8 ms·

Most Reported Genetic Associations with Intelligence are Probably False

60 points by tokenadult 13y ago

JoeAltmaier 13y ago
Nature vs nurture is hard to separate, especially when genes and culture tend to be 'handed down' to the same individuals. However I'm curious that they chose to use the very-powerfully-determined-by-genes features of Alzheimers and BodyMassIndex as their control. Surely there are other genetic traits that are not 'disorders' which could have been referenced? Breakdowns in physical function would naturally have larger measurable effects than, say, alcohol metabolism rates or whatever.
- tokenadult 13y ago
  Surely there are other genetic traits that are not 'disorders' which could have been referenced? Studies of the issue of "missing heritability" have often investigated height (bodily stature), which has a very high calculated heritability (resemblance among close relatives) but which must be influenced by hundreds of genes, many of very small effect. Even very extensive genome-wide association studies (GWAS) in large samples find NO gene with large effect on height, and fail to detect most of the presumed associations with height in gene associations investigated in such studies. The review article Johnson, W. (2010). Understanding the Genetics of Intelligence: Can Height Help? Can Corn Oil?. Current Directions in Psychological Science, 19(3), 177-182 http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/Johnson%20Current%20Directions%20Psych%20Science%202010%20(G%20and%20E%20in%20IQ).pdf http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/... looks at some famous genetic experiments to show how little is explained by gene frequencies even in thoroughly studied populations defined by artificial selection.
  - bayesianhorse 13y ago
    One example for the trouble with genetics in intelligence is the issue of Malaria: If a child gets Malaria, it will have a lower intelligence quotient. Resistance/resilience of Malaria sure has genetic factors. Would those factors show up in genetic studies about intelligence? Betcha. Should we accept this variance in IQ as genetic and unavoidable? Or should we just buckle down, eradicate Malaria and stop worrying about these factors?
tcskeptic 13y ago
"These and our other results, together with the failure of whole-genome association studies of g to date, are consistent with general intelligence being a highly polygenic trait on which common genetic variants individually have only small effects." This doesn't seem like a surprising result to me. What is being claimed is not "intelligence is not genetic" but it is that "heritability of intelligence is complex". For something that appears as complicated as human intelligence, wouldn't this be expected?
- scott_s 13y ago
  Things that are "expected" still need to be tested. Also, http://lesswrong.com/lw/im/hindsight_devalues_science/ http://lesswrong.com/lw/im/hindsight_devalues_science/.
Xcelerate 13y ago
Note that the article is not saying that intelligence is not heritable. In fact it makes it quite clear that despite the controversy, the opposite is true: > Although the exact figures have been the topic of much debate, the claim that IQ is at least moderately heritable is widely accepted. IQ may in fact be similar in heritability to the physical trait of height What the article is saying is that intelligence cannot be tied to particular genes: > We sought [and failed] to replicate published associations between 12 specific genetic variants and g using three independent, longitudinal datasets It just goes to show that there isn't necessarily one particular factor you can pick out to predict intelligence; it is a combination of many things. (I shall attempt to avert the impending discussion about the word "intelligence" by clarifying that the sense I am using that word is in the same specific manner that the article is: as an objective measure that is statistically correlated with other measures).
- tokenadult 13y ago
  It may be useful for the discussion here to define what "heritable" means. I like what Eric Turkheimer, a psychologist who investigates the heritability of human intelligence, says about that. "But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how genetic a trait is. That intuition explains why so many thousands of heritability coefficients have been calculated over the years. Once the twin registries have been assembled, it's easy and fun, like having a genoscope you can point at one trait after another to take a reading of how genetic things are. Height? Very genetic. Intelligence? Pretty genetic. Schizophrenia? That looks pretty genetic too. Personality? Yep, that too. . . . "Unfortunately, that fundamental intuition is wrong. Heritability isn't an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed. There are many reasons for making this strong statement, but the most important of them harkens back to the description of heritability as an effect size. An effect size of the R2 family is a standardized estimate of the proportion of the variance in one variable that is reduced when another variable is held constant statistically."[1] [1] Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5 http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Turkheimer%20(2008).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...
btilly 13y ago
This whole field seems likely to be a case study supporting http://xkcd.com/882/ http://xkcd.com/882/. But the research does have a questionable assumption. On p 5 it says, "Such a result would not likely be due to differences in the methods used to generate g in the various datasets under comparison, since g is consistently measured by a wide variety of tests." This is true. However it is also true that, as http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/523.html http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/523.htm... points out, that all evidence we have is consistent with g being a correlation between different ways of weighting a large number of independent factors. If so, then it is easy to have two test measuring g that are fairly well correlated with each other, one of which picks up a particular factor and the other does not. If a gene affects that factor, then the test you use to measure to find these correlations will matter.
- epistasis 13y ago
  > This whole field seems likely to be a case study supporting http://xkcd.com/882/ http://xkcd.com/882/. The scientifically interesting thing is that it's not at all like that XKCD cartoon. Multiple hypothesis testing is built into the design of the studies, and has been from the very start. When it comes to proper interpretation of stats in science, geneticists are at the top of the hierarchy. Your second point is far closer to what I think is going on, but I still think that single-gene studies are the wrong way to go, as you might guess from my username. They're testing for the wrong thing, single locus or single gene causes, of a very complex phenotype with the involvement of many many different loci and genes. So if there are 500-600 genes that are important, maybe one passes the test in your particular subsample, but in a different subsample the rest of the 500-600 genes mediate the effect. I.e. there's not enough complexity in the model to account for the signal. What's worked very well for simple diseases and traits may not work well for complex traits with the influence of many many different genes.
  - btilly 13y ago
    Multiple hypothesis testing is built into the design of the studies, and has been from the very start. When it comes to proper interpretation of stats in science, geneticists are at the top of the hierarchy. It is built into the design of the studies. But studies that do not find results do not get published. Thus there is a lot of room for exceptional results to sneak through despite the attempts to get the stats right.
pron 13y ago
The now famous paper Why Most Published Research Findings Are False (http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020124 http://www.plosmedicine.org/article/info:doi/10.1371/journal...) singles out genetics as a field particularly prone to false positive findings.
tehwalrus 13y ago
I would assume that many behaviours (including language itself) are inherited - and yet have nothing whatever to do with genetics. How would you control for this? Only last week, we had an article on here about how vocabulary in very young children was a function of how much parents talked to their children - with marked differences between economic groups[1]. There are many many systematic errors in this kind of data, and I have no good (ethical) suggestions in how to eliminate them. [1] https://news.ycombinator.com/item?id=6480155 https://news.ycombinator.com/item?id=6480155
- rch 13y ago
  Check out 'The Blank Slate' by Steven Pinker. It presents a fairly thorough accounting of how these sort of conclusions may be reached.
  - tehwalrus 13y ago
    I have that on a shelf somewhere, but I don't think I persevered to the end. I'll have another look, thanks!
- tokenadult 13y ago
  How would you control for this? The classic way to control for cultural and in-family influences in studies of human behavior genetics is to look for the rare cases of monozygotic ("identical") twins brought up in separate households after adoption. Those studies of monozygotic twins reared apart (MZA twins) set a MAXIMUM figure for the heritability of any trait of interest--because the genes are as similar as they can be between two different human individuals, but the environments, even in separate households, may not be as maximally different as they could be in influence on the trait in question. There is a whole book about the most famous study of identical twins reared apart, which took place at my alma mater while I was an undergraduate and postgraduate student there (in other subjects). http://www.hup.harvard.edu/catalog.php?isbn=9780674055469 http://www.hup.harvard.edu/catalog.php?isbn=9780674055469 As some people will remember from the press reports at the time, the most culturally variant upbringing two of the separated twins, Oskar and Jack, studied by the Minnesota researchers received was one twin being raised as a Jew, and the other twin being brought up in Nazi Germany and becoming a member of the Hitler Youth. http://online.wsj.com/article/SB10001424052702303552104577436333754014866.html http://online.wsj.com/article/SB1000142405270230355210457743...
bayesianhorse 13y ago
No surprise there... Knowing a lot about genomic animal breeding made me wonder how people can be so sure about genetic basis of intelligence, while we understand neither intelligence nor the genetic basis behind it. For that matter, even plain body height in humans is barely understood...
no_wave 13y ago
Do we even have a working definition for intelligence at this point that can't have holes poked in it from every direction?
- Guvante 13y ago
  No. A unified definition may be impossible. But not having a concrete definition doesn't make certain inferences impossible.
thetruthhurts 13y ago
"African Americans currently score lower than European Americans on vocabulary, reading, and mathematics tests, as well as on tests that claim to measure scholastic aptitude and intelligence. This gap appears before children enter kindergarten (figure 1-1), and it persists into adulthood. It has narrowed since 1970, but the typical American black still scores below 75 percent of American whites on most standardized tests. On some tests the typical American black scores below more than 85 percent of whites"- http://www.nytimes.com/books/first/j/jencks-gap.html http://www.nytimes.com/books/first/j/jencks-gap.html "Intellectual and personality measures were available from unwed mothers who gave their children up for adoption at birth. The same or similar measures have been obtained from 300 sets of adoptive parents and all of their adopted and natural children in the Texas Adoption Project. The sample characteristics are discussed in detail, and the basic findings for IQ are presented. Initial analyses of the data on IQ suggest moderate heritabilities." - http://www.ncbi.nlm.nih.gov/pubmed/496798 http://www.ncbi.nlm.nih.gov/pubmed/496798 "Adolescents' IQ test scores were similar to those of their parents and siblings only if they were biologically related. Our interpretation of these results is that younger children are more influenced by differences among their family environments than older adolescents, who are freer to seek their own niches." - http://www.ncbi.nlm.nih.gov/pubmed/6872626 http://www.ncbi.nlm.nih.gov/pubmed/6872626 Notice how carefully worded the "interpretation" of that last one was. Rather than suggest that genetics has to do with older adolescence not having IQ scores that match their adoptive parents their "interpretation" is that the adolescences simply chose not to perform as well as their adoptive parents...Anything to avoid controversy. White guilt is getting in the way of a lot of racial/genetic/intelligence/violence studies. People don't want to go back to a time when one group of humans were seen as superior and another inferior. The funny part is, Intelligence wise, whites are NOT superior. Jews are.. Their intelligence levels are higher, achievement levels higher, hackers should know this. Many of Silicon Valleys most prominent companies were started by jews. Facebook, Craigslist, Google. Also a report by Joel Stein from the New York Times showed that every major Hollywood studio was founded by jews. In the fashion world: Ralph Lauren, Levi (Jeans), Guess, Mark Ecco, Men's Warehouse, and most of the brands you see in stores today were also started by jews. "In 1921 Budapest, 88% of the members of the stock exchange and 91% of the currency brokers were Jews, many of them ennobled. In interwar Hungary, more than half and perhaps as much as 90 percent of Hungarian industry was owned or operated by a few closely related Jewish banking families. Jews represented one-fourth of all university students and 43% percent at Budapest Technological University. In 1920, 60 percent of Hungarian doctors, 51 percent of lawyers, 39 percent of all privately employed engineers and chemists, 34 percent of editors and journalists, and 29 percent of musicians identified themselves as Jews by religion. Resentment of this Jewish trend of success was widespread." - Yuri Slezkine. The Jewish Century. Princeton, 2004. ISBN 0-691-11995-3 Since 1921 theres been a lot of catching up by Whites, Blacks, Asians, etc... but Jews are still disproportionately successful and score high.
stonewhite 13y ago
Genes are to humans in the same way CPU instructions are to computers [1]. So this experiment is analogous to measuring the capability /throughput of a computer only by inspecting existence of arbitrary instruction sets. They may be the atomic enabling factors, but can't really say much about something so complex as intelligence. [1]: Richard Dawkins
stonewhite 13y ago
Genes are to humans in the same way CPU instructions are to computers [1]. So this experiment is analogous to measuring the capability /throughput of a computer only by inspecting existence of arbitrary instruction sets. They may be the atomic enabling factors, but can't really say much about something so complex as intelligence. [1]: Richard Dawkins
tocomment 13y ago
Wouldn't intelligence be 100% genetic. I mean humans have intelligence and insects have way less. And all that programming to make one or the other is encoded in the DNA.
- Symmetry 13y ago
  You could just as easily argue that it's 100% environment, since a human who is never provided with food will end up dead, and therefore much less intelligent than an insect.
samatman 13y ago
Heritability is related to the degree to which a trait is genetically determined. The relationship is far from trivial. Skin color makes this much easier to understand. Imagine a couple, where the man and the woman each have one Scandinavian parent and one Bantu parent. Their children could have almost any skin shade. If they have identical twins, those twins will have the same shade of skin. Skin color is genetically determined but the heritability varies. Imagine two people who have the same skin color as our first two, but they come from an island population founded by Norwegians and Nigerians exclusively. They are 20th generation, or 50th. Now, it is likely the skin color of their children will be the same as their own. Intelligence inherits upon many factors. Even identifying those factors proves to be elusive and hard. The good evidence that intelligence is genetic is twin studies: the good evidence that it is variable in heritability is every family you've ever known.
gwern 13y ago
Boring. The effect size of the variants is too small to find with n=10,000, hence any positive findings are almost certainly false positives which will fail to replicate. That's why the 3 SNPs found recently (http://infoproc.blogspot.com/2013/05/first-gwas-hits-for-cognitive-ability.html http://infoproc.blogspot.com/2013/05/first-gwas-hits-for-cog...) were in a sample of n=101,000. There's nothing here to undermine the view that genetics causes much of variation in intelligence, it's just that the variation wasn't as clustered on a few genes as people hoped because it would make the research so much easier.

60 points by tokenadult 13y ago

Nature vs nurture is hard to separate, especially when genes and culture tend to be 'handed down' to the same individuals. However I'm curious that they chose to use the very-powerfully-determined-by-genes features of Alzheimers and BodyMassIndex as their control. Surely there are other genetic traits that are not 'disorders' which could have been referenced? Breakdowns in physical function would naturally have larger measurable effects than, say, alcohol metabolism rates or whatever.

tokenadult 13y ago
Surely there are other genetic traits that are not 'disorders' which could have been referenced? Studies of the issue of "missing heritability" have often investigated height (bodily stature), which has a very high calculated heritability (resemblance among close relatives) but which must be influenced by hundreds of genes, many of very small effect. Even very extensive genome-wide association studies (GWAS) in large samples find NO gene with large effect on height, and fail to detect most of the presumed associations with height in gene associations investigated in such studies. The review article Johnson, W. (2010). Understanding the Genetics of Intelligence: Can Height Help? Can Corn Oil?. Current Directions in Psychological Science, 19(3), 177-182 http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/Johnson%20Current%20Directions%20Psych%20Science%202010%20(G%20and%20E%20in%20IQ).pdf http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/... looks at some famous genetic experiments to show how little is explained by gene frequencies even in thoroughly studied populations defined by artificial selection.
- bayesianhorse 13y ago
  One example for the trouble with genetics in intelligence is the issue of Malaria: If a child gets Malaria, it will have a lower intelligence quotient. Resistance/resilience of Malaria sure has genetic factors. Would those factors show up in genetic studies about intelligence? Betcha. Should we accept this variance in IQ as genetic and unavoidable? Or should we just buckle down, eradicate Malaria and stop worrying about these factors?

tcskeptic 13y ago

"These and our other results, together with the failure of whole-genome association studies of g to date, are consistent with general intelligence being a highly polygenic trait on which common genetic variants individually have only small effects." This doesn't seem like a surprising result to me. What is being claimed is not "intelligence is not genetic" but it is that "heritability of intelligence is complex". For something that appears as complicated as human intelligence, wouldn't this be expected?

scott_s 13y ago
Things that are "expected" still need to be tested. Also, http://lesswrong.com/lw/im/hindsight_devalues_science/ http://lesswrong.com/lw/im/hindsight_devalues_science/.

Xcelerate 13y ago

Note that the article is not saying that intelligence is not heritable. In fact it makes it quite clear that despite the controversy, the opposite is true: > Although the exact figures have been the topic of much debate, the claim that IQ is at least moderately heritable is widely accepted. IQ may in fact be similar in heritability to the physical trait of height What the article is saying is that intelligence cannot be tied to particular genes: > We sought [and failed] to replicate published associations between 12 specific genetic variants and g using three independent, longitudinal datasets It just goes to show that there isn't necessarily one particular factor you can pick out to predict intelligence; it is a combination of many things. (I shall attempt to avert the impending discussion about the word "intelligence" by clarifying that the sense I am using that word is in the same specific manner that the article is: as an objective measure that is statistically correlated with other measures).

tokenadult 13y ago
It may be useful for the discussion here to define what "heritable" means. I like what Eric Turkheimer, a psychologist who investigates the heritability of human intelligence, says about that. "But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how genetic a trait is. That intuition explains why so many thousands of heritability coefficients have been calculated over the years. Once the twin registries have been assembled, it's easy and fun, like having a genoscope you can point at one trait after another to take a reading of how genetic things are. Height? Very genetic. Intelligence? Pretty genetic. Schizophrenia? That looks pretty genetic too. Personality? Yep, that too. . . . "Unfortunately, that fundamental intuition is wrong. Heritability isn't an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed. There are many reasons for making this strong statement, but the most important of them harkens back to the description of heritability as an effect size. An effect size of the R2 family is a standardized estimate of the proportion of the variance in one variable that is reduced when another variable is held constant statistically."[1] [1] Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5 http://people.virginia.edu/~ent3c/papers2/Articles%20for%20Online%20CV/Turkheimer%20(2008).pdf http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...

btilly 13y ago

This whole field seems likely to be a case study supporting http://xkcd.com/882/ http://xkcd.com/882/. But the research does have a questionable assumption. On p 5 it says, "Such a result would not likely be due to differences in the methods used to generate g in the various datasets under comparison, since g is consistently measured by a wide variety of tests." This is true. However it is also true that, as http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/523.html http://vserver1.cscs.lsa.umich.edu/~crshalizi/weblog/523.htm... points out, that all evidence we have is consistent with g being a correlation between different ways of weighting a large number of independent factors. If so, then it is easy to have two test measuring g that are fairly well correlated with each other, one of which picks up a particular factor and the other does not. If a gene affects that factor, then the test you use to measure to find these correlations will matter.

epistasis 13y ago
> This whole field seems likely to be a case study supporting http://xkcd.com/882/ http://xkcd.com/882/. The scientifically interesting thing is that it's not at all like that XKCD cartoon. Multiple hypothesis testing is built into the design of the studies, and has been from the very start. When it comes to proper interpretation of stats in science, geneticists are at the top of the hierarchy. Your second point is far closer to what I think is going on, but I still think that single-gene studies are the wrong way to go, as you might guess from my username. They're testing for the wrong thing, single locus or single gene causes, of a very complex phenotype with the involvement of many many different loci and genes. So if there are 500-600 genes that are important, maybe one passes the test in your particular subsample, but in a different subsample the rest of the 500-600 genes mediate the effect. I.e. there's not enough complexity in the model to account for the signal. What's worked very well for simple diseases and traits may not work well for complex traits with the influence of many many different genes.
- btilly 13y ago
  Multiple hypothesis testing is built into the design of the studies, and has been from the very start. When it comes to proper interpretation of stats in science, geneticists are at the top of the hierarchy. It is built into the design of the studies. But studies that do not find results do not get published. Thus there is a lot of room for exceptional results to sneak through despite the attempts to get the stats right.

pron 13y ago

The now famous paper Why Most Published Research Findings Are False (http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020124 http://www.plosmedicine.org/article/info:doi/10.1371/journal...) singles out genetics as a field particularly prone to false positive findings.

tehwalrus 13y ago

I would assume that many behaviours (including language itself) are inherited - and yet have nothing whatever to do with genetics. How would you control for this? Only last week, we had an article on here about how vocabulary in very young children was a function of how much parents talked to their children - with marked differences between economic groups[1]. There are many many systematic errors in this kind of data, and I have no good (ethical) suggestions in how to eliminate them. [1] https://news.ycombinator.com/item?id=6480155 https://news.ycombinator.com/item?id=6480155

rch 13y ago
Check out 'The Blank Slate' by Steven Pinker. It presents a fairly thorough accounting of how these sort of conclusions may be reached.
- tehwalrus 13y ago
  I have that on a shelf somewhere, but I don't think I persevered to the end. I'll have another look, thanks!
tokenadult 13y ago
How would you control for this? The classic way to control for cultural and in-family influences in studies of human behavior genetics is to look for the rare cases of monozygotic ("identical") twins brought up in separate households after adoption. Those studies of monozygotic twins reared apart (MZA twins) set a MAXIMUM figure for the heritability of any trait of interest--because the genes are as similar as they can be between two different human individuals, but the environments, even in separate households, may not be as maximally different as they could be in influence on the trait in question. There is a whole book about the most famous study of identical twins reared apart, which took place at my alma mater while I was an undergraduate and postgraduate student there (in other subjects). http://www.hup.harvard.edu/catalog.php?isbn=9780674055469 http://www.hup.harvard.edu/catalog.php?isbn=9780674055469 As some people will remember from the press reports at the time, the most culturally variant upbringing two of the separated twins, Oskar and Jack, studied by the Minnesota researchers received was one twin being raised as a Jew, and the other twin being brought up in Nazi Germany and becoming a member of the Hitler Youth. http://online.wsj.com/article/SB10001424052702303552104577436333754014866.html http://online.wsj.com/article/SB1000142405270230355210457743...

bayesianhorse 13y ago

No surprise there... Knowing a lot about genomic animal breeding made me wonder how people can be so sure about genetic basis of intelligence, while we understand neither intelligence nor the genetic basis behind it. For that matter, even plain body height in humans is barely understood...

no_wave 13y ago

Do we even have a working definition for intelligence at this point that can't have holes poked in it from every direction?

Guvante 13y ago
No. A unified definition may be impossible. But not having a concrete definition doesn't make certain inferences impossible.

thetruthhurts 13y ago

"African Americans currently score lower than European Americans on vocabulary, reading, and mathematics tests, as well as on tests that claim to measure scholastic aptitude and intelligence. This gap appears before children enter kindergarten (figure 1-1), and it persists into adulthood. It has narrowed since 1970, but the typical American black still scores below 75 percent of American whites on most standardized tests. On some tests the typical American black scores below more than 85 percent of whites"- http://www.nytimes.com/books/first/j/jencks-gap.html http://www.nytimes.com/books/first/j/jencks-gap.html "Intellectual and personality measures were available from unwed mothers who gave their children up for adoption at birth. The same or similar measures have been obtained from 300 sets of adoptive parents and all of their adopted and natural children in the Texas Adoption Project. The sample characteristics are discussed in detail, and the basic findings for IQ are presented. Initial analyses of the data on IQ suggest moderate heritabilities." - http://www.ncbi.nlm.nih.gov/pubmed/496798 http://www.ncbi.nlm.nih.gov/pubmed/496798 "Adolescents' IQ test scores were similar to those of their parents and siblings only if they were biologically related. Our interpretation of these results is that younger children are more influenced by differences among their family environments than older adolescents, who are freer to seek their own niches." - http://www.ncbi.nlm.nih.gov/pubmed/6872626 http://www.ncbi.nlm.nih.gov/pubmed/6872626 Notice how carefully worded the "interpretation" of that last one was. Rather than suggest that genetics has to do with older adolescence not having IQ scores that match their adoptive parents their "interpretation" is that the adolescences simply chose not to perform as well as their adoptive parents...Anything to avoid controversy. White guilt is getting in the way of a lot of racial/genetic/intelligence/violence studies. People don't want to go back to a time when one group of humans were seen as superior and another inferior. The funny part is, Intelligence wise, whites are NOT superior. Jews are.. Their intelligence levels are higher, achievement levels higher, hackers should know this. Many of Silicon Valleys most prominent companies were started by jews. Facebook, Craigslist, Google. Also a report by Joel Stein from the New York Times showed that every major Hollywood studio was founded by jews. In the fashion world: Ralph Lauren, Levi (Jeans), Guess, Mark Ecco, Men's Warehouse, and most of the brands you see in stores today were also started by jews. "In 1921 Budapest, 88% of the members of the stock exchange and 91% of the currency brokers were Jews, many of them ennobled. In interwar Hungary, more than half and perhaps as much as 90 percent of Hungarian industry was owned or operated by a few closely related Jewish banking families. Jews represented one-fourth of all university students and 43% percent at Budapest Technological University. In 1920, 60 percent of Hungarian doctors, 51 percent of lawyers, 39 percent of all privately employed engineers and chemists, 34 percent of editors and journalists, and 29 percent of musicians identified themselves as Jews by religion. Resentment of this Jewish trend of success was widespread." - Yuri Slezkine. The Jewish Century. Princeton, 2004. ISBN 0-691-11995-3 Since 1921 theres been a lot of catching up by Whites, Blacks, Asians, etc... but Jews are still disproportionately successful and score high.

stonewhite 13y ago

Genes are to humans in the same way CPU instructions are to computers [1]. So this experiment is analogous to measuring the capability /throughput of a computer only by inspecting existence of arbitrary instruction sets. They may be the atomic enabling factors, but can't really say much about something so complex as intelligence. [1]: Richard Dawkins

stonewhite 13y ago

tocomment 13y ago

Wouldn't intelligence be 100% genetic. I mean humans have intelligence and insects have way less. And all that programming to make one or the other is encoded in the DNA.

Symmetry 13y ago
You could just as easily argue that it's 100% environment, since a human who is never provided with food will end up dead, and therefore much less intelligent than an insect.

samatman 13y ago

Heritability is related to the degree to which a trait is genetically determined. The relationship is far from trivial. Skin color makes this much easier to understand. Imagine a couple, where the man and the woman each have one Scandinavian parent and one Bantu parent. Their children could have almost any skin shade. If they have identical twins, those twins will have the same shade of skin. Skin color is genetically determined but the heritability varies. Imagine two people who have the same skin color as our first two, but they come from an island population founded by Norwegians and Nigerians exclusively. They are 20th generation, or 50th. Now, it is likely the skin color of their children will be the same as their own. Intelligence inherits upon many factors. Even identifying those factors proves to be elusive and hard. The good evidence that intelligence is genetic is twin studies: the good evidence that it is variable in heritability is every family you've ever known.

gwern 13y ago

Boring. The effect size of the variants is too small to find with n=10,000, hence any positive findings are almost certainly false positives which will fail to replicate. That's why the 3 SNPs found recently (http://infoproc.blogspot.com/2013/05/first-gwas-hits-for-cognitive-ability.html http://infoproc.blogspot.com/2013/05/first-gwas-hits-for-cog...) were in a sample of n=101,000. There's nothing here to undermine the view that genetics causes much of variation in intelligence, it's just that the variation wasn't as clustered on a few genes as people hoped because it would make the research so much easier.