By comparing your index and ring fingers, a neuroscientist can tell if you are likely to be anxious, or a good athlete. Can tell a woman is slutty too

[Franjipani]

Your fingers show your athletic potential and anxiety​

Date:October 12, 2016
Source:The Norwegian University of Science and Technology
(NTNU)

Summary:By comparing your index and ring fingers, a neuroscientist can tell if you are likely to be anxious, or if you are likely to be a good athlete.

www.sciencedaily.com
It is well-known that adults whose index finger is shorter than their ring finger were exposed to greater amounts of testosterone when they were in the womb.

Both women and men with this characteristic are -- on average -- better equipped to solve mentally demanding 3D rotation tasks as adults. As a group, they also have better physical and athletic abilities, but are more prone to having ADHD and Tourette's syndrome.

Why on earth is this the case? Both boys and girls are exposed to testosterone in the womb. Everyone has different levels of male and female sex hormones. Some men have a lot of testosterone, some have less, and the same applies to women. Women who have received a lot of prenatal testosterone don't need much testosterone as adults.

The level of testosterone in utero affects one's finger length as an adult.

24 women and a drop of testosterone

"The relationship between the index finger and ring finger in particular indicates how much testosterone you have been exposed to in utero," says Carl Pintzka, a medical doctor and researcher at the National Competence Service for Functional MRI.

In his doctoral dissertation at NTNU, Pintzka investigated how the brain functions differently in women and men. As part of this study, he tested an established theory about the significance of finger length and how the brain works.

He measured the finger length of 42 women and gave half of them a drop of testosterone. The other half were given a placebo. Afterwards, the women had to solve various mental tasks.

Short index finger, more testosterone

"We could then look at how testosterone levels affect different abilities in healthy women both in the womb and in adulthood," says Pintzka.

An index finger that is relatively short compared to the ring finger indicates that one has been exposed to a lot of testosterone in utero, whereas a relatively long index finger suggests a lower exposure to testosterone in the womb.

"One mechanism behind this relationship is the difference in the receptor density for oestrogen and testosterone in the various fingers in utero. This relationship has also been shown to remain relatively stable after birth, which implies that it's strictly the fetal hormone balance that determines this ratio," says Pintzka.

More testosterone, better sense of place

The relationship between the index finger and ring finger in humans is associated with a variety of abilities in adulthood.

"The greatest effect has been found for various physical and athletic measures, where high levels of prenatal testosterone are consistently linked with better capabilities," Pintzka says. "Beyond this we find a number of uncertain results, but a general feature is that high levels of testosterone generally correlate with superior abilities on tasks that men usually perform better, such as various spatial tasks like directional sense," he adds.

Conversely, low levels of testosterone are associated with better abilities in verbal memory tasks, such as remembering lists of words. Fetal hormonal balance also likely affects the risk of developing various brain-related diseases.

… but also more ADHD and autism

Pintzka says studies show that high levels of testosterone in utero correlate with an increased risk of developing diseases that are more common in men, such as ADHD, Tourette's and autism. Low levels of testosterone are associated with an increased risk of developing diseases that are more common in women, like anxiety and depression.

His study primarily involved researching how testosterone affects different spatial abilities in women. The women were asked to navigate a virtual maze, and to mentally rotate different three-dimensional objects.

More study needed According to Pintzka, the study results indicate a trend towards a positive effect of high testosterone levels on spatial abilities in utero. He believes that a larger study would be able to show a significant correlation. Furthermore, the results suggest that these hormone levels are important both in utero and in adulthood.

In other words, no definite conclusions can be drawn quite yet. Pintzka found no prenatal hormonal effects on study participants' ability to navigate a virtual maze.

"The women who scored best on the mental rotation tasks had high levels of testosterone both prenatally and in their adult lives, while those who scored worst had low levels in both," says Pintzka.

 

[Franjipani]

The future is in your hands
nypost.com

Your destiny just might be in your digits.

Measure your fingers from the crease they make with the palm to the top of the digits — if the index finger is shorter than the ring finger, you might just have a higher chance of becoming an alcoholic.

German researchers recently studied 131 patients detoxing from alcohol addiction and compared their hands to those of 185 “healthy volunteers.” The ratio between the length of the index and ring fingers “was lower in the [alcohol addicted] patients,” according to Johannes Kornhuber, director of the psychiatry clinic at the University of Erlangen-Nurmberg.

“We found both a lower digit ratio in alcohol-dependent women compared to healthy women, and a lower digit ratio in alcohol-dependent men compared to healthy men.”

Simply by studying someone’s hand, Kornhuber says, science can identify people who are at risk, or could benefit from preventative measures: “It’s astonishing.”

Kornhuber’s addiction study is just the latest research in the growing study of finger length and “digit ratio” — the depth of difference in length between a subject’s index and ring fingers. For about 10 years, biologists, psychologists and economists have linked digit ratio to promiscuous sexual proclivities, heart disease, ADHD, eating disorders, sports ability, musical genius, autism, sexual orientation, fertility, penile length — even the success of high-frequence financial traders.

Finger lengths are fixed at birth and are determined by the amount of prenatal testosterone a fetus receives in the womb. Exposure to higher levels of testosterone in utero — the hormone surges between the ninth and the 18th week of gestation in the womb — result in stubbier index fingers that are shorter than ring fingers.

Men tend to have ring fingers that are longer than their index fingers, while women generally have index and ring fingers of the same length. The differences in digit ratios between races, however, is large. Caucasians, for example, generally have a higher ratio between their index and ring fingers — i.e., a bigger difference in length — and blacks and Asians have a lower ratio. It’s unclear why.

But because brain development is affected by the same prenatal exposure to sex hormones that determine finger length, scientists are parsing the hand to try and explain more opaque developments in the brain.

And researchers at the University of Texas Health Science Center at San Antonio, have manipulated the pre-natal testosterone levels in baboons to learn more about how these steroids affect neurology.

Anthropologists have been aware of “fingerology,” or the study of finger lengths, for over a hundred years. It has long been accepted science that the disparity in length between fingers is accentuated in the right hand versus the left.

But it wasn’t until the late 1990s that biologists started employing the second-to-fourth finger ratio — referred to as the 2D:4D ratio — as a way to predict a person’s future behavior and health.

The field has exploded over the past few years, with researchers across the globe trying to add to the growing list of behaviors correlated with finger length.

If their findings are true, a visit to the physician or the shrink might be as simple as faxing over a Xerox of your palm.

Women with high digit ratios — index and ring fingers that are the same length — are said to be more fertile and carry a higher risk of breast cancer, according to numerous studies.

Studies even suggest a correlation between prenatal hormones and future food hang-ups. Anorexic and bulimic women have significantly lower digit ratios — much shorter index than ring fingers — than their healthier counterparts.

Researchers at Berkeley have found lower digit ratios among homosexual women, positing that these women were exposed to higher levels of testosterone in the womb.

For men, differences in digit ratios between gay and straight men were strongest among whites, according to an experiment commissioned by the BBC.

In men, however, a ring finger that towers over the index is considered a sign of high fertility, according to the studies.

Among men who suffered heart attacks in their 30s and 40s, a larger number were shown to have high digit ratios.

More masculine digit ratios, i.e., a shorter index finger in both men and women, have been correlated with Attention Deficit Hyperactive Disorder, or ADHD.

The masculine digit ratio has also been correlated with people who are more aggressive, have higher musical aptitude and are better at sports — in particular, football.

In recent years, even economists have even entered the field.

“A low digit ratio makes you more likely to take calculated risks,” says Aldo Rustichini, an economist at the University of Minnesota, who used digit ratio to accurately predict how long traders would survive in the business.

Traders with a lower digit ratio made, on average, six times more in profits than their colleagues who were doing the same job and analyzing the same data.

“This is a very simple measure of your personality,” Rustichini says. “It’s revealing.”

Korean scientists, publishing their findings in the Asian Journal of Andrology, have even found digit ratio to be a predictor of adult penile length.

The researchers studied 144 Korean men, ages 20 and up. One researcher measured the lengths of their fingers, while another researcher measured their flaccid and “stretched” penile lengths while the test group were under anesthesia.

The findings, published last month, concluded there was a strong correlation and that “digit ratio can predict adult penile size and that the effects of prenatal testosterone may, in part, explain the differences in adult penile length.”

But boiling down a person’s behavior and physiognomy to the length of his index finger, not surprisingly, has attracted its share of skeptics.

“It’s possible that androgens [i.e., testosterone] affect digit length,” NYU biologist Claude Desplan says. “But, for sure, our brain is much more than just how much androgens we got during gestation.”

Other critics said studying fingers for clues about personality is nothing but a gimmick.

“In my mind, digit length would neither be the most direct nor accurate way to figure out something about a person,” said Clifford Tabin, chairman of the genetics department at Harvard Medical School. “While we can speculate about what [this] means for behavioral imprinting, there’s no hard evidence of it having a definable effect.”

For now, digit ratio has remained a sideshow to Ivy League researchers, with the bulk of studies taking place abroad. It’s been ignored by prominent science journals such as Nature and the Journal of the American Medical Association (JAMA).

But the growing body of research has many contemplating the implications of wearing your medical history and personality on your hand.

Would you list your digit ratio on a resume, or an online dating site? Would it be unethical for potential employers to take a long, hard look at your hand when greeting you for a job interview?

“It’s like not trying to measure IQ,” says Rustichini, who conducted the study on traders. “If we think we are interested in putting the right people in the right job, it’s a bad idea not to look at this information.”

But Tabin says that “there’s a difference between finding something statistically significant, and looking at a particular person and predicting something based on finger length. In terms of saying, ‘look at these fingers, [this guy] is going to have a heart attack,’ you don’t know the entire genetic background . . . I find the work to be in the marginally significant, over-interpreted category. Others may feel differently.”

Nora Charles, a post-doc fellow in the psychiatry department at the University of Texas Health Science Center, who has studied digit ratio and its association with women’s interest in uncommitted “riskier” sexual relationships, defends the study.

“It’s a newer tool that’s on the market and there’s a lot of debate in the field,” says Charles. “A lot of scientists think it’s useful and some are still skeptical, but that’s just the nature of science.”

 

[Franjipani]

So if a woman has a longer ring finger than index finger, chances are she's promiscuous.

 

[JurongEast]

So if a woman has a longer ring finger than index finger, chances are she's promiscuous.

Can a promiscuous woman be a virgin at the same time

 

[steffychun]

@Balls2U like?