A team of researchers from Swansea University (UK) has announced that our affinity for beer begins even before we are born.
Ordering another pint at the bar often feels like a spontaneous decision. However, a remarkable new study has revealed that our inclination towards alcohol consumption is shaped long before birth.
How Was the Study Conducted?
Led by Professor of Evolutionary Biology John Manning, the team measured the lengths of the ring and index fingers of 258 adult students—89 men and 169 women. They also inquired about the participants’ drinking habits, recording the results in grams of alcohol consumed over a week.
The researchers based their findings on the premise that all individuals are influenced by testosterone in the womb, and that everyone has varying levels of male and female sex hormones.
According to the study’s results, the more testosterone (the male sex hormone) we are exposed to in the womb, the more alcohol we tend to consume in adulthood. Meanwhile, finger length serves as an indicator of how much testosterone affected us before birth, and thus, how “masculine” we are.
A Few Words About Professor Manning’s Theory
In academic circles, Professor John Manning is well-known for his work on the 2D:4D ratio—the lengths of the second (index) and fourth (ring) fingers. He posits that if the ring finger is longer than the index finger, it indicates that the individual was exposed to higher levels of testosterone in the womb. Conversely, if the index finger is longer, it suggests a greater influence of estrogen (the female sex hormone).
The 2D:4D ratio serves as a biomarker for the balance between testosterone and estrogen in the fetus. By dividing the length of the index finger by the length of the ring finger, one can derive a measure of the testosterone exposure in the womb. A lower ratio indicates more masculine traits, while a higher ratio suggests greater femininity, as reported by the Daily Mail.
What Did the Researchers Report?
The team found that the link between alcohol consumption and a low finger ratio was most pronounced in men with long ring fingers on their right hand.
However, the exact reason for this connection remains unclear. Professor Manning suggests that elevated testosterone levels in the body may increase alcohol tolerance because it is absorbed into the bloodstream to a lesser extent.
“Enzymes in men’s stomachs can reduce alcohol absorption into the bloodstream by 30 percent, while in women, it is absorbed in greater quantities,” noted the lead researcher.
The team acknowledged that the study only included students, which may represent a rather specific sample regarding drinking habits.
The findings were published in the American Journal of Human Biology.
What Else Do Scientists Know About This Strange Correlation?
Previously, researchers at Swansea University found that children born to high-income mothers tend to have longer ring fingers.
“High-income mothers may experience elevated testosterone levels (compared to estrogen) in early pregnancy, leading to the masculinization of their children, regardless of gender. Conversely, women with low incomes may have lower testosterone levels, resulting in the feminization of their children of both sexes,” Professor Manning stated at the time.
A 2021 study from the University of Vienna showed that women whose ring fingers are longer than their index fingers (indicating significant prenatal testosterone exposure) have stronger hands.
Additionally, Scandinavian researchers discovered that hungry individuals with longer ring fingers than index fingers are more likely to order typical “masculine” foods, preferring steak over salad.