Talk:Heritability of IQ

Inbreeding

Charles the III of Spain of the Hapsburgs was an imbecile, and he only had 8 great grand parents. What heading should that go under? 128.206.82.56 (talk) 21:19, 16 June 2009 (UTC)done

Let me state this better. There is clear evidence for inbreeding leading to intellectual deficits. 128.206.82.56 (talk) 16:13, 13 July 2009 (UTC)done

Political discussion

• there is no political diskussion in this artikel
  • Cyril Burt, Raymond Cattell und Charles Spearman are diskussed to have cheating in their publication in order to prove "Inheritance of intelligence" as a fact.
  • 'Inheritance of intelligence' is used to to sanctify an elite among man
  • Stephen Jay Gould says that intelligence as an thing and the Inheritance of intelligence as a whole is an myth. (The Mismeasure of Man) --Nerd

Title change

I suggest changing the title to "Heritability of intellgence" since almost all material is about Heritability. The current title is somewhat POV since it seems to imply genetics. Objections? Ultramarine 02:51, 19 February 2007 (UTC)

Although I second the change in title, I would like to even go further - "intelligence" is a somewhat problematic term, with unscientific connotations, whereas "IQ" has an unambiguous meaning. Thus, "Heritability of IQ" could be even more appropriate as an article title. Harkenbane (talk) 22:58, 8 March 2008 (UTC)

I agree with Harkenbane, go ahead! --Crusio (talk) 10:32, 9 March 2008 (UTC)

As you can see, I've moved the page. But doing so has rendered some passages extraneous; since I'm the one who actually moved the page, I'll try to take responsibility for cleaning the article up over the next few days, but I hope others will try to make necessary changes as well! Harkenbane (talk) 02:26, 10 March 2008 (UTC)

I strongly disagree. "IQ" is simply a number derived from a test of intelligence. It cannot be inherited, and it does not directly correspond to intelligence. Various factors such as education, language and culture affect the correlation between intelligence and IQ. I'd say we rename the article to "Heritability of intelligence." 202.40.139.164 (talk) 11:59, 6 November 2008 (UTC)

I think you're wrong here. "Intelligence" is a concept, as such, it cannot be measured directly. What we measure is an IQ test score, from which we infer the intelligence level. But all that we measure remains the IQ score, nothing more, nothing less. As multiple studies have shown, there is significant heritability for IQ scores. The factors affecting IQ that you describe (education, culture, etc) are environmental factors and because of their presence, the heritability of IQ scores is not 1. --Crusio (talk) 16:31, 6 November 2008 (UTC)

Just one question

Just one;

If intelligence is hereditary, why is it that the overwhelming majority of ultra smart people in the United States do not come from "noble ancestry?"

I mean, most Americans are descended from "European trash," e.g., the working class. To me that doesn't sound like good genetic pedigree regarding the breeding for brains.

Since the majority, the overpowering majority of Europeans who came here were all from "trash" stock, this country should have no smart people at all.

A big, glaring problem with the heredity argument. Indeed, a college professor of mine, whose brother got into that whole ancestry thing, discovered that their great grandfather was a coal miner. From coal miner, to college professor. Its not the only incident either, there are many others. Many people in this country, who teach at Ivy league institutions, who have won nobel prizes, often descend from the lowest of the low from Europe way back when. In Australia, which was originally a prison colony, there are many people there with high I.Q.'s Most of those people are descended from criminals and brigands the British government had deemed "feeble minded."

Of course, I'm not here to make a statement, but to pose a question; if intelligence is inherent, if its inborn, if its genetic, why is it that at one point all of humanity lived in a state of savagery?

Another question I have is, if Europeans according to tests supposedly have higher level II intelligence, I need to ask, why was it that northern Europeans, the ones promoted as being smarter than everyone else, lived in a state of barbarism for hundreds of years?

If intelligence was truly genetic, you'd think they would have created a civilization as sophisticated as that of ancient India or Persia. Were are all the pyramids in Norway? Were are the ancient cities in Germany? Were are the Ankor Wats of England?

No mean to insult anyone here but Stonehenge, when compared to the pyramids in Central America, is hardly an example of brain power.

Is the heredity of intelligence "science" real science, or, is it racist junk science out to abuse its authority to promote racist views?

Nazi Germany abused science in a similar manner; more worrysome though, is the lack of research in how intelligence can be increased. People seem perfectly comfortable in assuming, what you got is what you got, and there is nothing you can do about it.

Sucks for nonwhites, but very convenient for whites. I'm just saying, I hope racist egotism is not the motivating factor for that "science" and "research."

206.63.78.105stardingo747 —Preceding comment was added at 08:23, 8 November 2007 (UTC)

Oh dear, stardingo747.... There is so much to say about this. Intelligence is not genetic. It has a heritable component. Like most complex characters ("complex" here referring to the underlying causes), genes have an influence, so has environment, and often these two interact (meaning that the effects of one depend on the state of the other). Although your above points are well-taken, they do not contradict at all the article as it currently stands. --Crusio 22:40, 9 November 2007 (UTC)

Stardingo. If the people who built Stonehenge were so 'backward', how is it that you're here today speaking in the language of their distant descendants? Runcero (talk) 10:10, 1 November 2009 (UTC)

What now

Too often people work on articles by picking a POV and looking for sources to back it up. I think the way to research an article is to find out what the notable verifiable sources are and then find out what they say (what views they hold) and then come up with an outline for an article that accommodates their views and whatever arguments exist among them. Following this principle I have discovered that there are plenty of good scientific research on the heritability of traits including IQ. A sample of key studies:

• Bouchard, Arvey, Keller, Segal, 1992, Genetic Influences on Job Satisfaction: A Reply to Cropanzano and James,” Journal of Applied Psychology 77(1): 89-93
• Devlin, Daniels, Roeder 1997 “The heritability of IQ” Nature 388: 468-471
• Jacobs, Van Gestel, Derom, Thiery, Vernon, Derom, and Vlietinck, 2001, “Heritability Estimates of Intelligence in Twins: Effect of Chorion Type,” Behavior Genetics 31(2): 209-217
• McCartney, Harris, and Bernieri, 1990, “Growing Up and Growing Apart: A Developmental Metanalysis of Twin Studies” Psychological Bulletin 107(2) 226-237
• Phelps, Davis, Schwartz, 1997, “Nature, Nurture and Twin research Strategies” in Current Directions in Psychological Science 6(6): 117-121
• Plomin and Loehlin, 1989, “Direct and Indirect IQ Heritability Estimates: a Puzzle” Behavior Genetics 19(3): 33-342
• Race, Townswend, Hughes, 285-291, “Chorion Type, Birthweight Discordance, and tooth-Size Variability in Australian Monozygotic Twins” Twin Research and Human Genetics 9(2) 285-291 (no, not about IQ – but as it is about other clear phenotypic traits it provides a good benchmark for assessing the value of twin studies and the various factors one must also take into account)
• Reed, Carmelli, Rosenman, 1991, “Effects of Placentation in Selected Type A Behaviors in Adult males in the national Heart, Lung, and Blood Institute Twin Study,” Behavior Genetics 21(1) 1-19
• Segal, 19999, Entwined Lives: Twins and What They Tell us About Human Behavior
• Sokol, Moore, Rose, Williams, reed, and Christian, 1995, “Intrapair Differences in Personality and Cognitive Ability Among Mynozygotic Twins Distinguished by Chorion Type,” Behavior Genetics 25(5) 456-466
• Stromswold, 2006, “Why Aren’t Identical Twins Linguistically Identical?” Cognition 101(2): 333-383

Now, I have not read most of these, but this is precisely my point: I have not chosen them because they support my POV, but because they are frequently cited by scientists and thus represent notable views, whatever their views are. And this is plenty of material to work through. Slrubenstein | Talk 16:22, 17 December 2007 (UTC)

Actually, I think that most of the key points in the article are already there; most of the revision right now should focus on organizing and formatting the existing material, in my opinion. That stated, I can see a few areas to expand and explore:

• One thing I've been seeing for quite some time now is that there are not likely to be any genes with major effects on IQ, only a great many with minor and minuscule effects that only become important when these effects are aggregated. If anyone knows of any genes with major effects on IQ, that would be important to add.
• Also of interest would be whether heritability remains high outside of developed nations; what is the heritability of IQ in, for example, India?
• Lastly, a brief section on the nature of intelligence may be in order, dealing with g theory and critics who offer alternative models; if intelligence is something besides g, then IQ should not be the focus for the article as it currently is. Harkenbane (talk) 22:54, 8 March 2008 (UTC)

It might be good to also include some comment on the nature of heritability, especially emphasising the fact that heritability is not the same as heredity. We do say that heritability is the relative contribution of genes to variance for a given environment, but maybe we need to emphasise this by specifically saying that it is not a measure of the relative contribution of genes to a trait. It's not at all obvious to the lay person that a contribution to variance is not the same as a contribution to the trait itself. We might also include some small discussion of the validity of hereditary measurements, I know a lot of scientists are sceptical that heritability estimates are at all useful or that they tell us anything worth knowing. There are several papers we can cite for this, in particular David Layzer's paper Heritability Analyses of IQ Scores: Science or Numerology? (it's a bit odd that this very important and directly relevant paper is not cited at all), but also including Commentary: Heritability estimates—long past their sell-by date, The analysis of variance and the social complexities of genetic causation The analysis of variance and the analysis of causes Commentary: Statistical analysis or biological analysis as tools for understanding biological causes, though the emphasis for these latter four deconstructions of heritability should be in the heritability article, which does not seem to contain any critisism of the concept at all. What do you think? Alun (talk) 07:04, 27 March 2008 (UTC)

Overhaul

Discussion brought over from the Race and Intelligence page:

What do people mean when they claim that racial differences cause differences in IQ? According the the lead, it sounds like some people think that race stands for biological differences. In the "Race" section above Alun demonstrates that for biologists race is subspecies and there are no meaningful human races in a biological sense. The question is whether there is a genetic component to differences in IQ scores and this question has nothing to do with "race." Study on the biology of IQ hinges on twin studies. Here is a fair sample of the major sources:

This isn't an article about "race." Harkenbane (talk) 18:39, 26 March 2008 (UTC)

To start us off, I propose we look at these articles:

• Bouchard, Arvey, Keller, Segal, 1992, Genetic Influences on Job Satisfaction: A Reply to Cropanzano and James,” Journal of Applied Psychology 77(1): 89-93
• Devlin, Daniels, Roeder 1997 “The heritability of IQ” Nature 388: 468-471
• Jacobs, Van Gestel, Derom, Thiery, Vernon, Derom, and Vlietinck, 2001, “Heritability Estimates of Intelligence in Twins: Effect of Chorion Type,” Behavior Genetics 31(2): 209-217
• McCartney, Harris, and Bernieri, 1990, “Growing Up and Growing Apart: A Developmental Metanalysis of Twin Studies” Psychological Bulletin 107(2) 226-237
• Phelps, Davis, Schwartz, 1997, “Nature, Nurture and Twin research Strategies” in Current Directions in Psychological Science 6(6): 117-121
• Plomin and Loehlin, 1989, “Direct and Indirect IQ Heritability Estimates: a Puzzle” Behavior Genetics 19(3): 33-342
• Race, Townswend, Hughes, 285-291, “Chorion Type, Birthweight Discordance, and tooth-Size Variability in Australian Monozygotic Twins” Twin Research and Human Genetics 9(2) 285-291 (no, not about IQ – but as it is about other clear phenotypic traits it provides a good benchmark for assessing the value of twin studies and the various factors one must also take into account)
• Reed, Carmelli, Rosenman, 1991, “Effects of Placentation in Selected Type A Behaviors in Adult males in the national Heart, Lung, and Blood Institute Twin Study,” Behavior Genetics 21(1) 1-19
• Segal, 19999, Entwined Lives: Twins and What They Tell us About Human Behavior
• Sokol, Moore, Rose, Williams, reed, and Christian, 1995, “Intrapair Differences in Personality and Cognitive Ability Among Mynozygotic Twins Distinguished by Chorion Type,” Behavior Genetics 25(5) 456-466
• Stromswold, 2006, “Why Aren’t Identical Twins Linguistically Identical?” Cognition 101(2): 333-383

I repeat, the point is not to cherry-pick quotes that we agree or disagree with. The point is to examine reliable sources to find out - yes, find out, as if e may actually learn something new - what the notable views are.

I disagree with the implication that those of us who contribute to this article have not already carried out a literature review - at the very least, that isn't true in my case; I regularly read Intelligence along with other psychological journals. Harkenbane (talk) 18:39, 26 March 2008 (UTC)

From what I gather from this literature, most of the current scholarship - mainstream scholarship - on IQ scores is not even concerned with the debate "is it environmental or is it genetic."

Yes, because the heritability of IQ throughout the developed world has been settled (although the heritability of IQ in developing countries is unknown). Harkenbane (talk) 18:39, 26 March 2008 (UTC)

There is a body of literature, and I provided many citations above, and obviously an article on this research must be organized around the most notable and mainstream views on the matter - it should include all notable views ... but I think that the major notable views should be the principle factor in the organization and presentation of the article.

Virtually all scientific research on the genetic determinants of variation in IQ scores is based on twin studies and above (perhaps now in archived talk) I provided a bibliography of major (i.e. from major peer-reviewed journal journals, and which are frequently cited) articles. These studies indicate an ongoing debate between scientists who measure the heritability of intelligence at .40, and others who measure it at between .60 and .70.

The debate is not ongoing. Research on children shows low heritabilities; on adults, high heritabilities. That the heritability of IQ is below .5 in early childhood and above .7 in late adulthood is commonly accepted throughout the psychological community. Are you aware of any study published in the last 20 years which breaks this trend? Harkenbane (talk) 18:39, 26 March 2008 (UTC)

In addition to these contrasting calculations, there is a debate over the effects of of the shared prenatal environment - some argue that identical blood supply should lead to greater similarities between monochoriatic twins than dichorionic twins; others argue that competition for blood supply should lead to greater differences between monochorionic twins than dichorionic twins. I think we need to have a good article that provides a clear account of this research and these controversies.

You seem to be in a good position to do this; why not simply add it to the present article? Harkenbane (talk) 18:39, 26 March 2008 (UTC)

Perhaps someone who has training in genetics and access to these journals could take the first step in sketching out an article on Heritability and IQ.? Slrubenstein | Talk 20:33, 25 March 2008 (UTC)

Not about intelligence, not about race

This is an article about the heritability of IQ - specifically, the proportion of variance in IQ which is attributable to genetic variance. Consequently, I don't think this is the place to discuss race, intelligence, or race and intelligence. Questions about whether IQ measures "intelligence," whether "race" exists, or whether different populations differ in IQ for genetic reasons, can be addressed elsewhere. Harkenbane (talk) 19:05, 26 March 2008 (UTC)

Harkenbane, my apologies for my confusion about the deletion of comments. To respond to yours, I only wish to reiterate two points. One, I agree with youcompletely that this is not about "race," but the question of heritability of IQ constantly comes up on the Race and Intelligence page. I do not think this article should be rewritten to be about race (unless that is what the notable sources say), I wish only to point out the relevance of this article to another. Two, none of my comments are directed at you personally and I hope you do not take them personally. I have added other sources and topics I think this article should cover; this in no way disparages the work you or others have already done. Slrubenstein | Talk 12:13, 27 March 2008 (UTC)

No need to tread on eggshells. I will say, however, that the relevance of this article to the article on race and intelligence is not large so long as the article sticks to its subject, for the straightforward reason that within group heritability really says nothing about between group heritability. If users on another page are making claims about the within group heritability for IQ which contradict what is written here, I think they should take their concerns to this article - the information given here, while cluttered and poorly presented, is nevertheless that of the mainstream psychological community. If anyone has any information to the contrary of what currently appears, please make the appropriate changes with proper citations! Harkenbane (talk) 17:59, 28 March 2008 (UTC)

I think that's right Harkenbane. The only relevance it has is to do with heritability, in that some researchers claim that because the heritability of IQ is high for some groups then this indicates a string genetic component to the trait, and also that a high heritability for one group must mean a high heritability for all groups. But this is more about these researchers (notably Jensen) conflating heritability with heredity and making false claims about the validity of between group heritability. This article already makes the specific point about within group heritability not being relevant to between group heritability. I do think this article should be more explicit in distinguishing between heredity and heritability. Alun (talk) 18:57, 28 March 2008 (UTC)

Race is an illusion of the flesh, but genetics is not. If an ethnicity is revealed to have a higher genetic predisposition towards learning disabilities by a scientific study, those conducting the study should not be labeled as racist just for their findings. In reality race is but the demographic distribution of genetic traits and it's the problem traits that are the problem, not the race. I personally think it's pathetic that we tend to only classify race by a handfull of cosmetic and superfluous traits that have no impact on personhood other than that our species is weak minded enough to identify with and mimic the behavior of people who look similar to us. IQ is about measured intelligence by the way, the word intelligence is in IQ for a reason. --67.58.85.10 (talk) 17:27, 23 February 2009 (UTC)

Genetics of intelligence

Genetics of intelligence redirects to this article. However I do feel there may be a distinction between the genetics and heritability. Heritability can be measured without the knowledge of the actual genes such as measuring traits over several fruit fly generations. It might be necessary to have a separate article, genetics of intelligence, that focuses only on genes that have been associated with intelligence. Wapondaponda (talk) 23:36, 26 January 2009 (UTC)

Controversial because it's uncomfortable

I hate how legitimate studies are labeled controversial simply because they raise uncomfortable questions or go outside the comfort zones of established mainstream religions. The studies on the genetic factors effecting intelligence are controversial because they raise uncomfortable questions about this "all men born equal" mindset we've been taught to blindly accept.

Face it, everyone isn't born equal, look up birth defects if you don't believe me. Genetics plays a large role in many things, it's still labeled controversial that Genetics effects sexuality even though not a single scientist in the field would deny it, and this is controversial because it brings up bad memories from history class or raises issues relating to ethnicity and demographic areas. We're every bit as subject to genetics and natural selection as the next species and we need to get over our tendency to undermine legitimate scientific case studies just because we don't like what they may reveal to us. Without knowledge we have no power.--67.58.85.10 (talk) 17:21, 23 February 2009 (UTC)

Between-Group Heritability: Revisions & New Article

SUMMARY: Need balanced coverage of section "Between-group heritability", and link to a larger entirely new article on statistic in social science

PROBLEM #1: Coverage of opposing camps in the section titled "Group Comparisons" is not fair/balanced

DETAILS: As of 3:50 pm, US Central Time, Friday, July 3rd, 2009, there are 2 paragraphs in this section. There are a total of 1192 (949+253) characters typed and allowed in favor of one view. Yet there are only 229 characters which have been allowed to represent the opposing view.

The first paragraph is 939 characters (including spaces), which presents the view that between group comparisons of heritability cannot be made for psychometric measures.

The second paragraph is 479 characters (including spaces) and includes 2 sentences. The first sentence is 229 characters, and presents an outdated weak argument supporting the validity of between group comparisons. Rather than proceed to qualifications, expansion, or (better yet) a superior argument from the 'other side', this paragraph then returns to the initial camp, and presents yet another sentence supporting that view, 253 characters long. Strangely, this additional sentence add no value to the argument, save the dropping of another name (it makes no argument, adds no explanatory or evidential information not already presented above).

PROBLEM #2: The debates over statistical significance of group comparisons on psychometric tests is too large to be covered here, and is relevant to many other topics besides intelligence

Yet a third issue, which I attempted to at least mention briefly in this section, is the wide spread deep debates over the significance of statistical comparisons of groups of humans on the basis of psychometric tests. A much large article covering this topic should be created by a QUALIFIED scientist. It should include sections discussing cases of public deception, as well as political motivations. Most importantly though, it should include the actual GENERALLY ACCEPTED standards used in various areas of social and medical research. If lives depend on it, a much higher standard is used for determination of effect size and statistical significance. If it is merely a tool for the elucidation of human nature, for the development of governmental policies, funding, and educational curriculum, or other less "valued" purposes, then the standard is lower. Lastly, this new article should also include some graphical examples depicting important experimental design concepts, such as the masking or confounding of effects, when using only a few descriptive statistical tools. Mostly social researchers are familiar with debates in inferential statistics, but the more fundamental philosophical issues are more esoteric.

Paul.J.Richardson 21:12, 3 July 2009 (UTC) —Preceding unsigned comment added by Paul.j.richardson (talk • contribs)

I think the issue is that Wikipedia requires verified information and rejects original research. Of course there are many strange "facts" in articles that are not properly sourced (and so not verified), but the aim is to verify everything, particularly in articles with a serious scientific basis. The rejection of original research may seem a little harsh, but you will agree if you consider the thousands of POV-pushers and simply ignorant editors that want to include extremely dubious information into a variety of articles. At any rate, the best strategy would be to concentrate on some specific text in the article that you believe should be improved and find some sources to support new text. Johnuniq (talk) 01:25, 4 July 2009 (UTC)

Between-group heritability

This edit changed:

But when one compares the means of the two plots, the variation is entirely environmental, since the between-group genetic differences are not significant.

to:

But when one compares the means of the two plots, the numerical difference between means is mostly environmental, since the within-group genetic differences average out.

I changed "the between-group genetic differences average out" to the second of the above since it looks good to me, but I'm happy with either wording (although sticking to the source would be best). Johnuniq (talk) 01:02, 4 July 2009 (UTC)

An inconsistency

"A 2004 meta-analysis of reports in Current Directions in Psychological Science gave an overall estimate of around three quarters.[8] The New York Times Magazine has also listed about three quarters as a figure held by the majority of studies.[9] This coefficient would imply that r squared is about 0.56, meaning that about 56% of the variance in IQ scores is genetic."

The study under [8] gives no heritability measurement. For doubters, it can be easily accessed from a google search. The measurement for 56% is also considerably lower than the 75% measurement, yet it has no notation. Also, it's rather pointless to quote the NYT article when it gives no citations. —Preceding unsigned comment added by 71.205.11.120 (talk) 17:33, 14 July 2009 (UTC)

Better sources

http://www.news-medical.net/news/2005/04/26/9530.aspx —Preceding unsigned comment added by 76.85.196.138 (talk) 18:04, 15 November 2009 (UTC)

New info from Race and intelligence

I moved a lot of info here from Race and intelligence per a proposal in mediation. Subsequently it has been suggested that information on between-group heritability of IQ should not take up so much space here. I'd like to see how we can best address this issue.

The lead states that this article is primarily about in-group heritability. Why is that? Should between group heritability of IQ not be discussed here at all?

Much of the new info is admittedly about hypotheses to explain the correlation between IQ and race without a mostly hereditarian explanation. I agree that this may not be the best place for this info. Please give ideas for other articles that would be more fitting for this information, while avoiding POV forks (which was my aim in keeping all the information together). T34CH (talk) 20:17, 18 December 2009 (UTC)

Clarification

In regards to the "Inconsistency" piece, that post was incorrect in saying that 56% and .75 were unconnected, considering how 56% definitely is .75 when r-squared. However, the NYT article should be disregarded since it gives genuinely no source. The 2004 paper cited should also have more detail given from it. Are they listing a correlation coefficient or the percentage variance? If possible, papers with public domain access should be listed. There's also no actual reference given on the Posthuma 2002 paper.

On another note, it should also be clarified how much more heritable g is than IQ. —Preceding unsigned comment added by 68.62.1.91 (talk) 21:28, 4 January 2010 (UTC)

Improving the “between-group heritability” section

This section of the article still has some of the same problems that were originally raised during the mediation case for the now-defunct Race and intelligence article, as well as some new problems that resulted from the split. I’d like some attention to be paid to fixing them.

What was a problem previously, and still is one, is that instead of explaining the arguments that are presented in favor of between-group IQ differences being heritable, the “heritability” section devotes a large amount of space to explaining almost nothing. While WP:UNDUE demands that we not devote a larger portion of space to any hypothesis than it receives in the source material, it does not demand that our explanation of a minority viewpoint be uninformative. A new problem is that “heritability” should not be only one subsection of the section “between-group heritability”, because the entire section is discussing between-group heritability. Most of the content of this section was copied verbatim from the Race and intelligence article, in which it was explaining factors which could affect between-group differences in IQ, but if it’s going to be presented as factors which could raise or lower between-group heritability, it’ll need to be reorganized.

I think the best solution to this might be something that DJ proposed during mediation for the Race and intelligence article, which is to take a data-centric approach, focusing on individual lines of data which could affect between-group heritability, rather than on viewpoints about whether it’s heritable or not. Here are some of the specific data points that DJ suggested the article cover:

• the implications of within group heritability for between group heritability
• Spearman's hypothesis and reaction time data
• adoption and early intervention programs
• structural equation modeling of between group differences
• regression equations among siblings
• brain size and other biological correlates
• evolutionary models (see the January (2009) issue of PAID)

This would be in addition to the lines of data which the article discusses already, such as health and quality of education.

I also think that if the scope of this section is limited to discussing factors influencing between-group heritability, several of the points discussed here aren’t relevant, and should be either removed or moved to the Between-group differences in IQ article. For example, the question of test bias that’s raised in the test construction section is relevant to the question of whether IQ can accurately be compared between cultures, but this is a separate question from whether and to what degree between-group differences are heritable.

Before I go about making any of these changes, I’d like to make sure nobody has a significant problem with them. Does anyone have any improvements to suggest about what I’ve proposed here? --Captain Occam (talk) 00:32, 7 January 2010 (UTC)

That all seems reasonable. Be bold! David.Kane (talk) 04:26, 7 January 2010 (UTC)

I’m glad you approve, but I’d prefer to also get an opinion from either DJ or Varoon Arya. I haven’t seen either of them around recently, but I’d like to give them at least a day or so to let me know what they think about the best way to improve this section. --Captain Occam (talk) 12:06, 7 January 2010 (UTC)

POV fork of race and intelligence

I get the impression that this article is slowly becoming a POV fork of the race and intelligence article. It seems that large sections that were part of the race and intelligence have now moved here. I believe the scope of this article is the heritability of intelligence, not supposed differences in intelligence between groups, that is a separate subject. Wapondaponda (talk) 15:32, 7 January 2010 (UTC)

what did you expect? the race and intelligence article should never have been split this way - it's a notable and well-defined topic, even if it was badly named - and so of course the chunks of it are going to morph back into the original article. just a pointless move all around... --Ludwigs2 17:04, 7 January 2010 (UTC)

I’ve just moved most of the content in question from this article to Between-group differences in IQ. I think it makes sense for the Heritability of IQ article to have a few paragraphs discussing between-group heritability, but I agree with the rest of you that most of the information about theories regarding the cause of the IQ difference would be more relevant in that article than in this one. --Captain Occam (talk) 10:01, 8 January 2010 (UTC)

What is intelligence?

After more than 140 years after the creation of the word "eugenics", I must question two things:

1-How many races exists in the world? And Why there's 3,4,5,6,7,8,9,10,10,etc. races in the world?

2-What is intelligence? After read many eugenics tracts, I realized that a person why hight level of IQ/intelligence is someone very bigoted, racist and charlatan. Am I right or wrong and why?

This Israeli site: [Jpost] makes another question: Are Taliban descendants of Israelites?Agre22 (talk) 21:09, 10 January 2010 (UTC)agre22

this page is not here to speculate on that issue, which has not currently been resolved to anyone's satisfaction. this page is only here to discuss the various perspectives that people have had on the question over time. --Ludwigs2 23:02, 10 January 2010 (UTC)

Outright copy and pasting

Some of the paragraphs in the "caveats" section are lifted word for word from the APA statement. There should be more original work in that regard. —Preceding unsigned comment added by Mannoro (talk • contribs) 01:58, 9 February 2010 (UTC)

Education and Intelligence

The birth rate for people with low IQs is MUCH higher than those with high IQs, yet the mean IQ of the world keeps rising and rising. If genes really determined intelligence this would make absolutely no sense. The mean intelligence is increasing because of education. Education = higher IQ, Genes do not = higher IQ. —Preceding unsigned comment added by 68.161.166.90 (talk) 23:24, 7 April 2010 (UTC)

New Paper by Bouchard and His Fellow Researchers Should Be Known to All Editors of This Article

Johnson, Wendy; Turkheimer, Eric; Gottesman, Irving I.; Bouchard Jr., Thomas (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18, 4, 218.

This is a paper I learned about from Johnson, Gottesman, and Bouchard directly, as I happened to be in the "journal club" in their University of Minnesota Department of Psychology during fall semester 2009. It includes the important conclusion, "even highly heritable traits can be strongly manipulated by the environment, so heritability has little if anything to do with controllability," which does a lot to clarify the issues discussed in this article. I take it that everyone who has ever looked at good sources on this topic has heard of Bouchard (and his co-author Turkheimer). Both of these scholars have modified their conclusions in recent years, as they have continued to follow up the data sets they study and to interact with other researchers. —Preceding unsigned comment added by WeijiBaikeBianji (talk • contribs) 11:12, 5 June 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 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) 19:57, 30 June 2010 (UTC)

You are very welcome to suggesting further sources. It's time to update this article based on more current sources, as many of the sources currently cited in this article are obsolete in light of further research. -- WeijiBaikeBianji (talk) 23:22, 4 October 2010 (UTC)

Who has reference number 1 at hand?

I see today a version of this article in which the first statement with a footnote is "Heritability is a measure of the relative contribution of genotype to the variation of a phenotype on a given group in a specific environment." I rather doubt that that is the exact definition of heritability given by any current reliable source (this doesn't appear inside quotation marks in the article), but let's check. What does the cited source actually provide in its own exact words as a definition of "heritability"? How many of you have that source printed out or available online as you edit this article?

-- WeijiBaikeBianji (talk) 13:53, 27 July 2010 (UTC)

Try here: http://ije.oxfordjournals.org/cgi/reprint/35/3/525.pdf pgr94 (talk) 14:26, 27 July 2010 (UTC)

I also have full text access to the cited reference, and will now edit this Wikipedia article accordingly. -- WeijiBaikeBianji (talk) 13:45, 28 July 2010 (UTC)

Considering a merge in of other articles and a title change here.

There has been article talk for a while at some other articles, on the subject of environmental influences on IQ, in which editors have proposed merging those articles with one another or into other Wikipedia articles. This Heritability of IQ article stands out currently as the best sourced, and evidently most watched, of the several articles about various influences on the development of IQ. We can all note for the record that the technical term "heritability [of trait]" of course does not solely mean "genetic influence on [trait]" but rather "estimated balance of environmental and genetic influence on [trait in a particular population]." Thus it might be in the spirit and fact of what this article is really about to retitle it to Environmental and genetic influences on IQ or something like that, with appropriate redirects. This issue is open for your discussion while I read some new sources (copyright 2010) that I have just obtained from academic libraries. Let's discuss what would bring about a yet more current, even more accurate, and clear and educational article on this frequently contentious topic. -- WeijiBaikeBianji (talk) 00:03, 10 August 2010 (UTC)

WP:Article titles should be based on common names for the topic rather than trying to be precisely correct. The google test isn't definitive by any means but 'environmental and genetic influences on IQ" only got 5 hits and taking the quote marks off only brought it to the same level as "Heritability of IQ" quoted literally. "Heritability of intelligence" didn't do as well but was quite respectable. Dmcq (talk) 08:59, 10 August 2010 (UTC)

Dmcq, I was just in a discussion with another editor on a completely unrelated article about article titles, so I can see where you are coming from with your friendly comment. I'll ponder some more which form of restructuring the existing supply of articles will be most helpful to readers and most consistent with established Wikipedia policies and guidelines. -- WeijiBaikeBianji (talk) 16:35, 11 August 2010 (UTC)

A good discussion of this issue by a statistician.

I was browsing around looking for sources for this and other articles, and found an excellent online post, which, although it is not a Wikipedia reliable source, definitely points to a lot of sources that are Wikipedia reliable sources and analyzes those sources with sound judgment. This is a good post to look at while preparing to edit this article. -- WeijiBaikeBianji (talk) 20:37, 11 August 2010 (UTC)

P.S. I expect to edit this article more actively now, as I note that many of the sources are obsolete (there are now much better sources on the same issue), and not all of the sources now in the article follow best practice for sourcing Wikipedia articles. -- WeijiBaikeBianji (talk) 23:24, 4 October 2010 (UTC)

I removed the "regression towards the mean" section

To the extent that such a discussion is warranted here, the correct argument is here. Tijfo098 (talk) 20:45, 14 October 2010 (UTC)

Well, I put it back, but some parts need better explaining and citations. Also a picture like File:Resp-to-sel.jpg would be much more informative, although just for one individual rather than selected population, although that one is still better than a generic regression pic. Tijfo098 (talk) 22:56, 14 October 2010 (UTC)

POV in lead

Rose SP is dissing the entire subfield of quantitative genetics, arguing that it is completely useless nowadays [1]. This is definitely a POV, and should not be used in the lead, especially unattributed. This is not at all how a textbook like Hartl and Clark (which has good reviews [2]) presents the topic. Some nuance is needed. Tijfo098 (talk) 08:55, 15 October 2010 (UTC)

From the book review: "Although the text does not discuss it, the cited paper also showed that there are a large number of genes that are not affected by the environment and/or the background genotype, so phenotypic plasticity is just one of the things that may or may not influence development and survival on the way from genotype to phenotype." A more NPOV presentation is at http://plato.stanford.edu/entries/population-genetics/#StaPopGen Tijfo098 (talk) 09:09, 15 October 2010 (UTC)

Also, Google scholar finds only 3 citations for Rose's 2006 paper. Not exactly a ringing endorsement. Tijfo098 (talk) 09:27, 15 October 2010 (UTC)

Rose is very much committed to a nurture viewpoint. He's been writing this stuff in his books for decades. He had more luck with people paying attention to his arguments against evolutionary psychology than against quantitative genetics, it seems:

• Against biological determinism (1982; only 37 citations)
• Alas, poor Darwin: Arguments against evolutionary psychology (eds. but he wrote the scathing intro, 2000; 260 citations, but you should read the Amazon book reviews [3], especially the one by Dennis Littrell -- can't link directly to it thanks to Wikipedia's idiotic software -- who dissects Rose's style of setting up strawmen—a relevant issue in this wiki article as well.)

Tijfo098 (talk) 09:45, 15 October 2010 (UTC)

However, the general point that a heritability estimate says nothing about malleability (also called mutability or changeability) of a trait is correct science, and is identified in numerous reliable secondary sources as an issue about heritability that is most often misunderstood in public discussions of heritability. The statement is so noncontroversial and mainstream that I can back it up with multiple citations—as I intend to in the planned edit I have already announced here—without any reliance on Rose's publication at all. P.S. I have several textbooks about the subject at hand, including one by Hartl. -- WeijiBaikeBianji (talk) 15:26, 15 October 2010 (UTC)