Talk:Human sex ratio

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I have moved most of this material out of sex ratio as I have explained at talk:sex ratio, the human material there is biasing the article by making it anthropocentric, and confusing it because general principles that apply to most sexual organisms are obscured. I will therefore move some of the material in sex ratio here. This is not deleting, it merely moving it. No doubt it will cause slight worry, but please don't panic. I am not a dog (talk) 09:48, 15 April 2008 (UTC)

Gender Imbalance[edit]

This article seems to suggest that warfare always results in an excess of males, and infanticide always results in an excess of females... this may usually (perhaps overwhelmingly) be the case, but should it be generalized? (talk) 17:47, 5 January 2009 (UTC)

Um I think you have it reversed Nil Einne (talk) 19:57, 25 April 2009 (UTC)

here the discussion of sex ratio doesn;nnnnt keep much jab kisi ko chodnay ka man kar jaye —Preceding unsigned comment added by (talk) 08:17, 2 June 2009 (UTC)

Selective contraception[edit]

Am I right in thinking that it is not necessary to have sex-selective abortion and infanticide to artificially adjust the sex ratio? Is it sufficient to indulge in selective contraception where, for example, couples have children until they have the required number of sons - resulting in males become more common in the population. Gaius Cornelius (talk) 14:49, 29 October 2009 (UTC)

Yes, but that would make a very small difference. To make an analogy ... flip a coin over and over, and write down each "heads" result as a boy, and each "tails" as a girl. Each time you get 3 boys, stop and start over. Do this 100 times, and see how many girls you have ... it will be pretty darn close to the number of boys, probably within a few percent, which is barely distinguishable from chance. -- Soap Talk/Contributions 19:13, 29 October 2009 (UTC)
Actually, pure probability theory would suggest that would have no effect at all if each couple had the same probability of producing males. However, for various reasons it would appear that some couples have a greater chance of producing males. In a population where couples tended to reproduce until they had the required number of males (two, say), couples less likely to produce males would end up having more children, leading ultimately to an excess of females.Ordinary Person (talk) 13:54, 16 February 2010 (UTC)
I think Gaius is referring to the practice of allowing a second attempt at a boy when a the first child is a girl. (China) But it still results in the same balance, ie, 33% of births are 1st born boys, 33% of births are first born girls, 16.5% are second born girls, and 16.5% are second born boys. (talk) 04:23, 14 July 2010 (UTC)

No it does result in a different balance. If the first child is a boy (50+% of the time), the couple are discouraged from having a 2nd child and thus have a 0% chance of conceiving a girl. But if the first child is a girl(50-% of the time), the couple is able to have another child, thus giving them up to a 25% chance altogether of having a male child. I'm pretty sure this isn't the most mathematical way of explaining it. Either way I find that the infanticide and gender selection abortion rate estimates alone simply doesn't correlate to the high imbalance in gender ratios in this particular country with such a large population. This needs a review, it cannot simply be assumed that infanticides and selection abortions that no one know about is the only cause of the gender imbalance. — Preceding unsigned comment added by (talk) 08:07, 28 February 2014 (UTC)

Why do we have the part about "generally higher life expectancy of females", including variations by different countries under "Natural Ratio" and then we have a much bigger dramatic section on "Gender imbalance" caused by violence against women (Kristof, Nicholas and Sheryl WuDunn. Half the Sky: Turning Oppression into Opportunities for Women Worldwide. Knopf, 2009. ISBN 978-0307267146). This seems very biased to me, it's a known fact (documented in Wikipedia's own article on life expectancy in fact) that while some of the higher life expectancy of females may be simply biological a big part of it is due to preventable causes including the higher likelyhood of violent death for males globally (for example this World Health Organisation report showing more than twice as much death from Intentional Injuries for males than females The current article seems to imply that men dropping like flies for whatever reason (nobody cares anyway right) is the natural order of things.Helixdq (talk) 03:16, 2 November 2010 (UTC)


I am adding a self contradiction tag:

Under Social factors - "Sex-selective abortion and infanticide are thought to significantly skew the naturally occurring ratio in some populations, such as China, where the introduction of ultrasound scans in the late 1980s has led to a birth sex ratio of 1.19 (2005 data), according to Chinese Academy of Social Sciences."

Under Gender imbalance - "Gender imbalance is a demographic effect that may arise as a consequence of various factors ranging from war casualties to intentional gender control. Although the ratio of female newborns to male newborns around the world is always essentially 50/50 at birth, when governments and agencies count the number of males and females in the world later, there are consistently fewer females than males." 08:31, 13 February 2011 (UTC) —Preceding unsigned comment added by (talk)

I've removed the tag and reworded the sentence by just adding the word natural. Whoever wrote that must have meant to exclude the effects of sex-selective abortion. Soap 13:32, 13 February 2011 (UTC)
Actually, I think it needs more work. I've made another change, but I'm not really good with words, so feel free to change what I wrote. Soap 13:35, 13 February 2011 (UTC)

The map[edit]

Australia should be green shouldn't it? (sex ratio of '1' according to 'list of countries by sex ratio' )

There are more than one map on this page, the biggest one has blue for boy bias and pink for girls, and is very clear. However the other charts use 'Red' for boys. This Red colour looks rather pink on my cheapo monitor, and would not be for someone who is colour blind. Leaving aside that boy=blue girl=pink is a Western culture bias, all charts on the page should use the same key. I think the big chart key, (boy=blue, girl=pink) is clearer. My guess is most people seeing the chart will guess that's what it means Zeonglow (talk) 10:08, 3 April 2011 (UTC)

Blue for boys and pink or red for girls is not only a western convention, but also common in the far east, so I would suggest someone with the appropriate skills recolor the lower maps to match the blue=male/red=female convention of the upper one.CharlesHBennett (talk) 16:06, 6 October 2011 (UTC)

South Korea should also be green for the same reason as Australia. — Preceding unsigned comment added by (talk) 06:35, 28 October 2011 (UTC)

X- vs. Y chromosome mass as explanation of the sex ratio difference[edit]

In an undergraduate genetics class, the professor claimed the mass of the XX (female) vs XY (male) was a reason for birth of on average 5% more males. I think this claim has some merit.

155,270,560 nucleotides are in the X- chromosome 59,317,006 are in the Y. (source:

As I was searching for the weight of a human sperm, 2 low quality websites also made the claim (and one saying it is the only reason), which doesn't make me any more confident. Perhaps it can be deduced just by thinking about it, but I'm trying to locate a mass difference and determine if it is actually significant.

So the XY is about 95 million base pairs lighter.

I found the mass of each nucleotide contributes 660 daltons and 0.54nm length (Biochemistry By Reginald Garrett, Charles M. Grisham - google books) (wow, 1.62 meters, our DNA in one cell is taller than we are. The same professor said it was 8 feet, guess he was right about that).

660 x 95,000,000 = 62.7 billion dalton = 0.1 picograms.

% of DNA haploid total (23 chromosomes): 3.2 picograms

3% weight difference in genetic material, so XY sperm are 3% lighter. Could easily explain the ~5% difference. Even water at the microscopic level is like gel, so racing through that stuff, lighter ones should come out ahead more. —Preceding unsigned comment added by (talk) 20:36, 11 May 2011 (UTC)

However, most such factors would be expected to be compensated for over time by Fisher's principle selection pressure... AnonMoos (talk) 21:07, 11 May 2011 (UTC)

Article states:

This difference could be accounted for by the mass difference in Y vs. X- carrying sperm.[citation needed] Sperm with Y (male) are 3% lighter (about 0.1 picograms out of the total 3.2 or 3.3pg mass of entire 23 chromosomes). The 3-10% more males born could be a result of lighter sperm occasionally being first to the egg as they may achieve, on average, more velocity through the thick fluid.

To my knowledge, there is no actual evidence that differences in sperm weight account for the sex ratio at birth. At best, sperm weight is one among many other factors. There is a wealth of data indicating that many other factors affect sex ratio at birth, including for example exposure to ionizing radiation, exposure to teratogens that affect male and female embryos and fetuses differently, and various other environmental stressors. I would strongly suggest removing this assertion. At minimum, produce a credible authority. Eperotao (talk) 01:35, 30 May 2011 (UTC)

Kristof and WuDunn[edit]

An anonymous poster inserted the following:

According to Nicholas Kristof and Sheryl WuDunn, two Pulitzer Prize-winning reporters for the New York Times, violence against women is causing gender imbalances in many developing countries. These authors report that more girls have been killed in the last fifty years, precisely because they were girls, than the number of males who were killed in all the wars of the 20th century. They detail rampant gendercide in the developing world, particularly in India and Pakistan. Besides the dramatic loss of human life, the authors describe a socioeconomic disaster that is resulting in developing countries because of this gendercide. The authors posit that it is impossible for countries to climb out of poverty if only a fraction of women (9% in Pakistan, for example) participate in the labor force. From their personal observations, Kristof and WuDunn note that the most dreadful suffering has happened in the daily lives of poor, mostly village women in certain countries in Africa, Asia and the Middle East. Based on their own extensive interviews, the journalists report that women in some countries may be gang-raped if they leave the house, beaten daily, sold into brothels or married off as little children.

This content, while interesting and of concern, has several issues:

  • It is irrelevant to Human Sex Ratio article. What do the following have to do with an article on Human Sex Ratio: "beaten daily, sold, married off, gang raped, generic claims about village women in certain countries, assertions about climbing out of poverty if a fraction participate in labor force"? These are certain points of view and opinions inconsistent with the topic, its theme, WP:NPOV policy. It may belong on some other wiki page if rewritten with neutral point of view.
  • I have read the source, but failed to find sentences or collection of paragraphs that support the summary as written above. Kristof and WuDunn are careful writers, they do not write those words, or paragraphs that can be summarized as above. Therefore, this paragraph violates wiki's verifiability and WP:NOR policy. The author is encouraged to summarize within WP:NPOV and WP:NOR guidelines while respecting the context of this Human Sex Ratio topic; the author should also eliminate generic claims such as "certain countries" with specific names of countries. Alternatively, the author is urged to mention the page numbers that support this text. Thank you, ApostleVonColorado (talk) 17:15, 14 August 2011 (UTC)

Please contact/talk with wiki editor User:Smyth for some of the previous edits to Kristof and WuDunn section. On 22 July 2011, User:Smyth removed many of the sentences that were re-inserted on 14 August 2011 without explanation by anonymous author mentioned above. User:Smyth's reason for edit: content was irrelevant (see View History for the article). I concur with wiki editor User:Smyth: content such as "impossible for countries to climb out of poverty..." is irrelevant to an article titled Human Sex Ratio. Such content, when presented in NPOV and without synthesis/OR, may belong to some other articles, such as Domestic Abuse, Domestic Violence, etc. ApostleVonColorado (talk) 19:38, 14 August 2011 (UTC)

This article is about plain numerical sex ratio, not sexual inequality in general. To put it bluntly, if it involves females actually dying or being aborted, it's relevant to this article. If it involves females being excluded from the labor force, or having desperately unpleasant lives, it belongs in some other article. – Smyth\talk 17:42, 15 August 2011 (UTC)

Anonymous user with two IP addresses, one being, posted the following allegation on my talk page, as his or her reasons for deleting previous version: The reason after this article was noticed and you came to protect the islamic countrys, are telling and very wrong. i understand than the koran tell you to protect islam in every way posibble but thats not democratic or just to hide the facts from the book about the reasons for this, the article also is not only targeting islamic countrys, but your edit only targets non islamic countrys.

My response: I do not understand your allegation. Allow me to assume you mean well, and you want to contribute facts and issues of importance to this wiki page. Please do not use your energy to make stereotype allegations such as those. Rather, please do use your energy to find verifiable, relevant content to this wiki article written with NPOV. By all means, I encourage you add data on countries from all religions, regions, countries, ages, whatever. But keep it relevant. Reveal the verifiable facts, the truths from everywhere - do so without original research, without a biased point of view, in accordance with Wiki policies. ApostleVonColorado (talk) 17:18, 16 August 2011 (UTC)

List of sex ratio by country/region[edit]

The following content was added on 18 August 2011 by Loyalgirl38:

India’s child sex ratio dipped tremendously – the worst since the country’s independence but the overall sex ratio of the country has increased only marginally – from 933 (2001) to 940 (2011). However, according to the Registrar General of India’s (RGI) records, some big countries across the globe have reported a sharp decline in the number of women. China is a case in point. The country’s sex ratio in 2001 was 944, and it fell to 926 in 2011. Bhutan’s sex ratio saw a major drop: from 919 in 2001 to 897 in 2011. America’s sex ratio also fell from 1,029 in 2001 to 1,025 in 2011.

This section was deleted because it is unreliable/harmful, and because it does not belong in this section.

It is unreliable and harmful because a check of claims made with data from US Census office ( confirms claimed stats for United States are wrong. The cited source is some web article, and it does not identify the "RGI" document and pages that would allow wiki editors to check the calculations and data sources for claims on China, United States, Bhutan and even India. I have 2011 census stat data on India and other countries, and even there the data I have from the source suggests unverifiable claims were made in the cited website. The author is requested to identify RGI pages or tables that confirm the claimed data for China, US, Bhutan and India over 2001 and 2011.

This section is about "list of sex ratio..."; the added content has nothing to do with the intent of this section.

The author is welcomed to add content in appropriate section, per WP:SOURCES guidelines, after she or he has researched the original sources, such as US Census Office or India's Census Office or China's Census Office, calculate the sex ratios, then post with a neutral point of view (avoid using terms like tremendously / worst / big countries / sharp decline / etc - because these are POV words and these are not encyclopedic collection of neutrally presented facts).ApostleVonColorado (talk) 20:51, 18 August 2011 (UTC)

Social Factors[edit]

The following content has been added to this section: The 2011 India census reports India's sex ratio in 0-6 age bracket at 1.094, significantly above the mean ratio recorded in the United States from 1940 through 2002 (1.051), as well as ratios observed in most developed countries in 1999-2002 (1.04 to 1.06).

I am unable to verify from cited reference that the ratio in "most developed countries" was 1.04-1.06 in 1999-2002. Please identify which page or table or figure suggests this. Alternatively, please provide alternate reference for verification. The cited reference is United States data. Claiming United States data as data for "most developed countries" is extrapolative original research, inconsistent with WP:NOR and WP:SYNTH. The cited reference neither compares nor claims 1.094 as significantly above, or statistically insignificant number than the mean and ranges published in the citation for entire population and for various ethnic groups in the United States.

Second, it would be better and more useful to wiki readers, if the data is compared on same year basis. That is, compare birth sex ratio in 2011 in India or whatever country, with birth sex ratio in 2011 in the USA or another country. Comparisons of 2011 data with 1940 or 1999 data is like comparing apples to oranges. For what it is worth, many countries such as Switzerland/Ireland/Sweden/etc report their birth sex ratio between 1.06-1.08 for 2007-2011 period. These same countries note a significant variation in their birth sex ratio between 1990s and 2000s.

Thirdly, for WP:NPOV, a complete summary is encouraged - one that compares mean as well as the range provided by the cited reference.

Lastly, is this content relevant to the section titled social factors? ApostleVonColorado (talk) 12:39, 8 September 2011 (UTC)

Gender balance of Georgia (republic of).[edit]

Gender balance of Georgia (republic of). In the first paragraph Georgia is clearly shown to have more women than men, but in the gender imbalance section it states that Georgia have a higher male ratio. perhaps I misunderstand but this seems incorrect. Clarify? — Preceding unsigned comment added by (talk) 11:11, 8 November 2011 (UTC)

Map needs changing[edit]

The colour scheme is confusing as hell. The CIA one seems most logical - well, if you buy pink=female, blue=male anyway. At a bare minimum, the maps below it should not use the same colour scheme to mean the *opposite* thing.--Fangz (talk) 01:46, 9 December 2011 (UTC)

Agreed. It's a complete muddle the way it is now. All maps should use blue for male and red/pink for female. (talk) 13:31, 11 July 2012 (UTC)

Breast Cancer Death NOT specific to females[edit]

I have removed the words "breast cancer and " from the listing of "causes [of death] specific to females". Although breast cancer is found far more in females than males, and breast cancer results in far more female deaths than male deaths, it is not specific to females only. There are many references to this, but for two quick ones, see: and Kmasters0 (talk) 09:41, 28 November 2012 (UTC)


Am I completely crazy or is this just wrong?:

Human sex ratios, either at birth or in the population as a whole, might be quoted in any of four ways: the ratio of males to females, the ratio of females to males, the proportion of males, or the proportion of females. If there are 80,000 males and 100,000 females, the ratio would, respectively, be quoted as 1.25, 0.8, 0.519 or 0.481. Sex ratio in scientific literature is often expressed as the proportion of males. In contrast, sex ratio quoted in this article is the ratio of males to females, unless specified otherwise.

Ratio of males to females is 1.25? These seem to me to be wrong. Apologies if I am incorrect. — Preceding unsigned comment added by (talk) 15:14, 5 May 2013 (UTC)

100,000/180,000=0.556 -- AnonMoos (talk) 17:39, 5 May 2013 (UTC)

Ratio over time?[edit]

Hi, does anybody have some data how the ratio between females and males varied over time? I have now read multiple times that polygamy was often allowed as there was a huge excess of females due to warfare etc. and therefore a monogamy would have left multiple women without men. Is there any data supporting this or are these claims just plain wrong? (talk) 00:37, 11 August 2013 (UTC)

Serious math error in lead section[edit]

There appears to be a serious error in the first paragraph of the lead section where it says: The sex ratio at birth is commonly thought to be 107 boys to 100 girls,[2]..." The source given is the CIA Fact Book, but when I went to the source, the ratio at birth was given as 1.07 male(s)/female. Should I simply correct this error? I'll paste in the link to the source page:

Sorry, I'm not seeing any error here. The two figures (107:100 or 1.07:1) are just two different ways of expressing the same ratio, both equally good and in agreement with the source: Noyster (talk), 19:51, 24 November 2014 (UTC)
No, the error was mine. I deleted this comment, but someone restored it. Bwark (talk) 21:47, 30 November 2014 (UTC)


Someone has recently called for an infobox to be added, but does anyone have a suggestion for the style of infobox to be used, as I'm not seeing anything suitable here: Noyster (talk), 10:15, 14 January 2015 (UTC)

Noyster, as you can see here, it was The Vintage Feminist who requested an infobox. I and others also had a discussion with The Vintage Feminist about requesting infoboxes. I don't see that the Human sex ratio article needs one. Flyer22 (talk) 10:35, 14 January 2015 (UTC)

The map is inaccurate[edit]

It says many countries, such as Australia, have more female than males. According to the CIA factbook the article cites, Australia has 1.01 males per female I think the map was just assuming first world countries have more females than males as a rule, but the reason many do is because of lopsided population sizes of generations; e.g. there are more women age 64+ and if the largest generation is 64+ there will be more women. First world countries without a large baby boom would have more balanced populations or populations where men outnumber women because the younger generations are larger. Brianc26 (talk) 22:23, 31 January 2015 (UTC)

Probably because the map was compiled in 2006 - as the reference says - but the current World Factbook is giving estimates for 2014. The maps need updating and it's not clear either why we need two different maps for the total-population ratio: Noyster (talk), 11:31, 1 February 2015 (UTC)

Color unification[edit]

The first map shows countries with "more boys" as blue, while later maps show "more boys" in red. This is obviously confusing for a casual reader, and could be fixed with a color replacement tool, I suppose.--Paxik (talk) 09:22, 27 April 2015 (UTC)

 Done. But my experience is that when I upload to Commons an image modified from one already at Commons, it often gets deleted by the admins there. If that happens to this map, someone will need to revert my edit to Human sex ratio. Maproom (talk) 20:39, 2 October 2016 (UTC)

Ionizing Radiation ?[edit]

I wonder why ionizing radiation as a possible sex ratio determinant is missing in the article despite a wealth of literature about this issue, starting with Muller's famous animal experiments (awarded with the Nobel prize) and with Schull's and Neel's work on genetic outcome in humans after Hiroshima and Nagasaki. Does this eventually reflect an overall pro-nuclear bias of WIKIPEDIA? For recent work containing related references see: [1] [2].Hscherb (talk) 12:26, 16 November 2015 (UTC)

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Effects of gestation environment[edit]

Cite 25 appears to be inconsistent whether malnutrition or obesity lowers the male/female birth ratio.

It states:

"Short maternal stature and obesity were independently related to a low sex ratio at birth." and also "These results are consistent with animal experiments that indicate an adverse effect of maternal malnutrition on male fetuses."

Link to abstract [3]

Consequences are overly speculative[edit]

The article currently reads "There is evidence that this situation will lead to increased levels of antisocial behavior and violence and will ultimately present a threat to the stability and security of society.", which is unsupported by the linked article's abstract[4]. The linked article's abstract makes no claim about antisocial behavior (outside of the violence it discusses), the stability or security of society, and scopes its discussion of violence to violence against intimate partners. The paragraph could be rephrased to "There is evidence that this situation is linked to increased violence by males against female intimate partners." The preceding sentences also need review, as they appear to be unsupported. (talk) 17:45, 25 August 2017 (UTC)

There's been a lot of speculation on the effect of "bare branches" on Chinese society, etc. AnonMoos (talk) 01:50, 27 August 2017 (UTC)