For centuries, palm readers have promised paying customers that the secrets of the future are written in the lines of their hands.
Although there are no real love lines waiting to be read, some scientists believe that our hands can really tell us a lot about ourselves.
More specifically, scientists have studied the so-called 2D:4D ratio, which represents the relationship between the index finger and the ring finger.
This ratio has been linked to everything from athletic performance and obesity to aggression and even psychopathic tendencies.
But not every scientist is convinced of this. So read on to find out what your hands could reveal about you.
Some scientists argue that the ratio between your index and ring fingers, or the 2D:4D ratio, can reveal a lot about yourself
The difference between your fingers may seem pretty arbitrary, but scientists believe it may be a clue to how you developed in the womb.
Dr. Ben Serpell, a sports scientist from the University of New England, told Web that the 2D:4D ratio is linked to your mother's hormone levels.
Dr. Serpell explained: “The 2D:4D ratio is thought to be established as early as the end of the first trimester in the womb and is influenced by prenatal testosterone exposure.”
“Given that testosterone is an androgenic hormone, meaning it results in characteristics that many would consider more 'masculine,' women typically have a higher 2D:4D ratio than men.”
He also suggests that prenatal testosterone is associated with testosterone sensitivity later in life.
Because the ratio is related to the male sex hormone, researchers often focus on traits thought to be related to testosterone sensitivity.
A longer ring finger than index finger
If your ring finger is significantly longer than your index finger, it means you have a low 2D:4D ratio.
It's worth noting that men almost always have a lower percentage than women because they are exposed to more testosterone before birth.
But if you're a man or woman with an exceptionally low 2D:4D ratio, then there might be cause for celebration.
In his research, Dr. Serpell a low ratio as a potential sign of success among Ruby players, surgeons and political journalists.
The reason for this was that responsiveness to testosterone is related to the ability to absorb and process information.
He says: “We argue that 2D:4D may predict the ability to maintain focus. “By continuing to focus on a task, we argue that those with low 2D:4D will be successful at that task.”
Rugby players like England's Tom Curry may be known for having huge hands, but the ratio of their fingers could be just as important. Studies suggest there is a link between a longer ring finger and success in rugby, as testosterone sensitivity is linked to increased concentration and attention
Other studies have also found a connection between a low 2D:4D ratio and physical fitness parameters in young professional footballers.
In 2021, an international team of researchers published an article in BMC Sports Science, Medicine, and Rehabilitation that examined 24 players under the age of 17 to measure their fitness and finger length.
They found that the larger the ring finger was in relation to the index finger, the better the athletes performed in terms of strength and fitness.
But it's not all good news, as a low ratio is also associated with several “negative” traits.
A 2005 study of 298 students at the University of Alberta found that lower 2D:4D ratios were associated with higher levels of aggression in men.
The researchers even found that men with lower rates received more penalties over the course of a hockey season.
Researchers found that students with lower 2D:4D ratios were more aggressive and received more punishments for their behavior over the course of a hockey season. Perhaps the behavior of Nicolas Roy (right) of the Vegas Golden Knights, seen here being called for a penalty against Ryan Graves of the Pittsburgh Penguins (left), can be explained by his finger ratio
Perhaps most shockingly, a lower ratio has also been linked to opioid abuse disorder, antisocial personality disorder, and even psychopathic tendencies.
The researchers say their findings suggest psychopathy may have “biological roots.”
Dr. Seyed Sepehr Hashemian, a psychoanalyst who worked on the work, told Web: “We were surprised to observe such a linear relationship between higher symptoms of psychopathology and lower 2D:4D ratios.”
“The more an adult participant exhibited signs of psychopathology, the more it appeared that that adult was exposed to higher concentrations of testosterone and lower concentrations of estrogen during the prenatal period of life.”
However, he also points out that while testosterone might predispose someone to a certain behavior, it is not their “unchangeable destiny.”
He adds: “While some characteristics associated with a lower 2D:4D ratio may be viewed negatively in certain contexts, they may also be beneficial in others, such as in competitive or challenging situations.”
From The Joker to Patrick Bateman (played by Christian Bale, pictured), psychopaths have appeared in many famous blockbuster hits over the years, but some scientists say you could tell if you have psychopathic tendencies by the length of your fingers has
A longer index finger than ring finger
On the other hand, your index finger may be longer than your ring finger.
If this is the case, you have a high 2D:4D ratio.
Aside from being associated with the opposite of all low ratio traits, some studies have looked specifically at this trait.
A higher 2D:4D ratio is believed to be a sign of lower testosterone levels and higher estrogen exposure in the womb.
Studies suggest that high levels are associated with greater pain in various situations.
In a 2017 study, researchers at the Medical University of Lodz found that out of 100 men and women who underwent reconstructive nose surgery, a higher proportion in women were associated with greater postoperative pain.
On the bright side, a 2015 study from the International Headache Center in Beijing found that women with a higher 2D:4D ratio were less prone to migraine headaches.
If your hands look like this, some scientists believe you may have a lower pain threshold and be at higher risk of developing obesity
A 2022 study, also from the University of Lodz, pointed out the role of estrogen and testosterone in shaping gender-specific fat accumulation.
Women, according to a group of researchers, tend to store more fat in their arms, legs and thighs than men.
Based on this assumption, researchers then examined the finger ratios of 125 adults to see if there was a connection to weight gain.
They found that a higher proportion was associated with the development of obesity in both sexes.
Does that really work?
This list of characteristics related to finger size only scratches the surface of the thousands of studies that have been published on the topic.
The 2D:4D ratio has also been linked to sexual orientation, parental poverty, right-handedness, period pain, grip strength, jump height and the chance of becoming a firefighter.
But if you feel like the 2D:4D ratio is associated with almost every feature possible, you're not the only one, and not everyone thinks that's a good thing.
The fundamental problem is this, explained Dr. Gareth Richards, a psychologist at Newcastle University, said this is all based on the assumption that finger length is a good indication of prenatal hormones.
Dr. Richards told Web: “The evidence that this is actually the case is far from convincing.”
Scientists worry that measuring your fingers, as this chart suggests, gives no real indication of the hormones you were exposed to in the womb. Since this theory was first proposed, there has been little convincing evidence that this is the case
Measurements of babies' hands and their mothers' hormones have not provided good evidence that the 2D:4D ratio is a good indication of whether someone has been exposed to higher testosterone levels
But if there is no good evidence that the 2D:4D ratio actually measures what it claims, then why are there so many studies claiming to have found connections between finger length and various characteristics?
Professor James Smoliga, a physiologist from Tufts University, told Web that this was due to the so-called 'file drawer effect'.
He says: “What happens is that people make tons of different measurements and for most of them there is no biological cause-and-effect relationship.”
“But through sheer bad luck you’re going to end up with something that’s statistically significant.”
“The reason it's the file drawer effect is that if you find something statistically significant, you publish it, and if not, you put it back in the file drawer.”
To prove his point, Professor Smoliga devised an experiment deliberately aimed at finding a false connection.
He used X-rays to measure the finger bones of over 180 subjects and recorded both their body fat percentage and their luck at various completely random games.
He found that the 2D:4D ratio had a statistical relationship with body fat composition.
But it had an even stronger correlation with how lucky someone was when drawing random poker hands from a deck.
Apparently Professor Smoliga didn't want to prove that finger ratios bring luck, but rather that you can associate the 2D:4D ratio with anything if you try hard enough.
Although the statistical association is about as strong as anything related to the 2D:4D ratio, it was so small that it is more likely to be a coincidence than a real effect.
HOW CAN YOU MEASURE YOUR 2D:4D RATIO?
To measure your finger, stretch it straight and look at your palm.
Wrinkles may form at the base of your index and ring fingers. Your index finger probably has a crease, your ring finger is a crease.
Select the crease closest to the palm and select a point on the crease in the middle of the base of the finger.
Mark it with a pen. Measure it from the mark to the tip of your finger.
To measure your finger, stretch it straight and look at your palm. Wrinkles may form at the base of your index and ring fingers. Your index finger probably has a crease, your ring finger is a crease