For quite a few years researchers have assumed that finger length development and the 2D:4D digit ratio is directed by sex hormones. Nevertheless, until now direct experimental evidence was lacking. However, researchers from Florida have reported an important discovery. They discovered via a study of the limb buds in mice – which are known for having a digit length ratio similar to humans – that human fingers are likely to have likewise sex hormone receptors as seen in the paws of mice.

 A few comments made by researchers Martin Cohn (one of the researchers from Florida) and ‘finger professor’ John Manning:

“The discovery that growth of the developing digits is controlled directly by androgen and estrogen receptor activity confirms that finger proportions are a lifelong signature of our early hormonal milieu,” Cohn said.
“I’ve been struggling to understand this trait since 1998,”said John T. Manning, Ph.D., a professor at Swansea University in the United Kingdom, who was not involved in the current research.“”When I read this study, I thought, thank goodness, we’ve attracted the attention of a developmental biologist with all the sophisticated techniques of molecular genetics and biology.” “When Zheng and Cohn blocked testosterone receptors, they got a female digit ratio,” Manning said. “I find this completely convincing and very useful,” Manning said.“We can now be more focused in our examination of the links between digit ratio and sex-dependent behaviors, diseases of the immune system, cardiovascular disorders and a number of cancers.” “He suggested that the 2D:4D ratio would be an interesting question, and I have to admit to being skeptical,” Cohn said. “When he came back with the initial results, I was blown away. We looked at each others hands, then got busy planning the next experiment.”

The new discovery provides a genetic explanation for a raft of studies that link finger proportions with traits ranging from sperm counts, aggression, musical ability, sexual orientation and sports prowess, to health problems such as autism, depression, heart attack and breast cancer.

The report about the new study appears in this week’s Proceedings of the National Academy of Sciences.


An overview of some key-reports about finger ratios:

http://www.handresearch.com/news/digit-ratio-finger-length.htm

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Basketball on a finger.

Basketball on a finger.

Basketball fingers,
enemas & fat
:

You may have thought it was simply a matter of being able to grip and control the ball better, but according to researchers at the University of Alberta and the University of California-Riverside, individuals with longer fingers are more inclined to voluntarily participate in intense physical exertion.

The good news:

This means that if you absolutely detest exercising, it may not be due to laziness or lack of willpower; it might be that you’re just… short-handed.

The bad news:

Although the researchers [R.H. Yan, et al.] believe their findings are applicable to humans, the study actually involved 1,000 white mice. And you probably weren’t even aware that mice had fingers.

READ FURTHER ABOUT FINGER LENGTH & ATHLETIC ABILITY:
A secret your finger length reveals
Busted by digit ratio and bikini
Athletic ability revealed by your finger length
Finger length related to autism
The finger news