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2nd digit to 4th digit ratio? - Printable Version

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2nd digit to 4th digit ratio? - jamixoxo - 03-03-2015

Interesting... length of index finger divided by length of ring finger as an indicator of androgen exposure in vitro.
http://en.m.wikipedia.org/wiki/Digit_ratio

As near as I can tell, mine is exactly 1.00, not sure how I feel about that, but I like anything that shifts the paradigm a little!

Measure from the palm side, bottom crease of fingers at palm to tip. Both hands. Divide index finger length by ring finger length. Lower ratio suggests higher androgen exposure in vitro, evidenced by more enhanced masculine traits, amongst some issues. Higher ratio suggests lower exposure, evidenced by muted masculine traits.
No correlation on fetal estrogen levels.
That's my abstract anyway...
[attachment=9019]

-j

RE: 2nd digit to 4th digit ratio? - flamesabers - 04-03-2015

My index finger on both hands are slightly longer than my ring fingers.

I have heard of this before and I'm not sure what to make of it. It strikes me as an oversimplification of scientific facts at best, at worse it's misleading. According to the wikipedia article you cited, a high digit ratio suggests traits such as a reduced risk of video game addiction and a greater possibility of having superstitious beliefs. Also, the article suggests a high digit ratio correlates with males preferring butch females or other men for sexual partners. Lastly, what is 'masculinity of handwriting?'

Ultimately I would be more interested in the science of how androgen exposure influences the development of our fingers than anything else.

RE: 2nd digit to 4th digit ratio? - jamixoxo - 05-03-2015

All good observations Flame... And I agree; grains of salt required Wink

It all started with news surfing and I ran across this:
http://blog.aarp.org/2015/02/27/why-women-should-check-a-mans-finger-size/?intcmp=AE-BL-IL-BLOG

Which led me to this abstract:
http://www.sciencedirect.com/science/article/pii/S0191886914006400

And this one (which suggests there is likely an answer to your question):
http://www.earlyhumandevelopment.com/article/S0378-3782%2804%2900012-X/abstract

After that, I poked around a few other places, and it appears the correlation regarding hormone exposure in vitro is well documented... Some of the other attempts to extrapolate social habits, sexual orientation, gender identity, etc likely show so much scatter that truly valid correlation is unlikely.

I decided to post the Wikipedia entry because it provided a broad overview (at the expense of accuracy)... And it comes with a handy chart Rolleyes

I agree, before I buy this one fully I want to see some real data... Population, sample sizes, scatter, etc.

-j



RE: 2nd digit to 4th digit ratio? - sfem - 05-03-2015

For your reading pleasure:
http://www.tgforum.com/wordpress/index.php/transgender-science-recap/


RE: 2nd digit to 4th digit ratio? - jamixoxo - 06-03-2015

(05-03-2015, 10:20 PM)sfem Wrote:  For your reading pleasure:
http://www.tgforum.com/wordpress/index.php/transgender-science-recap/

Thanks sfem!

I think this sums it up fairly well:
"In addition to DNA markers there are body markers that indicate DNA involvement. Both MTF and FTM transsexuals are less right handed than controls and have low 2D:4D finger length ratios. (Contrary to some, finger length ratios are determined by DNA, not prenatal testosterone.) FTM have body markers in the teeth and hips."

Although the correlation cited appears to be opposite shown in the graph and the literary abstracts (I just wonder if she transposed it).

Pretty good article, just wish she'd included some citations. Gonna see what I can turn up.


-j

RE: 2nd digit to 4th digit ratio? - sfem - 06-03-2015

More info:

http://www.sciencedirect.com/science/article/pii/S0301051105000542 this one says they really don't know, and it might all be hogwash
http://www.sciencedirect.com/science/article/pii/S0018506X08001529 this one tries to take aim at GID and possible correlation with finger ratios
http://www.epjournal.net/blog/2012/04/the-2d4d-ratio-a-new-paper-points-the-finger/ this one discusses why quite a few researchers have flawed results, they started from a flawed point (or two)

A lot of the time, studies and research only seek to build on existing studies or research. Far too few do independent confirmation or original work.


RE: 2nd digit to 4th digit ratio? - EvaMarie - 06-03-2015

Mine are in the feminine range but my middle fingers are a bit longerTongue

Seriously though it was kinda cool the last time I saw my Mom and our hands are an EXACT matchSmile

I also have a female carry ratio...

http://en.wikipedia.org/wiki/Elbow

That explains why I never could throw a baseball very well and why I always had trouble doing certain weight lifting exercises...

RE: 2nd digit to 4th digit ratio? - Candace - 07-03-2015

Mine is 1.11, which is so extreme that I've found only one chart that goes out that far.