not the first to suggest a link between finger length and sexuality. However, it is important to stress, that the evidence is currently not strong enough to predict whether someone is gay, straight or bisexual based on the ratio between their fingers.