You already know that every individual has a unique fingerprint, but did you know these fingertip swirls are usually asymmetrical? Most of us have more fingertip ridges on our right hands than our left.

Gay people are different. We tend to have higher left hand ridge counts. 30% of us have more fingertip ridges on our left, whereas only 14% of straight people have more on their left hands.

Fingertip swirles seem an odd thing to count, but they tell us something important. Fingertip patterns are highly inheritable, with genetics accounting for 90%–95% of the variation. Our fingerprint swirls are also fully developed by the 4th month of pregnancy, meaning this trait is not affected by other factors in birth, childhood, or later in life.

Body asymmetry is important because it correlates with the ability to perform certain cognitive tasks. Those with higher right hand counts excelled at tasks where men typically excel, and those with higher left hand counts excelled at tasks where women typically excel. Knowing the link between asymmetry and cognitive functioning we learn that fingertip swirl counts tells us there are gender or sexual-orientation related cognitive patterns based in our DNA, factors determined at the moment of conception.

Summary:

  • Gay Men: Tend towards higher fingerprint ridge counts on the left hand indicating pre-natal differentiation.
  • Lesbians: Same effect as gay men.

Source:

  • J.A.Y. Hall and D. Kimura, Dermatoglyphic asymmetry: Relation to sex, handedness and cognitive pattern, (1994) Behavioral Neuroscience, 108, 1203-1206

This article is part of a series, Written on the Body, exploring the correlations between our body structures and sexual attraction.