Glancing at a man’s ring finger, you can usually figure out whether they are married or single. Interestingly enough, the very same finger on their left hand might help determine how their body will react to a COVID-19 infection—and even whether they live or die. According to a new study published in the journal Early Human Development, men who have longer ring fingers have a reduced chance of death from a coronavirus infection, and are more likely to face mild symptoms.
While it has already been established that gender is a risk factor when it comes to the highly infectious and contagious virus, with men more likely to get seriously ill than women, this study delves deeper into what makes one man more prone to getting severely sick, while others may show no symptoms.
Researchers analyzed data from 103,482 men and 83,366 women in 41 countries, measuring ring fingers in relation to index fingers. They found that a smaller “digit ratio,” meaning the ring finger is longer than the index—translated to a lower fatality rate. While they did also look at the lengths of women’s fingers, they found no correlation.
Testosterone Plays a Role
Researchers believe this has to do with why some men have longer ring fingers than others. According to science, it all has to do with how much testosterone men are exposed to in utero—the greater the hormones, the longer the ring finger. Testosterone is also thought to increase the concentration of angiotensin-converting enzyme 2 (ACE2) in the body, which helps fight against severe coronavirus-related illnesses.
“The theory is that someone with high prenatal testosterone—and a long ring finger—has greater levels of ACE2,” explained one of the study’s authors, John Manning of Swansea University, to The Sun. “These concentrations are large enough to oppose the virus.”
A Potential Worldwide Biomarker
Interestingly, researchers found this trait in countries such as Malaysia, Russia and Mexico, where the coronavirus fatality rate was lower. Men proved to have a higher digit ratio in the United Kingdom, Spain and Bulgaria—countries with a higher fatality rate. Men in countries with longer ring fingers have an average death rate of 2.7 per 100,000, while in countries where finger length is shorter, the average is significantly higher, at 4.9 per 100,000.
Researchers hope their findings “may provide a biomarker for male COVID-19 susceptibility,” helping “identify those for whom it would be advisable to exercise social distancing.”
As for you: To get through this pandemic at your healthiest, don’t miss these Things You Should Never Do During the Coronavirus Pandemic.