Digit Ratio?

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Can someone please tell me more about this digit ratio phenomenon and how it is correlated with autism?

http://en.wikipedia.org/wiki/Digit_ratio
This is just one fo dozens of articles.

It ties in with the foetal-testosterone thingy.

Supposedly, people with any type of autism should have a longer ring finger than index finger on their dominant hand.

Well, it IS interesting. It says that autistic people tend to have a lower ratio, averaging .94. Another site ( http://www.autismresearchcentre.com/doc ... g_etal.pdf ) says AS ratio tends to be .935 to .945. Autistic is .945 to .955. Most sibling kids about .982 to .998, with mothers and fathers of normal kids WELL within the normal kids spans. MY span is approximately 0.938. ANOTHER site said men average .95 and women average .96!

What I would like to see would be the range of the autistics' digit ratios. Did every one of the autistics used have a digit ratio like that---or were there some autistics who had digit ratios closer to 1.00? The ratios posted were averages---so there had to be ones that were higher ratios---right? But how much higher? I would like to see the percentage breakdown at each ratio for these autistics. And how big was the testing sample?

I have also seen that Asperger's are closer to NTs on this---around 0.975 for men.

I am diagnosed with Asperger's, but I don't quite have that ratio. Mine seems to come out at like 0.9875.

Our hands can look deceiving. Upon holding my hands up in front of me from the back sides---both my ring fingers look noticeably longer than my index fingers. From the palm side holding them up, my right hand's ring finger looks barely longer than the index finger, and my left hand's looks like the index finger is longer than the ring finger. Upon measuring my left hand, I get like 1.00.

I photocopied my hands, I measured and measured and measured---and it's like you get all these different readings. But 0.9875 seems to be my right hand ratio.

I might add that I have seen other posts/threads on this digit ratio thing. There are a lot of diagnosed Asperger's people here who do not fit that ratio---men and women. So what about that? I am really interested in this.

Thank you to those of you who replied to this topic. I am also very interested in this.

How would I be able to measure my own digit ratio?

You can probably best understand it by finding a site on how to measure. But...

you take your palm side and measure from the crease where the finger attaches to the hand (you need to take the center of the crease because the index finger crease is at an angle which can vary the measurement a lot) and measure out to the tip. Then you divide the length of the index finger by the length of the ring finger. That gives you the ratio.

Oh...the ring finger probably has a couple crease lines where it attaches to the palm---you take the crease nearest the palm. A lot of the sites say to photocopy the hand and do the measuring.

I hope I explained that correctly.

0.92 for both hands (they're both the same, really, even if the lengths of each hand are different), and measured as it says in Cohen's paper (ventral side and from the creases); physically, I do show signs of excess testosterone as an adult.

Of note, they do say this is for children, rather than adults (they do measure the hands of parents and siblings, but they aren't the ones with autism).

Anybody remember 'phrenology' ?(if I spelled it right)

garyww wrote:

It's sometimes amazing to see so-called 'new' science dredged up from the remnants of quackism. I even understand that there is a strong movement back to Eugenics in some parts of the world as a cure-all for everything that ails everybody.

I have to agree, it does sound like a lot of old science dredged up. I even read on one of the digit ratio study sites that you had to be careful in measuring because it was often open to bias readings. I noticed that---depending upon how you hold your hand can alter readings. I was able to get readings on my right hand at 0.965 to 1.00 depending on how I stretched out my fingers. I would think if there was any validity to this study, they would have to take X-rays and measure the bone length. But again, as garyww pointed out---it sounds like just a bunch of old scientific things dredged up from quackism.

Even for the xrays, it is PROVEN FACT that a number of people have taken growth hormone, and grown large hands because of it. In theory, that would make testosterone have less of an effect, if any at all, and it DOES go right down to the bone. Since it can happen artificially, and has been known to happen to an extreme degree through genetic or physical abnormalities, well...

That makes sense 2ukenkerl---I never thought about the growth hormones. I've never taken any myself. As was also mentioned earlier, the studies have been done on children. I would think that as we grow into adults, our ratios could change a bit---I think.

Even though I am not sold on this digit ratio thing (I am like garyww on this), I would like to see the range of ratios obtained for the children in that study that were diagnosed with autism. Since those were averages, there had to be higher and lower ratios recorded.