Testosterone levels seen prior to birth in fetus’ fingers, jawline

A close look at a newborn's hand can show much testosterone the child was subjected to while in the womb, new research has found.

A child’s index finger to the ring finger ratio plays a role in the shape of a face – and it can be seen even before a boy hits puberty.

Digit ratio is non-invasive and easy to measure and has the potential to provide clues about an individual's prenatal history.

Research: The study found that if the index finger is the same size or longer than the ring finger, the child is more likely to have a narrower chin and a more feminine face

The research found that if the index finger is the same size or longer than the ring finger, the child is more likely to have a narrower chin and a more feminine face.

But if the index finger is shorter, the boy’s face will be rounder and have a more masculine look.

Researcher Sonja Windhager, an anthropologist at the University of Vienna, told LiveScience: 'The overall shape patterns associated with high and low digit ratios depicted in our sample of boys closely resemble the ones found for adult men'.

She added: 'In an ongoing study, we are now collecting data of adolescents to compare the magnitude of shape difference associated with [second finger to fourth finger ratio] before and after puberty'.

And that’s not all the fingers show.

Handyman: A study in the Asian Journal of Andrology found a correlation between finger length and the length of a man's penis

Last year, a study in the Asian Journal of Andrology found an association between finger length and the length of a man’s penis.

Men whose index fingers are shorter than their ring fingers may have longer penises, according to the study out of South Korea.

Tae Beom Kim at the urology department of Gachon University Gil Hospital in Incheon, South Korea, said: 'According to our data... the shorter index [second] finger than ring [fourth] finger you have, the longer stretched penile length you have'.

Previous studies have shown strong evidence that prenatal testosterone may determine finger development as well as penile length, a relationship that Kim and his colleagues launched the survey to focus on.

Man's men: Actors Robert De Niro and Mickey Rourke are both included among those with round, masculine faces

The study involved 144 men suffering from urological problems that did not affect the length of their penis, which was measured under anesthesia.

Thus, combined with other information, digit ratio offers the potential for clinical usefulness, wrote McQuade in an email reply to questions from Reuters.

The female index and ring fingers tend to be about the same length.

A 2010 study said that men with long index fingers have a lower risk of prostate cancer.

Researchers at Britain's Warwick University and the Institute of Cancer Researcher found that men whose index finger is more extended than their ring finger were one-third less likely to develop the disease than men with the opposite pattern of finger length.

Reference

Boys’ Testosterone Levels Before Birth Seen In ‘Manly’ Fingers, Strong Jawline

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