A new study has suggested that finger length could provide clues to a person’s sexuality.
Researchers at Essex University looked at sets of identical twins where one of each set was straight and found that on average the homosexual twin had a greater difference between the length of their index and ring finger.
Previous research indicated that exposure to the male hormone testosterone in the womb could be linked to differences in finger length.
Women’s index and ring fingers are typically of similar length while in men there is a greater difference.
Both men and women are exposed to the “male” hormone testosterone in the womb.
The study observed that in 18 sets of female twins, the lesbian twin had more “male-typical” hands than her straight sister.
In 14 sets of male twins the gay twin had slightly more “male-typical” hands than their straight brother but the difference between the two was not viewed as significant.
Dr Tuesday Watts, from the department of psychology, said because identical twins share 100 per cent of their gene, but can differ in sexual orientation, factors “other than genetics” must account for the differences.
“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,” Dr Watts said.
“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 findings are published in the journal Archives of Sexual Behaviour.