Talk:Digit ratio/Archive 1

Archived talk page content

2006 update needed
We are halfway through 2006, and several new articles have come out on "digit ratio." These are easily found on Google Scholar and should be incorporated. -- W. L. (Bill) Overal, 05 June 2006.

Merge proposal
This really ought to be merged with 2d:4d (which is a better article), but I think the main article ought to be called Digit Ratio. They both need work. I'll see if I can find some time over the next couple of days. Pete.Hurd 14:18, 15 September 2005 (UTC)


 * I completely concur on merging. The main article should be Digit ratio, and 2d:4d should redirect to it. Lulu of the Lotus-Eaters 06:06, 19 September 2005 (UTC)


 * I did some work on Digit ratio, and I think it contains all of 2d:4d that was worth merging here. I don't know how much of the rest of 2d:4d is worth moving to Biology and sexual orientation or prenatal hormones and sexual orientation but as far as I'm concerned 2d:4d can be depreciated in favor of Digit ratio (which still needs some work). Pete.Hurd 06:19, 19 September 2005 (UTC)

Being bold on merge
Below is the text of 2d:4d that I just redirected here. I think Pete.Hurd has done a good job in transferring any important parts, but the below contains the prior page in case anyone wants to work in additional material. Lulu of the Lotus-Eaters 06:37, 19 September 2005 (UTC)

Prior text
2D:4D is a sexually dimorphic trait of 2nd and 4th (digit) finger ratio to propose that prenatal androgen level influences sexual orientation in both sexes.(2D:4D, male <female, that related to individual's prenatal exposure to testosterone (PET))

This would means that male's 4th digit would normally be longer than their 2nd digit. In comparison, female's 2nd and 4th digit length are normally similar.

The importance of 2D:4d are still under research. Due to its nature as a sexually dimorphic trait (different between male and female) many researcher speculate that it correlates with genderization of brain functions such as sexual orientation, spatial orientation, verbal ability, mathematical ability, aggression level, even sexual performance ability.

—I don't know if this is true, but i have measure my digit ratio and i have 0,90 (and i measure it in both hands)... And i am not autist, that's for sure. What this means? I am a big guy, and well, intelligent, maybe it has some connection to this?

2D:4D and sexual orientation
The origin of homosexuality may involve psychological or biogenic factors. However, attempts to test psychological models have led to negative findings (Rahman and Wilson, 2003). In contrast, there is accumulating support for genetic and neurohormonal influences on homosexuality (Lippa, 2003).

Although the suspicion of androgen hormones (DHEA, DHEA-S, testosterone, and androstenedione) causing female rodent (mouse) homosexuality is not a new one (Meyer- Bahlburg, 1984). The original research inject androgen hormones into female rodent's womb, which leads the female fetus grow up to be "lesbian". The "lesbian" female would try to mate with other female when fully grown. Also its brain functional pattern are closer to male than female.

It was Bogaert and Hershberger (1999) who linked such relationship to male homosexuality. This link was investigated in the recent past. In year 2000, an article in Nature from Berkley stirred up researchers’ interest on such link. (Williams, Pepitone, Christensen, Cooke, Huberman, Breedlove, Breedlove, Jordan, & Breedlove, 2000).

Williams et al. (2000) used the sexually dimorphic trait of 2nd and 4th (digit) finger ratio (2D:4D, male <female, that related to individual’s prenatal exposure to testosterone (PET)) to propose that prenatal androgen level influences sexual orientation in both sexes. They found homosexual males and females have significantly lower 2D:4D ratios than heterosexuals. It implied that both homosexual males and females have higher PET. This finding was later supported by various researchers (Csathó, Osváth,, Bicsák, Karádi, Manning, and Kállai, 2003; Brown, Finn, Cooke, and Breedlove, 2002; Lalumiere, Blanchard, and Zucker, 2000; Lippa, 2003; Rahman and Wilson, 2003; Robinson and Manning, 2000).

"Europe vs. North American straight man effect" I don't know what this is and I can't find anything on the 'net. Would you please give an explanation? A link or citation would be nice too.Stassa 18:28, 3 September 2006 (UTC)

2D:4D difference in populations
According to Manning’s (Manning, Barley, Walton, Lewis-Jones, Trivers, Singh, Thornhill, Rohde, Bereczkei, Henzi, Soler, and Szwed, 2000) the mean 2D:4D is different between populations. International research had been conducted in Poland, Spain, England, Hungary, Germany, South Africa, Jamaica, and Finland (Manning et al., 2000).

Merge from Peter L. Hurd
Please see the recent AFD, Articles for deletion/Pete Hurd, for arguments. Mine is that every one of the sources cited at Peter L. Hurd is about a study conducted by Prof. Hurd, not about Prof. Hurd. The study merits at least a sentence or two in this article. There is no sign of multiple non-trivial independent sources that are actually about Prof. Hurd, which is what we'd need to write an encyclopedia article at Peter L. Hurd.That should be reason enough to merge. However, in cases of living persons, Biographies of living persons is an extra prod for us not to keep a stand-alone article at Peter L. Hurd. Pan Dan 12:30, 20 June 2007 (UTC)
 * User:Pete.Hurd expressed a desire not to have biographical details about him at Digit ratio. I just want to emphasize that I am not suggesting doing that. I am suggesting merging into Digit ratio a sentence or two about the study, nothing about Prof. Hurd except his name as the author of the study (with his graduate student assistant). Pan Dan 12:35, 20 June 2007 (UTC)
 * Nonsense. The page on him was kept at AfD just this week, and shouldn't be reversed here. The arguments at the AfD were keep, and PH was in the end willing. He is one of the people interested in this subject, but not the only one. The above arguments were rejected, and Pan Dan is engaged in the well-known procedure of first stripping content and then trying to merge, after which people often try to remove the paragraph. I have of course restored the content. DGG 15:08, 21 June 2007 (UTC)
 * Nothing is being "reversed." A merge is a form of keep.My "stripping" of the article removed resume-type content. Please actually address the issues I raised in my edit summaries if you think the "stripping" was not warranted. Pan Dan 15:32, 21 June 2007 (UTC)

People were discussing Keep, Merge, or Delete on the AfD, so that consensus emerged for Keep not Merge suggests that Keeping and not merging is the community's will at present. FWIW, in case it affects how people view my comments, my opinion was merge, but now I will go with the community's consensus. -- Myke Cuthbert (talk) 21:30, 21 June 2007 (UTC)
 * Ummm, if you are looking for something to do, the Biography article I think is most merited relating to this topic is one for Prof. John T. Manning. That ought also to generate some needed history for this article. Pete.Hurd 22:30, 21 June 2007 (UTC)

moved here from DGG talk page
Hello DGG, User:Pan_Dan made a series of edits to Peter L. Hurd on 20 June 2007 in an attempt to force a merger of articles with the page on Digit Ratio. I think this has something to do with the article being keeped at AfD, whilst user:Pan_Dan opposed the article. The edits have been reverted by an administrator, user:Trialsanderrors once already but he has just reverted the page back again. I considered this to be vandalism and editing in bad faith as it goes against community concensus, so I reverted the edit back. Once again it has been reverted back by user:Pan_Dan. Normally I would have contacted user:Trialsanderrors in regard to this, but he is on a wikibreak. I am not experienced enough to handle this situation and would like you to take action to preserve the inclusion of this academic. Thanks R:128.40.76.3 15:01, 21 June 2007 (UTC)
 * I've restored the page. I suggest you comment also at the merge discussion on the talk page for digit ratio. DGG 15:12, 21 June 2007 (UTC)
 * DGG, I don't appreciate your reversion. I explained my edits and referenced the relevant Wikipedia policies in my edit summaries.You did not explain your reversion except to say the removal of content was "undiscussed." This is contrary to WP:BOLD; good-faith edits rooted in policy don't have to be "discussed." Pan Dan 15:17, 21 June 2007 (UTC)
 * You know, you are wrong, go back at see what it says at BOLD," But anything you end up doing that turns out badly can be reverted, often quite painlessly. Don't be insulted if that does happen". Discuss he removal of the material on the Peter L. Hurd page. Don't edit war. The best course would be to wait a month or two, and then renominate for AfD. DGG 15:21, 21 June 2007 (UTC)
 * The point is that my edits were explained and rooted in policy, and your reversion was totally unexplained except for a misguided admonishment about the need to "discuss."On your other point, I have no intention of going back to AfD. You will recall that my recommendation in the AFD was to merge, not delete. Merges don't require AFD's. Pan Dan 15:24, 21 June 2007 (UTC)
 * That may have been your recommendation, but the decision was simply keep. I've added a comment to the merge discussion at finger ratio, and, if you like, will explain further there, and of course you can discuss it as you like.One editor cannot force a merge If after adequate discussion you want to proceed via that route, the dispute resolution process should be followed. But removing content first and then proposing a merge of what remains will not necessarily suggest good faith to an uninvolved party. DGG 15:32, 21 June 2007 (UTC)
 * Your last sentence is really silly. If I thought the content at (the long version of) Peter L. Hurd was A-OK, then of course a merge would be a bad idea. The reason I think a merge is needed is that when content offending WP:NOT, WP:NPOV, and WP:OR is removed from the article, all that's left is content on the digit ratio study. My removal of the content, and the explanations in my edit summaries, demonstrate, using Wikipedia policy, why I believe a merge is necessary. (For the record, I proposed the merge before, not after (as you suggest), I removed the offending content--not that that matters.) Pan Dan 15:39, 21 June 2007 (UTC)

I will move this thread to the merge discussion at Digital Ratio. DGG 17:06, 21 June 2007 (UTC)
 * Thanks, I agree that's appropriate. Pan Dan 17:21, 21 June 2007 (UTC)

[Moved here from my talk page:] I see you reverted the attempted removal of material from the page earlier today. I've found it necessary to do it again already. If it happens another time, perhaps you could revert and protect the page. DGG 15:24, 21 June 2007 (UTC)
 * I only check WP every couple of days currently, but if you need my input let me know. It seems we have a rough consensus that the long version is policy-compliant. I don't see any interpretative claims that are not backed by multiple outside sources, and we routinely use CV's for declarative claims unless we have reason to distrust their veracity. Fwiw, I don't see any evidence of vandalism on Pan Dan's part. This seems a normal content dispute where s/he holds a minority opinion. The merge proposal is nonsense btw. If an academic is deemed notable it means s/he has reached a level of exposure that warrants a biographical article. ~ trialsanderrors 18:50, 21 June 2007 (UTC)
 * You mean a biographical article where the biographical details are sourced to the subject's website? Any CV is a self-released promotional autobiography--nothing to write a neutral, reliably verifiable, Wikipedia article with. And no, there was no consensus at the AFD that the long version is policy-compliant. There was a majority who declared Prof. Hurd "notable," but failed to explain how a policy-compliant encyclopedia article could actually be written on Prof. Hurd in the absence of multiple non-trivial third party sources about him. (BTW thanks for exonerating me of vandalism.) Pan Dan 19:38, 21 June 2007 (UTC)
 * I'm not involved with the Peter L. Hurd page but since I stopped by here, I note with interest trialsanderrors' comment that 'we routinely use CVs for declarative claims unless we have some reason to distrust their veracity.' This would indeed make life simpler for editors of biographies. Just lately the COI noticeboard is discussing Joseph Hilbe, an article where some of the details are unsourced, but they don't seem terribly important to have 'proof' of. E.g. he worked as a personal assistant to Rudolf Carnap (unsourced). So I await with interest the outcome of this idea. EdJohnston 20:58, 21 June 2007 (UTC)
 * Academic CV's are, unless they contain interpretative claims, not "promotional". They tend to make declarative claims (claims of fact) of the "X is Associate Professor at Y" and "X published a paper in Z" variety. Interpretative claims (claims of opinion) are claims such as "X is the foremost researcher in the field of W". If we want to write a neutral biography there is no reason to remove declarative claims sourced from a CV by reputable researcher or the department website. There is generally no dispute about the neutrality of a claim that X is an associate professor at a reputable university, so we don't need to reflect varying viewpoints. Interpretative claims on the other hand tend to be disputed, so we resort to outside sources to give a panoramic view of the claim. "Professor X considers himself the foremost researcher on W (source: W's CV), a claim that is disputed by Professor Q (source: ABC)." ~ trialsanderrors 22:16, 21 June 2007 (UTC)
 * I think it's just 2 steps more complicated. We are first of all talking about CVs at official university sites. People usually don't dare lie on those. (There have been cases of academics with false credentials--they usually make the Chronicle of Higher Education. That kind of investigation is usually beyond what we'd do.) But in addition CVs are acceptable as evidence for purely routine facts,such as what year a degree was awarded, etc.; they are also presumptive evidence for a degree being awarded, etc., unless disputed. I've seen them disputed, and there was recently an article at AfD with a claim to a PhD that could not be verified & the article was deleted (actually, many other facets of the bio could also not be verified, & it was just a personal web page.)   In the example mentioned, that someone worked as a personal assistant to a famous person, it would not be unreasonable to ask for additional evidence if notability depended on it. In the article that started this discussion, there was no reason to question--it was basically obstructive. DGG 22:32, 21 June 2007 (UTC)
 * T&E's distinction between declarative and interpretative claims is well taken. But neutrality doesn't just mean that we should fairly represent all points of view on interpretive claims. Neutrality also means that we should include (a fair representative sample of) all declarative claims made by third party sources. For example, "X received a Ph.D. from the University of Knowitall" is a simple declarative statement that might be found on an academic's website. "X has struggled with alcoholism" and "X was found by a University Committee to have committed plagiarism and was forced to transfer to another university" are simple declarative statements that would never appear on the same academic's website. Now, if all three statements on X above are verifiable in third-party sources, then maybe we could use those items to build a neutral article on X, including both positive and negative content. Or, if X is squeaky clean and is the subject of non-trivial third-party sources which have found nothing negative on X, then the Wikipedia article will of course reflect that. But in the absence of non-trivial third-party sources on X, a neutral article is impossible: even given verifiable declarative statements about X on X's university website, neutrality requires including information from third-party sources that have investigated X more thoroughly than the author of that university website. Pan Dan 09:16, 22 June 2007 (UTC)

--end moved here from DGG talk page--
 * there are all those national news source discussions of his work as 3rd party sources.
 * I agree that if there is negative information about his work it would be appropriate to include it somewhere, but you have never proposed any, let alone cited any. You imply the subject is not squeeky-clean without providing evidence, and I think that this is altogether out of line.DGG 03:18, 23 June 2007 (UTC)
 * That indeed would be out of line, if I had implied that. In fact I implied nothing of the sort. Please try better to understand what I was saying. I was not suggesting that Prof. Hurd isn't (or is) squeaky-clean (I have no idea). I was saying that in the absence of any third-party coverage about a subject (whether the subject is Prof. Hurd or somebody/something else), there is nothing to write a neutral Wikipedia article with. Ergo, in the case of Prof. Hurd, where no non-trivial third-party coverage is evident, it is impossible to write a sourced, neutral article.On your first point, the "national news source discussions" you mention are about Prof. Hurd's study and would not support building on article at Peter L. Hurd; in fact they support expanding Digit ratio, hence my merge proposal. It's no surprise that Peter L. Hurd is almost entirely sourced to his university webpage, because the independent sources are not about him. Pan Dan 12:43, 23 June 2007 (UTC)
 * Out of curiosity, how many of the last 20 cases on the Academics and educators deletion sorting list that were closed as keep per WP:PROF had sources that qualify as reliable under this criterion? If, as Pan Dan suggests, we delete all biographical data sourced only by official university web pages, then is there anything left but a substub for the typical WP:PROF keep?  I see Pan Dan has deleted degrees from biographical pages such as this due to lack of sources.  What proportion of biographies on WP that list academic degrees would have these degrees deleted under such a policy? Pete.Hurd 01:13, 24 June 2007 (UTC)
 * If a sub-stub remains after removing all non-indepedently-sourced content from a page whose subject has been deemed to pass WP:PROF, and no other sources are available for expansion, then either (1) WP:PROF is too broad, (2) we should accept a permanent sub-stub, or (3) we should hope that sources will eventually emerge on the subject even if none is available now. A university webpage is the perfect thing to list under External links, but filling a Wikipedia article with content from that webpage seems to me to be neither policy-compliant nor useful to the reader.(I'm not sure what relevance Justin MacKinnon has to this discussion; it was a political campaign promotion from . If I hadn't stubbed it, the next newpage patroller would've probably speedied it as spam. It certainly fit wp:csd.) Pan Dan 17:57, 24 June 2007 (UTC)
 * Official web pages are sources for routine biographical data, and if anyone wants to change that, the Village Pump is always available. Specific items of data can of course always be challenged, and if there is any reason that can be given why an entire web page is in error, that can be challenged too. As mentioned above, I did challenge it once, and the article was deleted.  The inclusion of such data has been upheld everywhere its been discussed, and it would be impossible to write most contemporary bios otherwise in all fields. The principle that such sources are accepted runs throughout WP, not just scientists.   The criteria in WP:PROF have been upheld consistently at AfD, at the rate of about 3 or 4 per week, showing they have widespread community support.  It's not DG or PH alone, but everyone who has commented.
 * My interest in this is to keep from using absurd criteria at AfD, not any particular page. Enough. WP:POINT.    DGG 04:21, 25 June 2007 (UTC)
 * Once again I'm having trouble getting my argument across to you, DGG. It's probably my fault for not being clear. So to try to clarify: I am not necessarily claiming in this discussion that no biographical data should be sourced to a non-independent webpage. I am claiming that when that webpage is the only source on a subject, then filling a Wikipedia page with information from that webpage is neither policy-compliant nor useful to the reader (I snuck the "useful" part in on my last comment; my main concern is the policy). Nor am I arguing that WP:PROF should be modified; that was just one of 3 options I laid out in my previous comment.Finally, DGG, I find it odd that you've charged me with disrupting Wikipedia to prove a point, given that this discussion is not disruptive and is the very discussion that you demanded when you reverted my edits.. Pan Dan 12:56, 25 June 2007 (UTC)
 * Hi, without getting into the whole discussion, I wanted to comment on one of Pan Dan's points: I agree completely (and think there is broad community consensus) that we shouldn't be creating pages based only on non-independent sources. I think, as you say, there is also consensus that given a notable subject with some RS, we can fill out details from non-independent sources if they are unlikely to be falsified or challenged.  Where there is some disagreement is whether a non-independent source can aid in establishing notability--I think that it can, but I know that not everyone is on that side.  -- Myke Cuthbert (talk) 17:32, 25 June 2007 (UTC)

Europe vs. North American straight man effect or why the correlation section needs a rewrite.
What a completely useless list. Are these traits positively or negatively correlated with the ratio? Strongly? weakly?

Can somebody please explain some of the items in this list - what they mean. For instance, Masculinity of Handwriting[36] -- how is this quantified? how is it judged? When it says personality what does it mean? Do guys with low digit ratio have no personality or are aspects of personality altered in some way? I can't tell. Explanations needed desperately:
 * Bem sex role score in women;[44] erotic role preference in men.[45]
 * Lesbians vs. straight women;[44][46][47][48][49][50][51][52][53][54] butch vs. femme lesbians.[55]

tried googling the following, only copies of this page came up...
 * Gay vs straight men and the very odd Europe vs. North American straight man effect.[48]

good examples:
 * Exam scores: a higher ratio is correlated with higher exam scores among male students[15][42]


 * A recent study in Germany has found a correlation between digit ratio and male to female transsexualism. Male to female transsexuals (Transwomen) were found to have a higher digit ratio than control males, but one that was comparable to control females.[56]

62.31.149.187 (talk) 22:22, 15 November 2009 (UTC)

Need help sorting out references
I've sorted through most of the old reference list, fixing errors in titles and other publication info, adding URLs, PMIDs and DOIs, reformatting with citation templates and reorganizing to use footnotes. There are a few items from the old list of references that I need some help with, though.
 * Two different possibilities for "Fink et al. 2004":
 * Three different possibilities for "Geschwind and Galaburda, 1985":
 * Unused?:
 * Can't find anywhere except in a publication list on the author's website:
 * Nelson, E.C. and Shultz, S. 2007. Using the length of the 2nd to 4th digit ratio (2D:4D) to investigate the influence of prenatal sex hormones on non-human primate mating systems and human social evolution [Abstract]. American Journal of Physical Anthropology, 132:177.
 * Cited in the text, but not listed in the references and I can't find a suitable publication online:
 * Ronalds et al. 2002
 * John Manning and Marc Breedlove (no year given)
 * Can't find anywhere except in a publication list on the author's website:
 * Nelson, E.C. and Shultz, S. 2007. Using the length of the 2nd to 4th digit ratio (2D:4D) to investigate the influence of prenatal sex hormones on non-human primate mating systems and human social evolution [Abstract]. American Journal of Physical Anthropology, 132:177.
 * Cited in the text, but not listed in the references and I can't find a suitable publication online:
 * Ronalds et al. 2002
 * John Manning and Marc Breedlove (no year given)
 * John Manning and Marc Breedlove (no year given)


 * For that Nelson article: Nelson, E. & Shultz, S. (in press). Finger length ratios (2D:4D) in anthropoids implicate reduced prenatal androgens in social bonding. American Journal of Physical Anthropology?--152.23.125.152 (talk) 00:37, 14 December 2009 (UTC)

Criticism
This newly added section sounds a bit paranoid, as though finding a sex difference or an orientation difference is used to oppress others. It offers no citations to people who have supposedly said these things, which weakens the impact. Rather than let this unreferenced point of view stand alone, it needs some balance. The cited reference talks specifically about the fallacy that digit ratios can be used to detect lesbians, and specifically describes such ideas as "misguided", so that verb should stand when citing that article. —Preceding unsigned comment added by 35.10.159.70 (talk) 21:17, 30 July 2010 (UTC)

Clarifying correlations
It would be nice if someone could go through the list of correlations and specify in each case whether the correlation is positive or negative (i.e. whether the trait in question tends to go with high (feminine) or with low (masculine) 2D:4D ratio. AxelBoldt (talk) 11:38, 4 November 2010 (UTC)

Means and standard deviations?
It would be nice to have a reference for the mean 2D:4D (and standard deviation) for males and for females, just to get a feeling for the size of the effect. AxelBoldt (talk) 11:41, 4 November 2010 (UTC)
 * An article with the pretence of presenting a 'correlation' between biological features should PRESENT this mathematical correlation, otherwise, this article is just a pile of tepid manure, getting colder. I'd even go so far as to suggest that if there is no clear statistical evidence provided by any of the articles cited, then this article should be deleted and forgotten as an urban legend, because as it stands, that's all it is.--Tallard (talk) 10:09, 5 March 2011 (UTC)

Correlation between right and left 2D:4D
It may be worth mentioning the variability between the right and left hand 2D:4D. Gallup, A.C., White, D.D., & Gallup Jr, G.G. 2007. Handgrip strength predicts sexual behavior, body morphology, and aggression in male college students. Evolution and Human Behavior, 28, 423-429 found r=.686 (females), .577 (males). I only mention it because that low of a correlation is odd. Any insights on whether this is typical for features that may be asymmetrical?--152.19.193.236 (talk) 18:26, 30 August 2009 (UTC)
 * Indeed, this article as it stands is completely useless. It uses the word correlation, but present no such correlation, the left/right hand issue is a very relevant point.--Tallard (talk) 10:13, 5 March 2011 (UTC)

Lead image is misleading
The lead image misinforms readers as to how to asses digit ratio. An open hand is completely irrelevant as the digit length must be compared from the base of the digit. Anyone can do this test right now quickly: my index finger appears longer with outstretched hand but is shorter when the hand is bent and the base of all fingers line up.--Tallard (talk) 10:17, 5 March 2011 (UTC)
 * The image seems fine to me and the article explains how the measurements are to be made. An image of an open hand with annotation showing the points of mesurement would probably be ideal Thincat (talk) 12:07, 5 March 2011 (UTC)
 * Well, thank you, 198.54.202.114. I didn't expect anyone to actually do this but I am very glad you did! Thincat (talk) 17:33, 7 March 2011 (UTC)

fascinating
I wonder if there is an evolutionary and functional reason for this? Perhaps having a shorter index finger allows you to grip things better and throw things that may be needed for fighting and hunting while the longer index finger allows you a more delicate touch, picking up smaller objects like seeds. In the wrestling world, one of the strongest grips is when your thumb rests between the other hand's middle and index finger, almost as if the index finger did not exist at all. —Preceding unsigned comment added by Mrwikipeditor (talk • contribs) 23:58, 22 January 2008 (UTC)


 * Since the dimorphism appears to be functionally neutral, it's very probable that it just happened randomly (and the pheasant study suggests at a very remote stage of evolution, before the ancestral lines of birds and mammals diverged), and it has been conserved merely because there's no particular evolutionary pressure against it. --7Kim (talk) 23:20, 23 October 2008 (UTC)

Without disrupting wikipedia to the extent that there is a place here called fascinating, I have tremendous anecdotal evidence on this. I have used to use this predominantly correct information to invoke social, coffee table discussions in the late 1990's. It seemed very accurate then among mixed populations of sexual preference and levels of aggressiveness for people born prior to 1980's. As a substitute teacher in the years 2010-2011, I was shocked to find that among high school students this did not persist. Rather most students, regardless of gender, tended toward the "masculine" profile in their finger length. My estimation, while dubious, is that the females tended toward normal female behavior, bit perhaps more aggressive sexual innuendo teasing than I had seen in high school (born 1976). Obviously, I did not continue my research after it happened twice in a population of total~ 50 students. I have continued my observations as a tennis coach at a geographically like but distinct high school (~8 miles away) while judging grips. It is concurrent. Without further information these observations are in The Midwest United States, I am guessing on the amount of relevant info used versus the potential harm, conservatively, for the location description. If someone has relevant data under these conditions I invite this as an independent affirmation. 184.9.237.239 (talk) 04:07, 14 July 2011 (UTC)

Digit Ratio and Psychopathy
A Psychopath is someone who does not have a conscious. Although the reasons are most certainly multi-factored, this brain scan study suggests there is reduced activity in parts of the brain and connections to the prefrontal cortex (most associated with impulse control). This new study suggests that psychopaths have a longer index finger. On some level this makes sense, because larger doses of prenatal testosterone, according to this study is thought to enhance connections in the prefrontal cortex, so estrogen may have the opposite effect.

Here are some casual right hand pics of (allegedly) psychopaths, and I have found the study to be anecdotally true (one must look closely):

Dominique Strauss Kahn

Eric Harris. (of Columbine) Has bizarrely long index finger.

Ted Bundy. At first I thought Ted had an even ratio, but when I printed out the picture, and measured the length, the index finger was slightly longer. (one has to cock their head to the right for the best view of hand)

The abnormal estrogen exposure, may also account for the psychopaths above aveage verbal skills according to this study.. Sempre30 (talk) 23:41, 3 June 2011 (UTC)

Went ahead and placed "psychopathy" under the "psychological disorder" sub-title in the digit ratio article. I know the condition contradicts most of what we've come to learn about aggression (testosterone derived), but I think the over-all point is any excessive prenatal exposure to sex hormones can be a detriment (balance is the key). Secondly, psychopaths (and the more benign Sociopath) often use deception, verbal skills and passive aggressive tactics to victimize their subjects, instead of raw aggression. For further research, please see the Psychopathy article where I expanded the digit ratio concept under the "Screening" sub-title.Sempre30 (talk) 21:10, 12 June 2011 (UTC)

Perhaps you meant "conscience" instead of "conscious".124.171.62.156 (talk) 13:01, 3 August 2011 (UTC)

Digit ratio and handedness, autism, other immune diseases
Deleted this section because it was poorly sourced, theoretical, misleading and redundant. Instead added a Hand Skills section in the physical and competitive behavior category. Witch Hazell (talk) 14:04, 13 September 2011 (UTC)

Correlation between digit ratio and traits
As AxelBoldt has already noted above (Clarifying correlations), this section needs to be expanded with information as to what the correlations are. Awien (talk) 18:08, 7 December 2011 (UTC)

Digit Ratio and Faculty membership
That research show that the average digit ratio of hard scientists are significantly higher than that of social scientistis. http://www.ncbi.nlm.nih.gov/pubmed/17018183 — Preceding unsigned comment added by 178.59.76.32 (talk) 22:00, 13 December 2011 (UTC)

The average should be 1,0 among females, and 0,98 for males. According to this article: http://blogs.nature.com/ericwubbo/2010/12/08/fingers-of-fate

Possible error in lede
Hello, everyone.

The lede states that: "The 2D:4D digit ratio is sexually dimorphic: in males, the second digit tends to be shorter than the fourth, and in females the second digit tends to be the same length or slightly longer than the fourth." However, under "Digit Ratio Distribution" we find that:

"Males: mean 0.947, standard deviation 0.029. Females: mean 0.965, standard deviation 0.026."

This would mean that even in females the index finger is still shorter than the fourth - only the difference is smaller. Then perhaps the lede should state that:

"The 2D:4D digit ratio is sexually dimorphic: while the second digit is typically shorter in both females and males, the difference between the lengths of the two digits is greater in males than females"

Am I getting this right? 95.136.111.181 (talk) 21:05, 15 May 2012 (UTC)

Non Exhaustive List Of Possible Traits Confusing
This is interesting but also very confusing, because it lists so many examples without clarifying if these "traits" are caused by a high or low digit ratio (or, is digit ratio itself always considered "high digit ratio?). Please clarify someone. Thanks. 78.94.33.52 (talk) 18:06, 13 June 2012 (UTC)

Also isn't this List in direct conflict with the picture and information provided with the picture????? — Preceding unsigned comment added by 27.33.4.179 (talk) 04:25, 27 August 2012 (UTC)

Correlation between digit ratio and traits
The descriptive paragraph before the list of traits suggests a correlation of high digit ratio. According to the cited sources of three of the traits they are actually correlated with low digit ratio. Those traits are increased rates of ADHD, Assertiveness in females, and reduced risk of eating disorders among males and females. I suggest that either these traits be removed or the descriptive paragraph be changed to indicate a correlation of digit ratio instead of high digit ratio. Since the overwhelming majority of traits are actually correlated with high digit ratio in the lists, I am going to delete the three that are associated with lower digit ratios. If someone feels like a change in the descriptive paragraph would be the better choice, please feel welcome to undo my change, but without a descriptor of low or high ratio of the traits the informational value, in my opinion, is reduced.

Perhaps at some point in the future a comprehensive list of traits correlated with low digit ratio and a separate comprehensive list of traits correlated with high digit ratio traits can be listed. There are quite a few new interesting findings that have been determined in research lately, associated with low digit ratios. Some of them though, are controversial.Yellowboy70 (talk) 20:44, 18 November 2012 (UTC)

Note: the Leadership and innovation traits seem questionable to me as low 2d/4d digit ratio has been associated with leadership in males in various sources, but I do not have access to the cited source in the Wiki article to determine if a negative or positive correlation of high digit ratio is suggested with those two traits in that source. Aggression is indicated as correlated with low digit ratio in that associated cited source, while not indicated as a correlation in females, so there appears to be a gray area there. Masculinity of handwriting is associated with lower 2d/4d digit ratios and dominance/attractiveness perceived in males is associated with lower 2d/4d digit ratios, in those two cited sources.

Overall, this section is confusing to me the way it is worded, but I would rather not over step my bounds here in deleting traits, except for the associations that were clearly written specific to increased or decreased traits associated with low digit ratio. At this point, in my opinion, after looking at the traits in further detail, a separate list of correlations with low as opposed to high 2d/4d digit ratio correlations, clearly described as such, could provide more clarity in my opinion, but I do not want to attempt a large edit like that, without some input from other people, that have done research on this subject.Yellowboy70 (talk) 21:35, 18 November 2012 (UTC)

Considering in the cited source, in the article, that one eating disorder, Bulimia, is reported correlated at a higher risk of developing with a higher digit ratio in females, and another eating disorder, Anorexia, is reported correlated at a higher risk of developing with a lower digit ratio in females, I undid my previous edit, as it could be looked at both ways. Considering the gray area identified in that trait and in aggression per male and female differences, rather than attempting to delete described traits that are either ambiguously correlated or not directly correlated with high 2d/4d digit ratio, the only solution I can see at this point is to add in the words "or low digit ratio", where the readers will be compelled to search the cited sources if they are seeking further details and clarity, rather than taking for granted that the introductory paragraph is correct and all the traits identified are associated with high digit ratio. In my opinion, a more diffuse description of the traits, at this point in time, is a better option than potential misinformation, until more input can be provided, developing a better method for accuracy in describing the traits and the actual correlations with either high or low digit ratio.Yellowboy70 (talk) 23:54, 18 November 2012 (UTC)

As a "compelled reader", I went through all the sources and added in descriptors for low or high digit ratio, and some minor wording refinements for consistency, in each of the listed traits. Also added in the citation for Ronolds et al. (2002), in the development section.

The trait that described a "feminine" erotic sex role preference in gay men and the correlation with lower 2d/4d digit ratio in the cited source, is what the cited source reported, if anyone cares to check behind me. I misread it at first, but re-read it several times as it seemed unexpected, considering all the other findings in the article. From the way the results were worded, apparently the author of that study found it as a surprising result, as well.Yellowboy70 (talk) 04:16, 19 November 2012 (UTC)