The length of the ring finger may indicate a propensity to drink alcohol

Researchers have found that the relative length of the ring finger (fourth finger) to the index finger (second finger) may indicate the level of alcohol consumption.

There is a belief that alcohol consumption may be due to sex steroids affecting the body before birth. Researchers decided to study this link using a sample of 258 students, including 169 women. They found that people with a longer ring finger relative to the index finger (i.e. a low 2D:4D ratio) tended to drink more alcohol.

Professor John Manning from the A-STEM (Applied Sport Technology, Exercise and Medicine) team at Swansea University said:

Alcohol consumption is a major social and economic problem. It is therefore important to understand why there are significant differences in alcohol consumption between individuals.

Research has shown that men tend to consume more alcohol and have higher rates of alcohol-related mortality than women. This may be related to sex hormones such as testosterone and estrogen.

The finger length ratio (2D:4D) is thought to be an indicator of testosterone (long ring finger) and estrogen (long index finger) levels in the period before birth," explains Professor Manning. - Alcohol-dependent patients are known to have a significantly longer ring finger than the index finger, indicating a high exposure to testosterone relative to estrogen before birth. As expected, these links were stronger in men than in women.

The researchers hope their findings will help to better understand the factors underlying different patterns of alcohol consumption, from abstinence to casual drinking to harmful dependence.

The work is the latest in Professor Manning's series of studies on finger length ratios. He has previously investigated how this metric can provide important information about the effects of COVID-19 infection, as well as oxygen consumption in footballers.

More information: Barbara Ślawski et al, Is Alcohol Consumption Pattern Dependent on Prenatal Sex-Steroids? A Digit Ratio (2D:4D) Study Among University Students, American Journal of Human Biology (2024). DOI: 10.1002/ajhb.24187