Study Claims A Person's Sexuality Is Linked To The Shape Of Their Hands


Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

clockOct 18 2018, 17:31 UTC


A new study claims that people's sexuality can be determined by looking at their hands. And just like fortune tellers that read palms, you should consider this study with an abundant and healthy dose of skepticism.

According to the research, published in the Archives of Sexual Behavior, women that have an index finger and ring finger of different lengths on their left hand are less likely to be straight. Previous studies have assumed that the difference in index-to-ring-finger ratio has to do with exposure to testosterone. Males generally have a longer ring finger compared to their index finger. In women, the two fingers tend to be the same length. In this study, the team wanted to avoid confounding factors so they used identical twins.


The researchers looked at 18 pairs of identical female twins and 14 pairs of identical male twins. All twins had discordant sexual orientation. For the female twins, the non-straight ones had more “masculine” left hands compared to their heterosexual counterparts. But even given this result it is extremely unlikely that you can work out someone’s sexuality based on their hand.

First of all, the number of participants in this study is small, so it is difficult to make an assumption about the general population. Finger length, just like sexuality and gender, is a spectrum. The length of fingers has been linked to athletic prowess and intelligence, and the desired “traits” are often attributed to the masculine configuration of finger length.

Second, it is important to know that the connection between finger length and testosterone is far from confirmed. This idea, known as the Manning hypothesis, is widespread in biological and biobehavioral studies, but it is yet to be verified clinically. A paper from six years ago failed to confirm the hypothesis.

Third, sexuality cannot have a single cause. And it is definitely not all due to testosterone. Sexuality is likely defined by many factors. Some genetic, some epigenetic, and some environmental, like the order of birth.


Human sexuality is complex and somewhat fluid, and linking it to a single agent like testosterone is limiting our understanding of it. On top of that, approaching such a problem by expecting gay and bisexual men to have more feminine finger lengths simply plays into old stereotypes that we should have moved beyond in 2018.

“For 14 male pairs, non-straight twins had, contrary to our prediction, more masculinized finger length ratios than straight co-twins, but this difference was not significant,” the authors wrote.

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