Does your finger point to PCOS?

by Amy Medling, founder of PCOS Diva

One day while eating lunch in my high school cafeteria a friend pointed out how my ring finger was longer than my index finger. All the girls at the table started looking at their fingers and found that their index and ring fingers were about the same size, yet I was the only girl at the table with a longer ring finger. I shrugged it off and never really thought much of it until I started researching PCOS.

Finger length has been studied since 1888. Males are more likely to have longer ring fingers, and females tend to have ring and index fingers closer in length. However, it does seem that many women with PCOS also have longer ring fingers, much like men do. There have been some small studies, most recently a study of 285 women from India, that shows women with longer ring fingers have a high probability of developing PCOS in adult life.

Recently on the PCOS Diva Private Community Facebook Page, a PCOS Diva asked if other Divas had longer ring fingers than  index fingers. Out of the many women who commented on the post, about ¾ had one or both ring fingers longer than index fingers. There was so much interest in this topic, I thought I’d investigate further.

Research does seem to suggest that the finger length ratio is influenced by the balance of testosterone and estrogen in the womb during early pregnancy. Higher testosterone exposure in the womb may be linked to having a longer ring finger than the index finger, while lower testosterone exposure may be linked to having a more even ring and index finger.

Once we are born, our fingers then grow in proportion to the size they were in the womb. So, finger length potentially could be used as an indicator of environmental factors the infant was exposed to in the womb. However, prenatal hormone exposure in the womb can not be tested without risks to the fetus.

While it is interesting that so many women with PCOS have longer ring fingers, we can not use it to predict PCOS or confirm that it is caused by exposure to androgens in the womb. There was a research study done in 2012 by PCOS researchers, including Daniel Dumesic, who has been on the PCOS Diva Podcast. The study was the first to experimentally manipulate a primate to test the hypothesis that fetal testosterone exposure results in a longer ring finger to index finger in female offspring.

Researchers used monkeys to simulate high androgen environments in the womb to see if it would affect finger length. Researchers found that until advances in technology permit safe and accurate measurement of human fetal blood concentrations, or identification of a reliable postnatal biomarker of early-to-mid-gestational androgen exposure, understanding fetal testosterone contributions to finger lengths and to the origins of PCOS will remain elusive and inconclusive. Experimental possibilities in this field are highly limited for ethical reasons.

While researching for this blog post, I found some interesting and kind of crazy findings, here are a few…

You can find out if you’re predisposed to longer ring fingers on 23 and Me

A gene causing the index finger to be shorter than the ring finger is said to be dominant in men but recessive in women, with the result that more women have longer index fingers than men. 23andMe has identified genetic markers that make you more predisposed to longer ring fingers.

If you are a member of 23andMe.com you’ll find on your dashboard that there is a “Health Trait” called Finger Length Ratio that will give you a percentage based upon your genetic profile whether you may be genetically predisposed to having a longer ring finger. I just looked at my dashboard and I’m 63% likely to have a longer ring finger.

Women with longer ring fingers tend to more assertive and competitive

Nine hundred and eighty-five women provided self-reports on the length of their fingers and their degree of assertiveness, without knowledge of the hypothesized link. Women whose index was shorter than their ring finger were more likely to describe themselves as “assertive and competitive” than women whose index finder was longer than their ring finger. This finding could reflect the simultaneous effect of prenatal sex hormones on body and brain. Another study showed that women with a longer ring finger than the index finger are bold, innovative, and risk takers.

Women who have an index finger shorter than their ring finger may be stronger

A longer ring finger in women as compared to index finger was shown to be linked to higher grip strength in adulthood. Researchers measured the digit ratios and handgrip strength of 125 healthy women between 19 and 31 years of age from a remote region in Austria.

Handgrip strength was measured using a dynamometer – a device with a handle that’s often used for routine medical screening of patients’ grip strength.

The researchers found a longer ring than index finger was positively associated with handgrip strength and therefore muscular fitness. The researchers controlled potential confounding factors, such as age, environment, ethnicity and exercise, that could have influenced the association.

Children born mothers with above-average income had longer
ring fingers than index fingers

In 2021 researchers from Swansea University in the UK surveyed 250,000 people across 200 countries and were asked to measure their index and ring fingers, along with indicating their parent’s income level.

The researchers found that children born to a mother with an above-average income had ring fingers that were longer than index fingers.

Hungry people with longer ring fingers make “more masculine food choices”

When people were hungry, masculine digit ratios led to masculine food choices, the study found. However, this effect only works when people were hungry did not effectively predict satiated people’s food choices. When people were hungry, masculine digit ratios led to masculine food choices, the study found researchers recruited 216 Chinese people, half of whom were women and half men. When hungry people with longer ring fingers chose more masculine food vs. feminine food (see list:)

• Shrimps (f) or lobster (m)
• Fillet of fish (f) or fillet of beef (m)
• Diet Coke (f) or Coca-Cola (m)
• Caesar salad (f) or burger with fries (m)
• White wine (f) or hard liquor (m)

While finger length isn’t a diagnostic criterion of PCOS, it is sort of a fun exercise to see how many of us have a longer ring fingers and to see how having this physical trait may impact different aspects of life.

Amy Medling, the best-selling author of Healing PCOS and certified health coach, specializes in working with women with Polycystic Ovary Syndrome (PCOS), who are frustrated and have lost all hope when the only solution their doctors offer is to lose weight, take a pill, and live with their symptoms. In response, Amy founded PCOS Diva and developed a proven protocol of supplements, diet, and lifestyle programs that offer women tools to help them gain control of their PCOS and regain their fertility, femininity, health, and happiness.

 

Resources

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2. Garn SM et al. (1975). “Early prenatal attainment of adult metacarpal-phalangeal rankings and proportions.” Am J Phys Anthropol. 43(3):327-32.

3. Gillam L et al. (2008). “Human 2D (index) and 4D (ring) finger lengths and ratios: cross-sectional data on linear growth patterns, sexual dimorphism and lateral asymmetry from 4 to 60 years of age.” J Anat. 213(3):325-35.

4. Manning J et al. (2014). “Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations.” Front Endocrinol (Lausanne). 5:9.

5. Voracek M et al. (2010). “Relationships of toe-length ratios to finger-length ratios, foot preference, and wearing of toe rings.” Percept Mot Skills. 110(1):33-47.

6. Warrington NM et al. (2018). “Genome-wide association study identifies nine novel loci for 2D:4D finger ratio, a putative retrospective biomarker of testosterone exposure in utero.” Hum Mol Genet. 27(11):2025-2038.

7. Williams TJ et al. (2000). “Finger-length ratios and sexual orientation.” Nature. 404(6777):455-6.

8. Zheng Z and Cohn MJ. (2011). “Developmental basis of sexually dimorphic digit ratios.” Proc Natl Acad Sci U S A. 108(39):16289-94.

9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3425513/

10. https://doi.org/10.1016/j.jasi.2017.12.006

11. https://www.sciencedirect.com/science/article/abs/pii/0191886983900612

12. https://doi.org/10.1098/rspb.2021.2328

13. Journal of Biosocial Science, Volume 54, Issue 1, January 2022, pp. 154 – 162 DOI: https://doi.org/10.1017/S0021932021000043

14. https://www.sciencedirect.com/science/article/pii/S0950329320304377?via%3Dihub