Talk:Fertility and intelligence/Archive 1

Total fertility rate and educational attainment
Total fertility rate and educational attainment is slightly off topic, despite being correlated. I wonder if it might be made a separate article or a separate section of Total fertility rate? Walter Siegmund (talk) 19:43, 30 June 2008 (UTC)


 * Actually, there are more articles on total fertility rate and educational attainment than for fertility rate vs intelligence. I believe it would help expand the article to adopt an approach of fertility rate vs education.--Ramdrake (talk) 19:54, 30 June 2008 (UTC)


 * Renaming the article 'Education and fertility' would result in the deletion of a significant part of the content which wouldn't expand the article, hence the logical thing to do would be to create a 'fertility and education' article. --Zero g (talk) 20:04, 30 June 2008 (UTC)


 * What about merging the content with Total fertility rate? It could use additional content. Walter Siegmund (talk) 21:19, 30 June 2008 (UTC)


 * Maybe with Demographic-economic paradox??--Ramdrake (talk) 19:44, 1 July 2008 (UTC)


 * The Total fertility rate article isn't about correlations and seems more of a standard to measure the reproduction rate of a population, so merging would invalidate most sources for not being relevant to the article. The Demographic-economic paradox is about Fertility and GDP which would invalidate most sources per WP:SYN.
 * May I inquire about the motivation behind the desire to merge? The article is developed enough to stand on its own. --Zero g (talk) 21:02, 1 July 2008 (UTC)


 * It seems to me that a single article that integrates related content and provides a context for that content may be preferable to multiple articles with the same information but with redundancy, contradictions and poor integration. I think this view is consistent with the WP:SUMMARY guideline of allowing articles to grow until there is enough text in a given subtopic to merit its own article.


 * I think adding a section to Total fertility rate with a title "Factors affecting fertility rates" would improve that article. I don't think it fits as nicely with the "Demographic-economic paradox" article, although it is related. Walter Siegmund (talk) 22:00, 1 July 2008 (UTC)


 * I was thinking of the Demographic-economic paradox because one of the main explanations for the differential fertility rate on is the economic situation (socioeconomic status) of the individuals. But I'll stick with whatever consensus comes out of this.--Ramdrake (talk) 22:09, 1 July 2008 (UTC)

(un-indent) We should treat everything here. There is a problem of simultaneous casualty between education (intelligence) and income (when one increases the other one increases.) If this was not dealt with in the sources provided (which I doubt, since data on intelligence sucks) then I am less than impressed with them and will attempt to find better stuff on economic journals. I dont really care if you live the racial stuff in there, but I do care that we include an economics sections (even if small) arguing the case that this correlation, when obtained across populations, may very well be a symptom of the fertility transition. Brusegadi (talk) 08:15, 4 July 2008 (UTC)

There is a very large problem with this data. Rather than testing fertility, they measured the number of children. This is very poor methodology and provides flawed and misinterpreted data. —Preceding unsigned comment added by 71.205.249.224 (talk) 00:37, 12 November 2008 (UTC)

Potential Sources
According to Ramdrake as taken from the dysgenics article, the following source might be interesting for the article, if anyone can access it. ''A negative correlation between fertility and IQ has existed in many parts of the world at various times. Ref: Literacy, Education and Fertility, Past and Present: A Critical Review, Harvey J. Graff'' --Zero g (talk) 19:22, 1 July 2008 (UTC)
 * Graff (1979) looks like a good source, but it was published in 1979 and I'm sure that a great deal has been published since then. I see that it cites papers on fertility in Egypt, Barbados, China, Taiwan, India, and Latin America, as well as Victorian England and the United States since the Civil War. I didn't see any reference to IQ or intelligence, only literacy and education. Walter Siegmund (talk) 21:35, 1 July 2008 (UTC)


 * Yes, it is about fertility and education. I believe that the article already makes the point somewhere else that education is a good proxy for IQ. If you feel that statement needs additional reinforcement, let me know and I will find additional material.--Ramdrake (talk) 21:38, 1 July 2008 (UTC)


 * I remember that Harkenbane cited a correlation coefficient of 0.5 and characterized that as a good correlation in his contribution that I criticized as OR. That said, I think it is fine with the Graff (1979) source. It is a minor point that I would not expect to be the subject of much controversy. Walter Siegmund (talk) 22:09, 1 July 2008 (UTC)
 * Yes, 0.5 is considered a good correlation, FWIW.--Ramdrake (talk) 22:11, 1 July 2008 (UTC)


 * I don't have any problems with it if it's properly explained in the article. --Zero g (talk) 00:36, 2 July 2008 (UTC)
 * Just checked, it's there and it's sourced.--Ramdrake (talk) 00:54, 2 July 2008 (UTC)

fertility and income
Are there any good sources that compare 'fertility and intelligence' to 'fertility and income' ? From what I gathered income is correlated to intelligence and conscientiousness, but I am not aware of any research that tries to pick apart which correlation (intelligence, income, education, conscientiousness) has the greatest/most causal influence on fertility. --Zero g (talk) 02:28, 2 July 2008 (UTC)
 * I'll see if I can find any. Most would argue that intelligence is a function of education which itself depends on income.  Then you obtain a simultaneous casualty where increments in one cause increments in the other so you get a positive feed-back loop with diminishing increments (so both quantities converge).  The only problem is that reliable data on education is faulty, not to mention reliable data on "intelligence."  Brusegadi (talk) 08:19, 4 July 2008 (UTC)
 * I think recent research has shown that the belief that education increases IQ is incorrect, given g becomes increasingly heritable with age. I would assume high IQ increases the chance of a college degree, which in turn increases the chance of a high income.
 * Next there is the issue that IQ and fertility mainly affects women, so studies that only sample women are likely to over-represent the correlation by up to 200%.
 * I'll leave the 'what is intelligence and how do you measure it' discussion to the IQ article. --Zero g (talk) 01:42, 5 July 2008 (UTC)
 * There's no doubt that education increases IQ, I don't think even the most extreme hereditarians would deny this. If you can find any reliable source to support your claim then I'll be extremely impressed. I read recently that in a study of identical twins separated in infancy, an average of five years difference in education lead to an average ten point difference in IQ, with the most extreme case being a 14 year difference in education producing a 24 point difference in IQ between one twin pair. I'll leave you to guess which twin had the higher score. I'll check the source for you if you like. Furthermore it is a well known fact that practicing IQ tests makes one better at IQ tests, so one can train oneself to have a high IQ with practice. Alun (talk) 13:20, 7 July 2008 (UTC)
 * A difference of 24 points between one twin pair has no use, other than to awe a preconceived mind. Please cite this study, or one decent study that shows that education or a high SES environment increases IQ (g) significantly into adulthood, since IQ gains from education tend to fade, as noted in the bell curve. --Zero g (talk) 13:51, 7 July 2008 (UTC)
 * Here: --Ramdrake (talk) 14:25, 7 July 2008 (UTC)
 * "children born to high-SES parents score higher than children born to low-SES parents" I was asking about a study showing adult scores, one would think the scientific community would be eager to disprove the bell curve, but that doesn't seem to be the case. The source however seems to indicates that by age 16 nature already dominates nurture. --Zero g (talk) 14:44, 7 July 2008 (UTC)
 * Actually Zero g you haven't responded correctly to my post, I wrote that an average 5 year difference in education lead to an average ten point difference in IQ for a study of identical twin pairs reared apart, the single twin pair you selectively point to was only the most extreme example, but followed the trend that longer time spent in education significantly increases IQ scores. The source is "Nature with Nurture: A reinterpretation of the evidence" by Urie Bronfenbrenner in Race and IQ edited by Ashley Montagu. The quote is "For example of the 19 pairs of separated twins in this study, there were 8 pairs who had the same number of years of school; the average IQ difference for this group was 1.45. The remaining 11 pairs differed in amount of schooling for an average of 5 years; the corresponding average difference in IQ points was 10.4. The greatest single pair difference in schooling was 14 years with an IQ difference of 24 points. Since all are identical twins, these differences in score cannot be genetic in origin and are therefore the product of varying educational environments. Accordingly, Newman, Holzinger, and Freeman (1937) conclude from their data that 'differences in education and social environment produce undeniable differences in intelligence'" Likewise you still seem to be hopelessly confused about heritability. The fact that heritability rises with age is no more than an indication that adult environments are more homogeneous than those of children. Remember that heritability is a meaure of the proportion of the variation in a population that is attributable to genes, it is not a measure of the absolute contribution of genes to the variation. Therefore if adult environments are more homogeneous that childhood environments, as there is some evidence to suggest, then the contribution of genes to the variation in IQ will increase, even though the absolute contribution of genes to the variation has not changed. Alun (talk) 15:59, 7 July 2008 (UTC)
 * One other observation, Zero g is claiming that education does not increase "intelligence", well if we accept this for the sake of argument, then he must believe that the increase in the average IQ in modern populations that has been well documented over recent years (the Flynn effect) must be primarily due to genes, in which case it would be prima facie evidence against dysgenesis. Indeed the argument of Lynn in that the Flynn effect is the product of education and this better education is an environmental effect on intelligence that is masking the genetic intellectual dysgenesis of the population that he purports to document. So even proponents of dysgenics support the idea that education is increasing measured intelligence in the form of IQ. If Lynn were to claim that education has little or no effect on IQ, then he would have to admit that the Flynn effect is due to selection for better "intelligence" genes in the population, which would be evidence against dysgenesis. It can't be true that education has little or no effect on IQ and that IQ is going up and that dysgenesis is occurring, these are mutually exclusive claims. Alun (talk) 09:24, 8 July 2008 (UTC)


 * Your study is from 1937 with no indication of the age upon which the test was taken, that education was the main variable, and that the test was g loaded. You'd readily discard this as bad science if you didn't happen to like the results.


 * The flynn effect is possibly less pronounced when adults are measured, not to mention that most of the gains are in the lower end of the distribution. Not to mention there is a variety of alternative explanations to the Flynn effect. People have gotten taller, and height is correlated with IQ. --Zero g (talk) 15:01, 9 July 2008 (UTC)


 * Zero g, historical gains in height are correlated with historical gains in IQ. I'm not aware of any direct correlation of height with IQ in the general population (except in children with development disorders, of course). Also, please supply sources for the supposition that the flynn effect is possibly less pronounced when adults are measured, as I don't see this being supported anywhere in the literature.--Ramdrake (talk) 15:48, 9 July 2008 (UTC)
 * Hmmm, thats interesting Zero g, because historical gains in hight (in England) are strongly correlated with better income and nutrition for the youngsters. It turns out that as soon as most did not have to work 16 hour days at the factory, they grew taller.  Now I know they also got "smarter" (IQ up).  We cant say much about this type of correlation, one improvement (income) can be driving changes in all of them (height, IQ.)  Brusegadi (talk) 03:01, 10 July 2008 (UTC)

(unindent) What are you talking about Zero g, the paper I'm citing is from 1974, it was written for Ashely Montagu's "Race and IQ", that paper itself cites a source from 1937, but unless you are claiming that there was a fundamental difference in monozygotic twins in 1937 compared to today, then I don't see what your point is. The 1937 study is interesting because it is one of the few studies of monozygotic twins where some of the twins were reared in very environmentally diverse families. It's a weakness of MZ twin studies that the twins tend to be put in very similar environments, so we see environmental correlations. When we look at twins that have very different educational backgrounds it provides evidence that the IQ differences are significantly affected by education. As for gains in height, well it further undermines the hereditarian argument. Indeed the height comparison is often used to show that within to between group differences cannot be inferred from heritability estimates. The heritability of height is ~90% i.e. people with tall parents tend to be tall within the population measured, but the average height in Britain 100 years ago (one population) was much less than the average height today (a different population), this is put down to better nutrition. The chances are that the families with "tall" members in say 1900 still have atll members relative to the populations they live in, but that all families within this population are taller than their ancestors within the older populaton. If better nutrition can lead to a dramatic effect on height even though height has a much higher heritability than IQ, then it stands to reason that education can also have a dramatic effect on IQ even if it is highly heritable. I don't know anyone (besides you) who disputes the Flynn effect. Likewise the increasing heritability of IQ with age is something we would not expect to see if a trait or character, such as IQ is primarily under genetic influence, we would expect it to be the other way arround, with high heritability in infancy and low heritability in adulthood. You really are confused about heritability. Let me make a point, a characteristic can be totally due to genetic factors and have a low heritability and a characteristic can be totally due to environmental factors and have a high heritability. Heritability does not meaure the effect of genes on a characteristic. This is the classic mistake of hereditarians, they think that a high heritability means that the characteristic must be primarily under genetic control, this is a fallacy. Heritability measures what proportion of the variation can be accounted for by genes. Ned Block gives the example of digit (fingers and toes) number in humans. The number of digits in humans is genetically predetermined, our genes say five per limb, so we get five. When variation occurs it is nearly always down to environmental conditions (e.g. taking drugs during pregnancy), so the heritability (ie the variation in finger number) is low for finger number in humans, because the variation is mainly caused by environmental effects, but finger number is always genetically predetermined to be five. So heritability does not measure the effect of genes on a trait, it measures the effect of genes on variation of a trait within a population. The misuse of heritability by so called "scientists" who have a (usually) racist axe to grind is well known, it's no accident that most geneticists think of heritability as a quite useless statistic. Mostly you now appear to be giving your own personal opinions, and your posts don't seem to be relevant to improving the article. Keep it about the article, and keep it about citing reliable sources. Alun (talk) 06:29, 10 July 2008 (UTC)

Idiocracy
This was pretty much the entire point of the movie Idiocracy, at least, it was the entire point of the intro, and set up the rest of the story. Should there be a reference here? 216.6.128.244 (talk) 18:15, 28 July 2008 (UTC)

I was just about to put one in before I saw this talk page, so I will, with the title "In popular culture" —Preceding unsigned comment added by 58.170.120.7 (talk) 05:58, 18 December 2008 (UTC)

Vining

 * In 1982, Daniel Vining sought to address these issues in a large study on the fertility of over 10,000 individuals throughout the United States, who were then aged 25 to 34. The average fertility in his study was correlated at -0.86 with IQ for white women and -0.96 for black women. In considering these results along with those from earlier researchers, Vining wrote that "in periods of rising birth rates, persons with higher intelligence tend to have fertility equal to, if not exceeding, that of the population as a whole."

This section looks odd for two reasons: the negative correlation is implausibly large (it suggests that almost every low IQ woman has more children than almost every high IQ woman); and if true is exactly the opposite of the Vining quote which follows.--Rumping (talk) 11:11, 23 September 2008 (UTC)


 * Yes I agree. This section is misleading. I just reviewed Vining's (1982) actual paper and could *not* find the claimed high negative correlations (-0.86 and -0.96) between fertility and IQ reported in this section. This must be a mistake, and should be corrected. The largest negative correlations I found in Vining's (1982) paper, were more in the -0.15 to -.20 range, which is actually consistent (rather than inconsistent) with Vining's quote which follows in the next section. —Preceding unsigned comment added by Eplebel (talk • contribs) 04:25, 11 April 2010 (UTC)

Validity

 * The Citation for the article refers to a Study correlating number of children born to individuals and IQ. All results in this article are invalid. The studies showed that the lower somebody's IQ, the more they reproduced. That data was in fact collected. However, it was collected from a subset of data that would clearly not be indicative of the world populace as a whole. Moreover, we have known for years that lower income families tend to have more children than high income families, and that in general people with higher IQs tended toward higher income. The problem there, is that there are legitimate sociological effects that influence the result such that the genetic factor is rendered void; vis a vis, availability and proliferation of prophylactics, proper prophylactic education, race, neurological factors independent of fertility, physical damage altering fertility, social stigmata associate with procreation, et al. There are too many factors to list to even attempt to correct this data. We have the technology available to test the ability of an individual to produce children without attempting to explain it sociologically.

In conclusion, this data is valid, however it does not provide evidence to the conclusions assigned to it. This article should be removed immediately. 24.23.71.163 (talk) 06:17, 4 January 2009 (UTC) Jeremy Cape

See the Fertility vs. Fecundity section I just added. It addresses much of your comment. The objection that the article mostly only addresses research in the United States is valid and accurate. Please be more careful with generalizations (e.g., "All results in this article are invalid.") in the future, since, after all, all generalizations are false. --Jtoomim (talk) 17:46, 11 March 2009 (UTC)

Fertility vs. Fecundity
There seems to be a common misunderstanding that's prevalent among Wikipedians regarding the term "fertility." When used in non-demographic contexts, it refers to the biological ability to produce offspring. However, in demographic contexts, fertility means the actual production of offspring (or, if you prefer, the ability to produce offspring when taking behavioral and social factors into account); when demographers describe the ability to produce offspring when ignoring behavioral factors, they use the term "fecundity." See: http://www.gfmer.ch/Books/Reproductive_health/The_demography_of_fertility_and_infertility.html, http://www.enotes.com/public-health-encyclopedia/fecundity-fertility. Unforunately, neither Fertility and intelligence nor fertility make this distinction clear enough. Several contributions to both the article and the discussion pages evidence this common misconception--in particular, 24.23.71.163's second edit (adding the 'family size, not fertility' proviso--mean family size is almost identical to demographic fertility). I currently plan on making a few changes: one, removing Jeremy Cape's (24.23.71.163) 'family size' provisos; two, changing the fertility link to a fertility#demography link; and three, adding an explicit distinction in fertility#demography between the demographic terms fertility and fecundity. I think it might also be a good idea to add a sentence to the main article on the distinction, but I don't know where that should go. I realize that there already is a sentence in the first paragraph that states that the correlation refers to the total fertility rate, but the fact that editors are still confusing it is evidence to me that it's not enough. --Jtoomim (talk) 17:46, 11 March 2009 (UTC)

Move?

 * The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section. 

The result of the proposal was Not done. (abandoned incomplete request) DMacks (talk) 04:05, 22 September 2009 (UTC)

Fertility and intelligence → Birth rate and intelligence &mdash; —Preceding unsigned comment added by 12.109.151.104 (talk • contribs) 20:24, 2009 September 14 (UTC)


 * Please state your reasoning. With no justification, it is likely that this request will be closed and no action will be taken. Walter Siegmund (talk) 21:20, 14 September 2009 (UTC)


 * The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Question on Vining study
In the "Early research" section, the fourth paragraph says that Vining found that "in periods of rising birth rates, persons with higher intelligence tend to have fertility equal to, if not exceeding, that of the population as a whole" -- that is, either a neutral or a positive correlation between IQ and fertility.

However, the next paragraph states that a follow-up study found "the same, though slightly decreased, negative correlation between IQ and fertility." This seems like a contradiction.

If the second study found a negative correlation, then the findings were not the "same" as the first study (which did not find a negative correlation) and the wording should be changed. Could someone please explain this to me? --Cerebellum (talk) 01:07, 29 March 2010 (UTC)

I agree, I spotted this and it makes no sense. Similarly, the article says Lynn's study found a correlation of (almost) zero, yet the article implies this supports Vining's result, which it doesn't Ben Finn (talk) 16:24, 12 April 2010 (UTC)

that's racist
I know what you're implying, and that's racist.


 * May I ask what is racist? Spitfire 19 (Talk) 14:09, 27 April 2010 (UTC)

There is nothing racist here, so get over yourself. —Preceding unsigned comment added by 213.109.230.96 (talk) 09:39, 7 May 2010 (UTC)

Intelligence Citations Bibliography for Articles Related to IQ Testing
You may find it helpful while reading or editing articles to look at a bibliography of  Intelligence Citations, posted for the use of all Wikipedians who have occasion to edit articles on human intelligence and related issues. I happen to have circulating access to a huge academic research library at a university with an active research program in those issues (and to another library that is one of the ten largest public library systems in the United States) and have been researching these issues since 1989. You are welcome to use these citations for your own research. You can help other Wikipedians by suggesting new sources through comments on that page. -- WeijiBaikeBianji (talk) 17:16, 8 July 2010 (UTC)


 * It's high time for this article, among several articles on related topics, to refer to more reliable secondary scholarly sources and fewer primary sources (or popular culture sources). Right now, the article doesn't really give proper weight to mainstream professional literature on this topic. -- WeijiBaikeBianji (talk) 16:35, 19 October 2010 (UTC)

What about Freud?
What about Sigmund Freud's linking of intellectual to sexual curiosity (see his Three Essays on the Theory of Sexuality), as well as his theory of sublimation of unused or repressed sexual energies by channeling them into "more worthwhile" intellectual and/or artistic activities? No connection to the topic discussed by the article? Also, might the blonde stereotype figure into what the article looks like as of now?

Also, I harbor the suspicion that if Freud's rather non-reductive concept of sexuality (as he definitely doesn't reduce it to mere reproductive activities) is of no concern here, it's because this article should REALLY be at Birth rate and intelligence instead as somebody suggested above. --79.193.29.76 (talk) 15:46, 28 October 2010 (UTC)

Erroneous criticism of Richard Lynn's book "Dysgenics"
The Criticisms subsection of the article is misleading. It cites an article by Steve Connor that was published a week before Richard Lynn's book was released that claims that "A flaw in his argument of genetic deterioration in intelligence was the widely accepted fact that intelligence as measured by IQ tests has actually increased over the past 50 years" giving the false impression that Lynn has ignored the issue of the secular rise in IQ, when anyone who has read his book would know full well that he had devoted a whole chapter to the issue. In Chapter 8: Resolving the Paradox of the Secular Rise of Intelligence, Lynn points out that the rapid secular rise in phenotypic intelligence brought on by environmental improvements would mask the much slower decline in genotypic intelligence, but that we cannot count on environmental improvements forever increasing phenotypic intelligence, as there will likely be diminishing returns.

Lynn's critics should really know better. Anyone who had actually read his previous work would've known he was aware of the secular rise in intelligence, because he himself had previously published research documenting it. Hell, anyone who has read James Flynn's work would know that Lynn is aware of the secular rise in IQ, as Flynn cited Lynn's work on it in his book Asian Americans: achievement beyond IQ and in his published work in peer-reviewed journals such as Massive IQ Gains in 14 Nations: What IQ Tests Really Measure from Psychological Bulletin.--B.B. (talk) 07:31, 8 April 2011 (UTC)

Merge discussion

 * Propose merge. This has been a central theme - arguably the central theme in Eugenics from the outset. There is no sense in it occupying an article on its own. Itsmejudith (talk) 09:44, 8 April 2011 (UTC)
 * Comment It has been suggested that this article be merged with Eugenics. --Walter Siegmund (talk) 04:26, 13 April 2011 (UTC)
 * Keep separate The relationship between fertility and intelligence is logically separate from eugenics. That there is such a relationship does not necessarily mean that there must be eugenics. Furthermore, even if the relationship between fertility and IQ was such that IQ was increasing worldwide, it would still be possible to argue for eugenics in order for this to happen quicker. Similarly, eugenics can be argued using other arguments such as declining genetic health. I finally note that both articles are rather long.Miradre (talk) 10:04, 8 April 2011 (UTC)
 * Support merge - essentially this is a POV fork of Eugenics, though the material doesn't overlap one for one (hence merge, rather than outright delete). Point of note, not everything in this article should be merged, some of the more egregious pov pushing, original research and undue weight stuff should be simply dropped.Volunteer Marek (talk) 05:49, 13 April 2011 (UTC)
 * It there are problems it should fixed regardless. What is incorrect? Miradre (talk) 05:51, 13 April 2011 (UTC)
 * As I've said before, I'm not really interested in having conversations with people like you.Volunteer Marek (talk) 05:53, 13 April 2011 (UTC)
 * That is unfortunate since discussions are part of Wikipedia. You also discussed with me not many hours ago on another topic. So, what is the basis for your claims? Miradre (talk) 05:55, 13 April 2011 (UTC)


 * support merge: this material should be treated in combination with eugenics and I would also propose that the article Dysgenics is best treated atthat main article.·Maunus· ƛ · 13:56, 13 April 2011 (UTC)
 * Keep seperate: This article is simply stating the facts about how IQ is inherited. Eugenics is goverment control of reproduction.--RaptorHunter (talk) 05:09, 21 April 2011 (UTC)
 * Your comments are indicative of how a large number of pages linked to this one are in a bad state.
 * Eugenics is a philosophy and is not based upon government intervention.
 * There are no facts on the Heritability of IQ being presented here Correlation is not causation. A fact requires something that can be validated by evidence ie observation and experimentation.Tetron76 (talk) 12:30, 26 April 2011 (UTC)


 * support merge this is an article that is misnamed. Fertility and intelligence is a false correlation and to include the information as a separate article is highly misleading as an encyclopaedia article. Firstly, fertility is more commonly used as fecundity so the title may mislead many readers. Secondly, "being royal may make you rich but being rich doesn't make you royal", just because in the West better educated / more intelligent people may choose to have fewer children doesn't mean that having fewer children or more abortions makes you more intelligent. Thirdly, there is no reliable IQ test data available for most nations so it is impossible to even reliably measure if there is a correlation between the defined terms. Fourthly, birth rates are also adversely affected by various pollutants that also can have a negative effect on brain development. Finally, There are many other factors that mean that this article contains misleading information and would be better handled within the context of a broader topic.Tetron76 (talk) 12:30, 26 April 2011 (UTC)
 * keep separate This topic is logically separate from eugenics. It could perhaps be merged into some other article(s) though, perhaps Health and intelligence, Fertility, and/or Fertility-development controversy.--Victor Chmara (talk) 17:54, 26 April 2011 (UTC)
 * Fertility-development controversy is a possible location but I think the placement in the other two would be inappropriate (health appears to be wrong since the strongest correlation are to education and fertility covers a much broader topic). The majority of the sources discuss this issue in terms of eugenics or dysgenics.Tetron76 (talk) 10:16, 27 April 2011 (UTC)

Birth order study
This study:. Is about birth order and intelligence. Not about this topic so it should be removed.Miradre (talk) 04:15, 13 April 2011 (UTC)
 * It is about family size more than birth order. Will you argue that family size isn't relevant for the topic of fertility?·Maunus· ƛ · 13:01, 13 April 2011 (UTC)
 * It is a somewhat different topic. The authors argue that having more children does not decrease IQ for later children. This is a different issue from is those with lower IQ have more children. It could be in the article but as a separate topic.Miradre (talk) 13:39, 13 April 2011 (UTC)

Roman decline equals.... fertility?
Ignoring the pretentious, condecsending pseudoscience that comprises this article, the claim that a) a decrease in the intellect of the Roman elite due to lead poisoning caused the decline of the Roman Empire, equates to b) fertility is inversely proportional to intelligence, is patently absurd. Even ingnoring the fact that the former statement is a crackpot theory, the two don't mean the same thing; their fertility levels are irrelevant. 213.29.115.6 (talk) 20:13, 13 May 2011 (UTC)

Intelligent 'have better sperm'
Is there any place for this study in the "Fertility and intelligence" article, which suggest that men with higher IQ's have better sperm quality (see link below). As the article states: "The researchers found that independently of age and lifestyle, intelligence was correlated with all three measures of sperm quality - numbers, concentration, and ability to move. The study, which appears in the journal Intelligence, appears to support the idea that genes underlying intelligence may have other biological effects too.". http://news.bbc.co.uk/2/hi/7767877.stm Sempre30 (talk) 00:05, 21 May 2011 (UTC)

POV tag
This whole article is yet another venue for pushing racist "research" on Wikipedia. This is immediately apparent, starting with the opening sentence which equates "intelligence" with IQ. It then goes on to cherry pick studies to support this notion. It also throws in several discredited Eugenicists and presents their views as fact without even mentioning their background. Overall the article is a textbook case of agenda pushing and violation of WP:UNDUE.Volunteer Marek (talk) 08:27, 8 July 2011 (UTC)
 * I corrected the lead as per your observation. Thanks. Exactly how is the rest of the article not NPOV? What studies and views are missing? Please note that ad hominem is not a valid argument for scientific arguments.Miradre (talk) 08:36, 8 July 2011 (UTC)
 * ...or it may not measure much of anything beside the ability to do well on IQ tests. That's not enough. Which hominem did I ad?Volunteer Marek (talk) 08:50, 8 July 2011 (UTC)
 * IQ test results are highly predictive for future life achievements. But that is the topic for another article. You did not add anything. But you claim here that something is missing for NPOV. What views and studies, exactly, are missing? Claiming that something is POV without giving details is not verifiable and cannot improve the article.Miradre (talk) 08:55, 8 July 2011 (UTC)
 * For starters, the big elephant in the room that hardly gets a mention is the well documented negative relationship between fertility and income. There's additionally no mention in the article (aside from the short phrase you added) that IQ is not generally accepted to be a measure of intelligence. The article glosses over this, immediately skipping to discussing the relationship between fertility and IQ. Unfortunately, this article follows the pattern of most articles in the "Race and Intelligence" area where studies by a couple of "controversial" (to put it politely) "researchers", most of whom are associated with the racist organization the Pioneer Fund are given center stage prominence.Volunteer Marek (talk) 09:01, 8 July 2011 (UTC)
 * If you have sources for you claims regarding income and fertility and that this is relevant, (intelligence likely correlates with both income and ferility) then please add them. However, claims of things without sources is not acceptable according to Wikipedia policies. Ad hominem attacks agains reserachers are not scientifically valid. I will add some further clarification regarding IQ which do is the most commonly used measure by scientists.Miradre (talk) 09:07, 8 July 2011 (UTC)
 * The fertility-income relationship is quite well documented and one of the more robust ones one can find in social science. I can note the absence of discussion - that is enough for me to include the POV tag. I don't have to provide this myself. You can call them "Ad hominem" attacks, but at the end of the day we do make judgement calls - based on reliable sources - about sources and the people who produce them. IQ -as-intelligence is accepted in some (sub) disciplines but not in others.Volunteer Marek (talk) 09:11, 8 July 2011 (UTC)
 * If you do not have a source making the connection with fertility and intelligence you are doing OR which is not acceptable by Wikipedia standards. Yes, it is you who make a claim who have to provide the sources.Miradre (talk) 09:15, 8 July 2011 (UTC)
 * What are you talking about? The article is TITLED "fertility and intelligence".Volunteer Marek (talk) 09:25, 8 July 2011 (UTC)
 * Yes, it is not titled "income and intelligence". If you are making a claim that income is relevant for "fertility and intelligence", then it is you who must provide the source. Otherwise you are doing OR which is not allowed.Miradre (talk) 09:26, 8 July 2011 (UTC)
 * Sigh*. Ok, as I've said the link between income and fertility is well established. Anyone with even a basic knowledge of statistics knows that when examining the relationship between two variables it is necessary to correct for other, correlated, variables. This is all pretty straight forward and is documented in many places including Wikipedia articles. But alright, I will dig out and add some sources in the near future.Volunteer Marek (talk) 09:38, 8 July 2011 (UTC)
 * And btw, there is already some stuff about this in the article. The thing is that this is probably the main reason for this seeming correlation. So it's really that the most likely explanation is tucked away within the article, while research of those like Lynn is given prominence that's the problem. WP:UNDUE.Volunteer Marek (talk) 09:40, 8 July 2011 (UTC)
 * A known link between income and fertility, as well as a link between intelligence (IQ) and fertility, does not automatically man that all three affect one another. They may well be related. Or not. Claiming this without a good source is OR. If you have a source claiming that income is relevant for "fertility and intelligence", then please add it. Any remaining reason for keeping the POV tag? (Ad hominem is still not a scientific argument).Miradre (talk) 09:43, 8 July 2011 (UTC)

<-- Yes, WP:UNDUE as stated above.Volunteer Marek (talk) 09:48, 8 July 2011 (UTC)
 * In order to claim that you must state what is missing which you have not. Simply voicing an opinion without support is not verifiable or constructive. Cannot improve the article. Also, I note that for example this study already controls for economic factors and IQ is still significant: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=5794948 Miradre (talk) 09:51, 8 July 2011 (UTC)
 * Can you provide the relevant sections from this study for verification? Not just the abstract, but the methodology and the results.Volunteer Marek (talk) 10:11, 8 July 2011 (UTC)
 * That is not required per WP policy. Most scientific studies are not free but one must pay to read them. The study itself is a verifiable source. I suggest that you use a library if you wand to read the whole study.Miradre (talk) 10:15, 8 July 2011 (UTC)
 * What I'm wondering is if YOU have actually read the study. Verification is something that can be asked for, especially since it seems like you just did a google search, found an abstract which sound vaguely like what you want and included it. You should not try to add sources you haven't actually read.Volunteer Marek (talk) 10:30, 8 July 2011 (UTC)
 * Do you have actual scientific objections to the study? Miradre (talk) 10:41, 8 July 2011 (UTC)
 * That would depend on what's actually in the study, wouldn't it? So please provide info for verification. Again, you should not try and add text based on sources you haven't actually read. That's common sense.Volunteer Marek (talk) 12:04, 8 July 2011 (UTC)
 * Please give the WP policy where I must provide the text of a copyrighted study to you. The study is verifiable you; I do not have to provide the not free text to you.Miradre (talk) 12:09, 8 July 2011 (UTC)
 * Also, for this particular study I cite what the abstract says. You do not need to read the body to verify that I cites the abstract correctly. You can read the free abstract and very my text easily.Miradre (talk) 12:24, 8 July 2011 (UTC)
 * Ok, so obviously YOU HAVE NOT read the study, yet you are trying to add text to the article based and referenced on it. You realize that if this was, say, a classroom, and you pulled that kind of a stunt on a paper, that'd earn you a failing grade, right? There's also an implicit dishonesty in this kind of behavior since any reasonable person reading the article would make the rational deduction, upon seeing the cite, that the person who put that text and citation in there, did in fact bother to read what they are including. Hence, this kind of action misleads our readers.
 * Anyway, the text you are trying to add says: Some studies have controlled for economic factors such GDP and still find a significant independent effect of IQ.. Where are these "some studies"? Additionally, without actually looking at the study we don't know how strong the effect is, whether it is statistically significant, how it fits into the broader literature etc. Seriously - if you have not read the study, you have no business putting it into the article.Volunteer Marek (talk) 12:36, 8 July 2011 (UTC)
 * There is no policy preventing citing the abstract. State which policy if you object. The abstract is easily verifiable and I make no further claim than what it says. If you want to add more with sources, please do so.Miradre (talk) 12:38, 8 July 2011 (UTC)
 * I will change "some studies" to something more appropriate.Miradre (talk) 12:40, 8 July 2011 (UTC)

<-- How about not putting it in until you've actually read the study and can provide material for verification from it?Volunteer Marek (talk) 12:41, 8 July 2011 (UTC) And really, cut the Wikilawyering. If you haven't read something, then you shouldn't use it as a source.Volunteer Marek (talk) 12:42, 8 July 2011 (UTC)
 * I have read (at least) what I cite. The abstract. Which is free and easily verifiable unlike the article body. I make no further claims than what the abstract says. What policy exactly prevents me from this? Miradre (talk) 12:49, 8 July 2011 (UTC)
 * Don't be silly. Of course you can't use an academic paper if you have only seen the abstract. Itsmejudith (talk) 13:00, 8 July 2011 (UTC)
 * Which WP policy prevents this? Miradre (talk) 13:01, 8 July 2011 (UTC)

it might be impromptu of me to barge in mid conversation...but if anyone has large objections to the main body of the article,cant they gather supporting research links for the critique,and then log them under the criticism section of the article?its a nice way of presenting two opposing veiws under the overarching context without creating a flame and/or edit war that destabilizes any relevant intelligent debate..i myself think logging critiue under criticism sections especially in this case owuld be good,considering wikipedia has articles on racism and the like...perhaps some tips should be taken from the stylings of that article to help re conform this one to wiki policys? — Preceding unsigned comment added by 71.1.102.196 (talk) 04:59, 17 July 2011 (UTC)

Brain drain and gain
- again, did you actually bother to read the work before inserting it into the text?Volunteer Marek (talk) 14:01, 8 July 2011 (UTC)
 * The material is sourced to peer-reviewed material which I have read.Miradre (talk) 14:11, 8 July 2011 (UTC)
 * Ok, can you provide a passage from the source which illustrates/supports the text you're adding?Volunteer Marek (talk) 14:17, 8 July 2011 (UTC)
 * Paraphrasing which I have done is perfectly acceptable. You can check the source yourself to if it is correct which is more reliable than if I quote some text.Miradre (talk) 14:19, 8 July 2011 (UTC)
 * No, I am asking you to provide a quote from the text which would support the paraphrasing (which is actually no just acceptable but required, in order to avoid copyright violations). It's a request.Volunteer Marek (talk) 14:30, 8 July 2011 (UTC)
 * Would just as much copyright violation here. Do not see why you do not just look up the article? Then you can examine that I do cite selectively or something similar.Miradre (talk) 14:53, 8 July 2011 (UTC)
 * No, if you provide a quote - directly labeled as a quote - here that's not a copyright violation. Inserting text into an article without paraphrasing or indicating it is a quote would be copyvio.
 * I don't need to look up the article, because I'm not the one trying to insert the text into Wikipedia. You want it in, you provide the quote.Volunteer Marek (talk) 16:29, 8 July 2011 (UTC)
 * There is absolutely no requirement for me to provide a quote. I have fulfilled WP:V by giving a verifiable source. However, to humor you I will give a quote: " as it seems, within one generation or even within a few years the impact of dysgenic fertility on IQ means of countries is much smaller than the impact of selective migration."Miradre (talk) 17:00, 8 July 2011 (UTC)

Relation between intelligence and fertility - survival needs to be added
One factor that is missing from this article is discussion of the relationship between intelligence (or IQ) and survival, specifically survival through reproductive age. Most of the studies listed appear to look at the number of children had by those who have survived to reproductive age, and how this relates to intelligence. However if, for instance, there was a strong correlation between intelligence and survival through breeding age, (i.e., those with greater intelligence were more likely to reach the age of having children), then the larger proportion of higher intelligence people of reproductive age could offset the effect of larger number of offspring per individual for those of lower IQ.

Like fish versus people, people have relatively few offspring compared to number of eggs a fish produces, but a larger proportion of human offspring survive to reproduce.

The correlation between IQ and survival is covered in Cognitive epidemiology.

I don't have sources covering this, but it is a link in the logic that needs to be covered for the dysgenic portions of the article to make any sense.

I incorporated these observations in the following edits (Listed here as starting points for discussion/editing, in case they get deleted since they are unsourced.)
 * Added to criticism.
 * Clarified step in logic in lead.

Also, on a related note. So far the claim in the lead that total fertility rate is inversely correlated with IQ is not substantiated by the body of the article, since the summaries of the research given here does not cover total fertility rate. Zodon (talk) 08:02, 11 August 2011 (UTC)

Edit - revised comments above to incorporate Cognitive epidemiology. Zodon (talk) 08:34, 11 August 2011 (UTC)

Citation needed in first paragraph
I wonder if footnote 25 in this article and footnote 9 in this other article cover this one: "Demographic studies have indicated that in humans, fertility and intelligence tend to be inversely correlated, that is to say, the more intelligent, as measured by IQ tests, exhibit a lower total fertility rate" — Preceding unsigned comment added by 186.22.77.196 (talk) 04:43, 24 December 2011 (UTC)

Desired family size and IQ
The claim that "desired family size is apparently the same for women of all IQ levels" needs better sources, and some clarification. It currently has a source just relating to America. It is not clear from the abstract if it refers to the recent sample (during a period of declining fertility), or if it extends back to the earlier study during a period of rising fertility. In either case it may not represent views in other countries (e.g. those with different average IQs). Additional sources would be desirable. Zodon (talk) 20:24, 24 April 2012 (UTC)

Missing coverage of heritability
So far the article hardly mentions heritability, which is an essential part of the dysgenics claims. I added a little bit to the lead, but needs some fleshing out. The whole matter of to what extent IQ is heritable, and the varying extent to which IQ in a population reflects inherited vs. environmental factors is essential to dysgenic/eugenic speculations.

Article may need some reorganization. Should probably have a section specifically on dysgenics that goes through the steps of that argument. The criticism section is really targeted at dysgenic ideas. The observations about correlation between IQ and fertility are just observations. It is particularly when authors start wandering off into dysgenic speculation that this gets dicey. Zodon (talk) 21:03, 24 April 2012 (UTC)

What is with China
Typical western societies have the "Child or carrer" problem. The system is set up, that it's difficult to have both. This while poor people on welfare have enough time to have several childen.

The system of China is complete invers. There are penalties for more than one child. About US$ 5000. Not possible to pay for poor people. Rich people are in common intelligenter and better educated.

So there are more than one child a status symbol. Home employes are common, so also no "Child or carrer" problem.

The consequences, look at the last PISA test, where Shanghai was top. --Pege.founder (talk) 19:21, 10 August 2012 (UTC)


 * I am not disagreeing, but I think you must see a few other points, including


 * China has not 1 child per family, but rather a much larger number, despite being generally less than the average for sub-developed and developing countries, it is still much higher than those you can see in Europe, approaching more that of an economically strong Latin American country, see one-child policy
 * It is not clear if Shanghai and Hong Kong can be extrapolated to the whole country; but I believe that yes it can because
 * East Asian cultures have a reputation of putting enormous value on education, to say, what one of the younger generation do is not his or her business, but the future of the family – seems to be a correct approach for a developing country, I must say, though people shouldn't be all-concerned if this mentality of preparing to the job market since one's earliest active learning age is extremely stressing, leading to the depression and suicide rates one can see among youth in post-industrial East Asia (I know how frustating it is to be extremely pressured to be an overachieving person by your family just to end up being just an average worker and working with what you don't like and asks to much from you, from my own kin, and I don't want it happening again neither with me nor with my probable succession)
 * Their government is also much more concerned and supportive with education than, to say, Brazil, which I bet is going to slow down and lose its potential superpower status if its parasite government does not change all of its policy concerning this issue (I know because I have people who work with education all around me and I am from a state of which education is a perfect long-term problem) – and it won't as States are by definition a problem –, to the point I think it would be rather dumb to the Chinese to have a "liberal democracy" now, if it turns to be something of the like of that bullshit we have. Portuguese people who receive online insults from xenophobic, ignorant, distasteful Brazilians we'll have the final laugh on us during this century
 * So it is a bad argument to say that their differences in relation to contemporary Western society is responsability of good birth control policies. It goes way far beyond it, and is associated with really many cultural traits, specificities and long-term policies. Nevertheless, having liberal laws when it comes to reproductive rights instead of the tight and disastruous laws accross Latin America and Africa responsible for frightening pregnant death stats in clandestine abortions really helps a lot. Lguipontes (talk) 00:33, 30 August 2012 (UTC)

Uncited Statements about Declining Birth Rates
I've deleted the uncited statements in this article blaming declining birth rates on female academic and economic achievement. For starters, these statements were not cited. Also, if we're allowing uncited statements regarding causation there are many other reasons one could come up with for declining birth rates. One reason being industrialization and the fact that children don't participate in the work force as they do in agricultural economies. Another reason would be that child raising work (when it's your own child) is unpaid and therefore less attractive when compared with paying jobs in a market economy. — Preceding unsigned comment added by Shockra998 (talk • contribs) 21:20, 23 December 2012 (UTC)
 * Hi Shockra! The line before you statements that you deleted says: "This well-proven and exhaustively studied group of factors has affected the population policy of all UN member nations" - followed by five sources - and then the statements come. So the statements are actually cited. I've put in a colon for more clarity.  Lova Falk     talk   10:43, 24 December 2012 (UTC)

Some people might misunderstand this article
The article doesn't mention how slowly evolution works, and seems to imply that the problem will eventually worsen. In reality, however, by the time evolution in humans makes any noticeable change many generations would have passed, a time so long genetic engineering would render it obsolete. Not everyone will take that into account, however, and less educated readers might assume that some action might be needed to prevent the problem when nothing, in fact, needs to be done about this. In such a way, this article is kind of misleading. 173.180.202.22 (talk) 23:30, 2 January 2012 (UTC)


 * Honestly, the whole article is pretty goofy.Volunteer Marek (talk) 00:54, 3 January 2012 (UTC)

It's also misleading in that it assumes fertility, the ability to have children, is the same thing as consciously deciding to have less children... Which is proven to be the case in couples with higher IQ's. They tend to think more quality over quantity in light of intellectual labor taking precedence over manual labor, which would require more people than a better quality of people. -Kellie — Preceding unsigned comment added by 98.28.13.133 (talk) 07:33, 23 April 2012 (UTC)


 * In this case fertility is the number of children (as in Total fertility rate), not the ability to have children. If that isn't clear, perhaps should be clarified in the text. Zodon (talk) 20:41, 24 April 2012 (UTC)

The article clearly states, at least per Daniel Vining's hypothesis, that we should expect IQ drop so 1.6 points per decade in the white population, and 2.0 points per decade in the black population. I will not argue the merits of Vining's hypothesis, but the Wiki entry does provide very clear insight to the rate of change we might expect per his hypothesis, for example.

Also, when we speak of "fertility rates", we're not discussing a persons biologic ability to have children. We're speaking of their genetic contribution to the next generation. So, it doesn't matter why they're not reproducing, be it choice or inability. This entry is speaking only to whether or not they pass on their genes to a new generation, and if so, how many copies. If two people have one child, their genetic material's presence in the world is halved when they die, thus removing some of those genes that may independently or collectively correlate with intelligence. If two people chose not to have children at all,that DNA is effectively removed from human existence for any purpose other than lab work. And, that means that the new sum of any particular allele they had in their DNA is N-1, decreasing the probability it gets passed onto the next generation. - TRN450 — Preceding unsigned comment added by Trn450 (talk • contribs) 19:03, 23 January 2013 (UTC)

Removed material
"Robert Klark Graham argued that genocide and class warfare, in particular discussing the examples of the French Revolution and the Russian Revolution, have had a dysgenic effect through the killing of the more intelligent by the less intelligent, and "might well incline humanity toward a more primitive, more brutish level of evolutionary achievement." "

"But Meisenberg (2009) found that both GDP and intelligence independently reduces fertility. Liberal democracy had only a weak and inconsistent effect. Furthermore, "At present rates of fertility and mortality and in the absence of changes within countries, the average IQ of the young world population would decline by 1.34 points per decade and the average per capita income would decline by 0.79% per year."

This has been changed to the misleading "Meisenberg (2009) found that both log of per capita GDP and intelligence were negatively associated with fertility. Liberal democracy had only a weak and inconsistent relationship.".

I propose adding back the lost material.

Acadēmica Orientālis (talk) 14:22, 4 February 2012 (UTC)

I agree with this proposal. We should not be limiting the information we provide to readers. - TRN450 — Preceding unsigned comment added by Trn450 (talk • contribs) 19:06, 23 January 2013 (UTC)

Intelligence citations bibliography for updating this and other articles
You may find it helpful while reading or editing articles to look at a bibliography of Intelligence Citations, posted for the use of all Wikipedians who have occasion to edit articles on human intelligence and related issues. I happen to have circulating access to a huge academic research library at a university with an active research program in these issues (and to another library that is one of the ten largest public library systems in the United States) and have been researching these issues since 1989. You are welcome to use these citations for your own research. You can help other Wikipedians by suggesting new sources through comments on that page. It will be extremely helpful for articles on human intelligence to edit them according to the Wikipedia standards for reliable sources for medicine-related articles, as it is important to get these issues as well verified as possible. -- WeijiBaikeBianji (talk, how I edit) 01:41, 25 June 2013 (UTC) Impressive job WeijiBaikeBianji! Thank you! Lova Falk    talk   08:01, 6 July 2013 (UTC)

Removal of text
Weji removed the following: https://en.wikipedia.org/w/index.php?title=Fertility_and_intelligence&oldid=prev&diff=622879624

Please reinstate. KVDP (talk) 14:03, 26 August 2014 (UTC)


 * Please refer to the reliable secondary sources already cited here on this talk page, in the section posted just before this talk page section. -- WeijiBaikeBianji (talk, how I edit) 15:55, 26 August 2014 (UTC)

Sourcing
Weiji removed a paragraph based on the argument that the source was unreliable due to being a research paper. At present the article is sourced predominantly to such sources, so there is no reason to remove just the one and removing them all would gut the article.-- The Devil's Advocate tlk. cntrb. 17:01, 1 January 2014 (UTC)


 * Every editor can see that I have recommended a large variety of reliable sources in the continually updated  source list on intelligence mentioned in the previous section of this talk page. It would be delightful to see more Wikipedians use sources to improve the  articles on Wikipedia as well as possible to uphold the core Wikipedia policy of  verifiability.


 * The Wikipedia guidelines on reliable sources in medicine provide a helpful framework for evaluating sources. (It should go without saying that an article about fertility and intelligence is inherently an article that makes medical claims.) Those guidelines remind editors that "it is vital that the biomedical information in all types of articles be based on reliable, third-party, published sources and accurately reflect current medical knowledge."

"Ideal sources for such content includes literature reviews or systematic reviews published in reputable medical journals, academic and professional books written by experts in the relevant field and from a respected publisher, and medical guidelines or position statements from nationally or internationally recognised expert bodies."


 * The medical sourcing guidelines, consistent with the general Wikipedia guidelines on reliable sources, remind us that all "Wikipedia articles should be based on reliable, published secondary sources" (emphasis in original). They helpfully define a primary source in medicine as one in which the authors directly participated in the research or documented their personal experiences. By contrast, a secondary source summarizes one or more primary or secondary sources, usually to provide an overview of the current understanding of a medical topic. The general Wikipedia guidelines let us know that "Articles should rely on secondary sources whenever possible. For example, a review article, monograph, or textbook is better than a primary research paper. When relying on primary sources, extreme caution is advised: Wikipedians should never interpret the content of primary sources for themselves."


 * So it's clear enough that if we are to do a good job of improving this article through good sourcing, we should be looking for sources such as "literature reviews or systematic reviews published in reputable medical journals, academic and professional books written by experts in the relevant field and from a respected publisher, and medical guidelines or position statements from nationally or internationally recognised expert bodies," and I am familiar with several of those. I'll recommend some specific sources along those lines for this article, and I invite all other editors here to consider source criteria carefully in deciding how to improve this article. -- WeijiBaikeBianji (talk, how I edit) 18:44, 1 January 2014 (UTC)
 * Here are some citations to articles on the subject recommended to me in November by a medical geneticist and a professional demography researcher who both participate in a "journal club" I also participate in.








 * Both of the review articles point out conceptual errors that are common in studies of fertility and IQ, and the primary research article exemplifies the kind of mediating variables the more careful researchers look for, and the kind of surprising observations one finds when looking at the best ascertained data sets. -- WeijiBaikeBianji (talk, how I edit) 19:46, 1 January 2014 (UTC)


 * This article still needs much improved sourcing. -- WeijiBaikeBianji (talk, how I edit) 15:34, 8 September 2014 (UTC)


 * While I agree that the article should rely on secondary sources more than it does presently and agree that we should use the strongest and most representative sourcing when possible, I have to object to the notion that this article would be covered under WP:MEDRS. No medical claims are made in the article, which is what MEDRS concerns. That such a field has possible implications for medical research is not sufficient to argue for the application of MEDRS. Reputable academic journals focusing on this field are often not medical journals and excluding non-medical journals would be detrimental to a comprehensive treatment of the subject.-- The Devil's Advocate tlk.  cntrb. 19:10, 1 January 2014 (UTC)