Talk:Digit ratio/Archive 2

How is it measured?
The article is still lacking a source on how the finger length is actually measured. The suggested method ("from the bottom crease") seems to be inaccurate and ambiguous.--93.220.14.151 (talk) 22:29, 28 January 2013 (UTC)
 * I have given a journal citation. I consider that this following paragraph from the journal could be use as a source.--Senthi (talk) 02:56, 29 January 2013 (UTC)

Digit measurements
Identical digit length measurements were taken from every photocopy, using digital callipers accurate to 0.01 mm. To eliminate bias due to inter-observer errors, all digits were measured by one observer. The lengths of 2D and 4D were measured from the midpoint of each proximal crease to the distal finger tip. These measurements were used to calculate the 2D:4D ratio (obtained by dividing 2D by 4D length) and the 2D-4D difference (obtained by subtracting 4D from 2D). Another measure, referred to as the ‘distal tip extent’ (DTE) was taken. In effect, this affords a different method of estimating the 2D-4D difference and was adapted from the ‘tip measure’ described by Manning et al. (2000). A line was drawn between the midpoints of the 2D and 4D proximal creases to account for hand shape. Two further lines were then drawn parallel to this, one at the point of the 2D distal finger tip and one at the 4D distal finger tip. The distance between the 2D and 4D distal tip lines was then measured at 90° to the lines, giving the ‘distal finger tip extent’. The purpose of using both the DTE and 2D-4D difference as outcome measures was to assess the comparative worth of alternative digit measures. source:Journal of Anatomy, Volume 211, Issue 5, pages 630–638, November 2007 http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7580.2007.00801.x/full

Simpler terms
Can somone put this stuff into simpler terms, ie., is an index finger longer than a ring finger more feminine?

Bolegash (talk) 05:27, 7 April 2012 (UTC)

Yes, basically. A longer ring finger suggests more exposure to testosterone in utero while a longer index finger suggests the opposite. The list of traits associated with each ratio is rather long and much more complex than just masculinity and femininity, though. AlexanderKaras (talk) 06:43, 11 May 2013 (UTC)

Is "retard" an encyclopaedic word?
I'm just a random, sexually insecure person who happened to have stumbled on this article. Got to the section about traits associated with 2D:4D ratio when I saw this

"Some retards suggest"

Not that I care. I'm not a retard. Just letting you know. Cheers. — Preceding unsigned comment added by 90.203.205.147 (talk) 16:00, 30 August 2013 (UTC)

The visualization is incorrect
The figure with the text "A visualization of the distributions: Men (blue), women (green), and the whole population (red)." Is wrong. The green line combining the two normal distributions is wrong; see http://en.wikipedia.org/wiki/Sum_of_normally_distributed_random_variables for how to correctly sum normal distributions. — Preceding unsigned comment added by 84.23.128.94 (talk) 19:50, 4 February 2015 (UTC)

Ambiguous wording in Intro
Regarding the second paragraph of the intro:

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 in females.[citation needed]

Though I'm fairly certain I understand which digit they mean by second, it could still be read ambiguously: is it meant as the second of all five fingers (the index finger) or the second of the two being mentioned (the ring finger)? Perhaps this would be best remedied by replacing the word "second" with the accurate finger's name. 50.144.0.139 (talk) 21:17, 3 April 2015 (UTC)Tom in South Florida

About "High digit ratio linked to Asperger's syndrome"
(I placed this comment by mistake also in Wikipedia talk:WikiProject Anatomy). In the paragraph "Correlation between digit ratio and traits", I think there is an error in interpretation of a scientific source. Or at least, confusion can be caused. In the table, there is an item "Increased rate of Autism Spectrum Disorders (when comparing digit ratio to general population)[52]" in the column "low digit ratio" (which is completely correct, no problem here), and an item "Increased rate of Asperger syndrome (when comparing digit ratio to person's father)[52]" in the column "high digit ratio" (which is somewhat problematic).

The reason the second item is problematic is the following. The whole table is about traits, compared to general population. The item about Asperger's however, in the right column, refers to the expected digit ratio compared to the father's digit ratio (which is of little interest in a table about traits, and confusing as it might lead people to believe that Aspergers have a high digit ratio, while in reality they have a low digit ratio).

The confusion is even enlarged by the fact that nowhere in the table is mentioned that, compared to general population, Aspergers have lower digit ratio. The source [52], which is this article: "The 2nd to 4th digit ratio and autism, is very clear on this point: "Children with AS (...) had higher 2D:4D ratios than children with autism but lower ratios than population normative values."

I changed the article "Digit ratio" as follows:
 * in the column "low digit ratio" I added "and Asperger's syndrome" to the item "Increased rate of Autism spectrum disorder (when comparing digit ratio to general population)[52]"
 * in the column "high digit ratio" I removed the item about Asperger's digit ratio compared to the expected ratio according to the father's. (Maybe it can be put elsewhere in the article). It is not exactly wrong, but confusing (see above), and out of place in the table about traits (it's more about the hereditary question than about general traits).

(I am new to editing/talking on Wikipedia, so I apologize for any errors, mistakes or bad practices.) --Bartvanaudenhove (talk) 17:11, 17 May 2015 (UTC)

Penile length
The sources quoted for the item "penile length" (supposedly inversely correlated with digit ratio) all point to the same single study, which seems to be very questionable, especially the maths behind the so-called correlation. See article Male Genital Length Study Falls Short and, cited by that article, also Friday Weird Science: Will this spoil the surprise?. I would propose to remove the item about penile length? --Bartvanaudenhove (talk) 17:11, 17 May 2015 (UTC) Update: as argumented in above paragraph and since on-one objected in about a month, I removed the item about "penile length". --Bartvanaudenhove (talk) 17:23, 11 June 2015 (UTC)

Need for help
Hello can anybody introduce me a comprehensive source of information about digit ratio? I need information about latest approaches to biotechnological and biomedical aspect related to digit ratio specially D2:D4 ratio. Thank you — Preceding unsigned comment added by My info account (talk • contribs) 16:02, 11 June 2015 (UTC)
 * this article has a link to "500 studies" .... All the best: Rich Farmbrough, 17:14, 1 August 2015 (UTC).

Two questions

 * 1) The article mentions specific finger length ratios, but it's not clear from the article where the baseline for measuring the length of a finger actually is, whether the measurement should include the knuckle or not.
 * 2) The article mentions studies of digit ratios (2nd-to-4th) specifically in the hind limbs of mice, pheasants, and apes, but nothing about toe length ratios in humans.  Are certain hormones expected to influence toe length the same way they influence finger length in humans?  Why or why not?

-- 75.164.215.67 (talk) 20:21, 26 December 2015 (UTC)

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Left vs right digit ratio
This study compared a number of factors including salivary testosterone and digit ratio between "gifted" and normal children. They found that the digit ratio between the groups was only prominent with respect to the digit ratio of the left hand. Perhaps this should be mentioned or more research to this effect should be sought? http://ac.els-cdn.com/S0160289614001524/1-s2.0-S0160289614001524-main.pdf?_tid=d6946408-1175-11e6-b951-00000aab0f6b&acdnat=1462311029_67576cb847c5d6baf5d5b4c7cf10bcd6 — Preceding unsigned comment added by 208.90.213.186 (talk) 21:45, 3 May 2016 (UTC)

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Unclear second paragraph in introduction?
The second paragraph reads, "The 2D:4D digit ratio is sexually dimorphic: although 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 in females." Wouldn't this mean that males have extremely low and extremely high digit ratios, whereas these ratios are average in females? In addition, the abstract of the source cited at the end of the paragraph says about digit ratios, "Men on average have fourth digits longer than their second digits, while women typically have the opposite." which is not what the paragraph in this wiki suggests (unless I misunderstood it). — Preceding unsigned comment added by 2001:14BB:140:6F1A:85BB:65AF:6A19:FB29 (talk) 16:37, 11 March 2017 (UTC)

Contradictory information in table
in the table for low ratio for cognition there are these contradictory points:
 * Mathematical ability
 * Decreased mathematical ability

The other is this point under low ratio:
 * Right hand low digit ratio predicts academic performance

And for high ratio:
 * Higher exam scores among male students

So how does that work? People with high ratio get higher exam scores, but at the same time low digit ratio somehow get better grades than high ratio?

Can someone clarify? Otherwise it might make sense to remove it as they seem to cancel each other out and as it stands is just confusing. — Preceding unsigned comment added by 207.6.36.128 (talk) 03:12, 3 May 2017 (UTC)

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Reduced performance in sports
This is only for males, right? I checked https://doi.org/10.1016/S1090-5138(00)00063-5 and https://www.ncbi.nlm.nih.gov/pubmed/11182575 — Preceding unsigned comment added by 134.76.62.2 (talk) 17:35, 7 October 2017 (UTC) and it was only about males. So it should be "Reduced performance in sports in males" (sorry if I made a mistake, I am german) — Preceding unsigned comment added by 134.76.62.2 (talk) 17:30, 7 October 2017 (UTC) ===

Agreed (Pseudoscience)
It is particularly questionable whether this ratio is related to in-utero testosterone exposure. In fact, two studies in mice contradicted each other. The journal Hormones and Behavior won't accept papers that assume this ratio is related to in-utero testosterone. The ratio difference is most likely related to larger hand size in men compared to women. Please see the studies referenced in the following article: https://www.sciencemag.org/news/2019/06/talk-hand-scientists-try-debunk-idea-finger-length-can-reveal-personality-and-health — Preceding unsigned comment added by 2600:8806:A100:73:DD59:CECA:AE1A:880F (talk) 04:23, 15 October 2020 (UTC)

Heritability of Digit Ratio

 * https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5566275
 * https://pubmed.ncbi.nlm.nih.gov/16611491/
 * https://onlinelibrary.wiley.com/doi/abs/10.1002/ajhb.23212
 * https://www.nature.com/articles/s41598-021-92358-x
 * https://journals.sagepub.com/doi/10.2466/pr0.100.1.115-126
 * https://www.sciencedirect.com/science/article/pii/S0378378217302517
 * https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0060419 183.179.53.41 (talk) 05:20, 9 August 2022 (UTC)

Pseudoscience
This is nothing but pseudoscience. It should be deleted from Wikipedia. There is no evidence finger length has anything to do with sexual orientation. The vast majority of women are straight including those with longer ring fingers than index fingers. The subject is just crap.


 * I believe this topic is notable enough to not warrant deletion, however compared to how this page treated Digit Ratios as a scientific topic a year ago, it is now much better at highlighting pseudoscience taking place (removal of low quality content, a criticism section, and criticism of the science throughout the article). Unfortunately there are no high quality sources outright declaring it pseudoscience (despite many sources eviscerating the topic, and/or comparing to pseudoscience), making it difficult to treat it as such with high modality. It's unfortunate that this page took so long to treat it as bad science. Burger Double (talk) 02:11, 23 October 2022 (UTC)


 * Both articles claiming that this subject is pseudoscience admit there is scientific evidence that digit ratios are real. In one, it says, "Although the finger ratio is usually smaller in men, the gap between the sexes is small. In the BBC internet study, average right-hand values for men and women were 0.984 and 0.994, respectively." In the other article, it says, "Berkeley researchers based their conclusions on the hands of 720 volunteers they recruited at street fairs in San Francisco." Both articles admit there is evidence for digit ratios that has been published. They think it has being exaggerated or misunderstood. Calling digit ratios pseudoscientific due to these articles is not warranted. 2603:7000:8800:950F:E979:8FC0:6E55:9CDD (talk) 12:56, 14 December 2022 (UTC)


 * Although the sexes statistically have different trends, as the criticism section outlines the pseudoscience taking place is when it is incredulously used as a proxy variable and/or correlated against a trait. That aspect is also the only reason this article and the research field exists. — Preceding unsigned comment added by Burger Double (talk • contribs) 01:06, 1 January 2023 (UTC)

It is not Pseudoscience
The reference sources for calling Digit ratio as a pseudo-scientific topic are not neutral and valid, we cannot call something that has thousands of articles in the scientific journals like Nature as pseudo-science.

For example, a recent study (2021) published in Nature supports the effect of prenatal hormones on the sex roles of gay men:

https://www.nature.com/articles/s41598-021-87338-0

In addition, in this Wikipedia article, the statistically significant effects of Digit ratio on autism or facial masculinity are confirmed, but at the beginning of the article and it contradicts the rest of the article.

It is strongly recommended to revise the beginning of the article. 5.113.221.65 (talk) 17:46, 27 January 2023 (UTC)
 * The study wasn't published in Nature. Brunton (talk) 00:14, 28 January 2023 (UTC)


 * The study has been published in Scientific Reports and reposted in Nature for researchers to read and if you don't know Scientific Reports has a 2-year impact factor: 4.996 (2021), and is the 5th most-cited journal in the world, with more than 696,000 citations in 2021
 * The question I ask again is why While the subject has many researches in scientific journals claimed as pseudoscience??

5.113.221.65 (talk) 08:04, 29 January 2023 (UTC)
 * It is not neutral and valid to treat Digit Ratios as a legitimate topic, consdiering every time the research approaches the mainstream it is trashed upon, look at John T Manning's attempt to get a headline with his covid-19 papers and their replies.
 * Yes this subject has a large volume of research, however you're assuming that this is indicitive of quality rather than this being a very easy topic to P-Hack (as Smoliga's paper very thouroughly demonstrates).
 * Reposting in nature doesn't make this any more legitimate, Nature has published/reposted pseudoscience before (https://www.nature.com/articles/s41598-017-09970-z https://www.nature.com/articles/s41598-022-24727-z).
 * If we are also considering the treatment of this topic by journals, then we should also consider that Kim Wallen after becoming editor of Hormones and Behaviors (a journal one would assume has more focus on this topic), decided to stop accepting papers on the topic https://www.science.org/content/article/talk-hand-scientists-try-debunk-idea-finger-length-can-reveal-personality-and-health . I also did a bit more digging and found out that this didn't come from speculation, but instead reflects his findings that: "Berenbaum and colleagues’ landmark study makes untenable a notion that variation in digit ratios solely reflects variation in prenatal androgens." https://academic.oup.com/endo/article/150/11/4819/2455391
 * On that note, the wikipedia article should be updated to reflect that paper. Burger Double (talk) 00:48, 7 February 2023 (UTC)