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Thread: Race and Intelligence

  1. #201  
    Forum Freshman DrNesbit's Avatar
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    Quote Originally Posted by inow
    Quote Originally Posted by Harold14370
    Okay. I noticed a couple of things. (1) They are using IQ (which you discount as a valid test) to validate the accuracy of their brain mapping.
    IQs are mentioned, but so too are their limitations. That's the point. Not only do they talk about the various theories and types of intelligence, but they explicitly refer to other standardized tests such as Spearman’s g. I also quoted a bit about why standardized tests are rather problematic (supporting my and DrmDoc's claim), and why IQ specifically has so many problems. Implicit in your comment is that IQ is the sole measure being used to validate their mapping results, and that is most certainly not the case. Further, even when they do use IQ, that usage is done with a recognition of its inherent limitations and flaws... limitations and flaws which I pointed out very early in this thread.
    Those "problems" with IQ have nothing to do whith how heritable that trait is. If IQ only measures a somewhat narrow "abstract problem-solving ability" and misses some dimensions of what we would call "intelligence", than twin studies etc. can still determine how heritable that specific "aspect of intelligence" is.
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    Quote Originally Posted by DrNesbit
    Quote Originally Posted by inow
    Harold - I made no such contention, but I will say that it's obvious to pretty much everybody that genetics and environment both play a role in this
    Even to DrmDoc? He seems to be saying that genetics play no role at all (or rather, that there's no evidence that genetic plays a role, an argument loosely based upon claiming that "you can't measure intelligence"). See this quote:

    Quote Originally Posted by DrmDoc
    All I am suggesting is that the evidence in brain study does not support the idea or possibility of a genetically expressed intellectual distinction between members of humanity.
    I could certainly be mistaken here, but I assumed that since his comment was made in the context of a discussion about differences in intelligence across the races that he meant there is no distinction across the races. You think perhaps I'm giving him too much credit, or is it possible that everyone else is taking his words out of context?

    I'll go with the second, but of course only DrmDoc can clarify.




    Quote Originally Posted by DrNesbit
    Those "problems" with IQ have nothing to do whith how heritable that trait is. If IQ only measures a somewhat narrow "abstract problem-solving ability" and misses some dimensions of what we would call "intelligence", than twin studies etc. can still determine how heritable that specific "aspect of intelligence" is.
    Agreed. I was responding entirely to Harold's attack on my previous posts to this thread where I suggested that IQ is a rather limited measure of intelligence.
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    Quote Originally Posted by DrNesbit
    Quote Originally Posted by DrNesbit
    Note that in these last few posts I've been defending the idea that intelligence has a significant genetic component, and not saying anything about race (more exactly, I'm saying that a good deal of variation in intelligence between individuals is explained by genetic differences, which seems to be a majority view in the concerned fields).
    If DrmDoc disagrees with that, he certainly hasn't made any effort to clarify his position.
    As your initial evidence of a significant genetic component, you provided a Wiki-link to which I replied with this:

    Quote Originally Posted by DrmDoc
    In the first paragraph of your Wiki-link, I read: "Most of the heritable variance in IQ appears to be carried by the general intelligence factor (or g). IQ is a polygenic trait under normal circumstances according to recent research.[4]" I then select "recent research[4]", and found this article:

    Comings DE, Wu S, Rostamkhani M, et al. (January 2003). "Role of the cholinergic muscarinic 2 receptor (CHRM2) gene in cognition". Mol. Psychiatry 8 (1): 10–1. doi:10.1038/sj.mp.4001095.
    Quote Originally Posted by DrmDoc
    I've reviewed the article you provided. That study involved the twins of Caucasian families and was designed to support an association between CHRM2 gene and cognition. This study used the Wechsler Adult Intelligence Scale-Revised (Vocabulary, Information, Block Design, and Picture Arrangement) test and years of education, by genotype of father and mother, as a basis for its assessments. The study concluded that the CHRM2 gene may account for 1% of the variance in IQ tests and years of education. It suggested that this small percentage may be more meaningful as part of an overall genetic confluence and that this preliminary result requires replication.

    Caucasian families: This was a study of genetic traits among Caucasian families and not between the races. It did not conclude or suggest that the specific genetic trait studied was exclusive to Caucasians. As with alcohol and addiction, certain families among all races could be genetically predisposed to certain traits. However, this does not suggest a baseline racial distinction in intelligence, which is my position

    Wechsler test and years of education: The test administered and education years assessment did not account for the likely variation in the quality of education for the twin family participants or the variations in their socio-economic upbringing and status. These would have been relevant factors in the outcome of test results. Years of education is not the same as instructional quality. What was the variance in education quality and the socio-economic of each participant? The 1% measure of contribution to cognition by CHRM2 suggests that many participants, with this gene expression, did not perform as well. Might this suggests factors beyond genetic?

    1% accountable variance: A 1% possible genetic component is hardly convincing evidence of a “polygenic” trait. The researchers themselves suggested as much in their conclusions with their “in need of replication” comment. Further, their admission of a genetic confluence association with intelligence suggests the effects of other unidentified factors that may be more significant in the expression of intelligence.

    As evidence of the inheritability of intelligence, the reference you provided isn’t a very good one—in my opinion.
    You then offered another Wikipedia reference:

    Quote Originally Posted by DrNesbit
    Quote Originally Posted by Wikipedia
    In 2006, The New York Times Magazine listed about three quarters as a figure held by the majority of studies.[10] A 2004 meta-analysis of reports in Current Directions in Psychological Science gave an estimate of around three quarters as well.[9] As well, a 1996 statement by the American Psychological Association gave about .45 for children and about .75 during and after adolescence.[8] The 2005 edition of Assessing adolescent and adult intelligence by Alan S. Kaufman and Elizabeth O. Lichtenberger found correlations of 0.86 for identical twins raised together compared to 0.76 for those raised apart and 0.47 for siblings.[16] A 1994 review in Behavior Genetics based on identical/fraternal twin studies found that it is as high as 0.92 in general cognitive ability but it also varies based on the trait, with .60 for verbal tests, .50 for spatial and speed-of-processing tests, and only .40 for memory tests.[6]
    To which I replied with this:
    Quote Originally Posted by DrmDoc
    Although I have not seen the Time article, the quote you provided seems to suggest an implied genetic link by way of intelligence testing among twins rather than the direct assessment of a genetic component. The quote suggests a high correlation among twins than among non-twin siblings. The quote also suggests that this correlation persist even when twins are raised separately.

    In my opinion, this is analogous to the notion that twins think and behave alike. For example, twins raised apart, have been known to marry individual by the same [name] or marry individuals who have similar profession. Is there truly a genetic component that causes a twin to make such distinct selections or can we tie these behaviors to a shared period when these twins may have been influenced to make these specific distinctions? Which seems most likely, genetics or a shared period of influence before separation? Did the studies, which this article relies upon, include factors pertaining to gestational influence among twins prior to separation?

    Regarding the variance between twins raised together and their siblings, such correlation could be explained by the distinction of concurrent education at an age apart from other siblings. Often mistook as the same individual, twins share more together than with other siblings. Perhaps this accounts for the similarities between their intelligence as opposed to other siblings.

    I take a critical view of most research because such is invariably influenced by the unconscious ideas and designs of the researcher. Researchers are so convinced of a genetic component to every aspect of humanity that they often fail to consider the most simplistic view. Much of what we are thought to be genetically, may be explained by the in-vitro preparatory influences and processes from human conception to birth.
    And this:
    Quote Originally Posted by DrmDoc
    As I explained previously, studies such as this suggest an implied genetic link that could be explained by other more credible factors. Twins studies conducted in this fashion are not direct or credible genetic evidence of the inheritability of intelligence. If there were such evidence, it could have been suggested by the CHRM2 gene study. As I'm sure you know, this was a direct genetic study and, as I have outlined, it is not sufficient evidence of the inheritability of intelligence nor evidence of a racially distinct intelligence trait.
    After your reply with:

    Quote Originally Posted by DrNesbit
    Direct study of DNA is not necessary to show that something is genetic. For example, you don't need to look at DNA to know that eye color is genetically determined, and careful study can help you determine which genes are recessive and which are dominant, etc. Would you say that there's no direct and credible evidence that eye color is genetically determined until the actual genes involved are listed? Why should things be different for intelligence?
    I replied with:
    Quote Originally Posted by DrmDoc
    Apparent expressions such as eye color are not the same as the expression of an ethereal quality whose attributes are difficult to assess given a general lack of aggreement on how it should be tested. With planets and eye color, we have something tangible to measure and observe with standardize and accepted methods. This is not the same with intelligence. Twin studies without direct genetic components, as I have said, are too easily explained. The only indirect genetic evidence I think less easy to explain would be that suggested by the expression of genius in the progeny of history's great innovators and thinkers (e.g., Newton, Darwin, Einstein, etc.). If intelligence is a heritable trait, as I've asked previously, where is the history of genius in the progeny of history's greats?
    You followed with:
    Quote Originally Posted by DrNesbit
    Yet, still, the opinion of many scientists is that IQ has a significant genetic component. Do you know enough about their research to say with certainty that they haven't considered your "influence during pregnancy" explanation?

    Intelligence is harder to measure than eye color, but that doesn't mean it's entirely imaginative. "Lack of agreement" doesn't mean much - on how many concepts in social sciences is there complete agreement among all researchers? Does that mean all research on the other concepts (on which sometimes people disagree!) is completely invalid?
    To which I replied:
    Quote Originally Posted by DrmDoc
    I disagree; a lack of consensus on how to fairly test intelligence calls into question the validity of any and all research rooted in such testing. Although disagreement, as our discussion observes, is common among us all, there is no disagreement regarding the neurological kinship among the races—which was my original assertion.

    Neurologically, there is no evidence of any variance, genetic or otherwise, in brain development, structure, and function among the races. Therefore, if an intelligence distinction exist, it is likely a result of artificially imposed factors. My assertion was that, given equal advantage and environmental factors, there is no distinction among the races in intelligence potential.
    It is unlikely to some observers, given our discourse, that I have not “made any effort" to clarify my position. It is more likely that my efforts have not met with your satisfaction or idea of what those efforts should have been. We are not automatons designed to follow the script of one person's idea of how we should defend our views.
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    But do you accept that variance in intelligence (in the same race) has a significant genetic component? I got the impression that you didn't, inow got the impression that you did.
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    Quote Originally Posted by DrNesbit
    ...do you accept that variance in intelligence (in the same race) has a significant genetic component? I got the impression that you didn't, inow got the impression that you did.
    There are significant genetic components to brain development and structure, which infers a significant genetic contribution to the brain's cognitive output. However, I remain unconvinced of any race-specific genetic component to intelligence for the reason that it, unlike eye and skin color, is not an overtly heritable or an easily assessable racially distinct trait--in my opinion.
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    Quote Originally Posted by DrmDoc
    Quote Originally Posted by DrNesbit
    ...do you accept that variance in intelligence (in the same race) has a significant genetic component? I got the impression that you didn't, inow got the impression that you did.
    There are significant genetic components to brain development and structure, which infers a significant genetic contribution to the brain's cognitive output. However, I remain unconvinced of any race-specific genetic component to intelligence for the reason that it, unlike eye and skin color, is not an overtly heritable or an easily assessable racially distinct trait--in my opinion.
    Then why do you object to twin studies, and to IQ? Twin studies only support the heritability of IQ, without saying anything about race ...

    Once it's established that there are genes that account for some of the variation of IQ, the discussion of race should only be about how those genes are distributed in different population groups (or more exactly, how the alleles are distributed). Do you agree?
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    Quote Originally Posted by DrNesbit
    Quote Originally Posted by DrmDoc
    There are significant genetic components to brain development and structure, which infers a significant genetic contribution to the brain's cognitive output. However, I remain unconvinced of any race-specific genetic component to intelligence for the reason that it, unlike eye and skin color, is not an overtly heritable or an easily assessable racially distinct trait--in my opinion.
    Then why do you object to twin studies, and to IQ? Twin studies only support the heritability of IQ, without saying anything about race ...
    Because, as I have explained:

    Quote Originally Posted by DrmDoc
    … studies such as this suggest an implied genetic link that could be explained by other more credible factors. Twins studies conducted in this fashion are not direct or credible genetic evidence of the inheritability of intelligence. If there were such evidence, it could have been suggested by the CHRM2 gene study. As I'm sure you know, this was a direct genetic study and, as I have outlined, it is not sufficient evidence of the inheritability of intelligence nor evidence of a racially distinct intelligence trait.
    Once it's established that there are genes that account for some of the variation of IQ, the discussion of race should only be about how those genes are distributed in different population groups (or more exactly, how the alleles are distributed). Do you agree?
    If I may more clearly state, there is no single genetic component to intelligence and science will never find one. The source of our cognitive distinction form other animals is the distinctiveness of our specific brain development, structure, and function. We arrived at this distinction after millions of years of genetic evolution. Our cognitive output involves a confluence of genetic factors associated with human brain development and a concert of unique environmental pressures spurring that development. Science won’t find a specific gene (or sets of genes) because the vast nuances of our central nervous systems (inclusive of brain structure) are formed by many genes.

    From myelencephalon to telecephalon, the genetic foundation of our brain's cognitive output is massive and distinct. It is impossible to breed-out intelligence or breed-in super intelligence among humans without changing the distinctiveness of human brain structure and function. This is shown by the brains of people such as Kim Peeks, an autistic savant. Kim’s brain doesn’t have a corpus callosum (a condition known as agenesis). After an extensive history of slavery and repression (conditions that promote selective breeding) among humanity, the shared distinctiveness of human brain development, structure, and function remains. There remains no evidence of a distinction, genetic or otherwise, suggesting the possibility of a divergence in potential cognitive output (intelligence) among the races. If a divergence exist, it is not caused by any innate or inbred factor.
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    Quote Originally Posted by DrmDoc
    Once it's established that there are genes that account for some of the variation of IQ, the discussion of race should only be about how those genes are distributed in different population groups (or more exactly, how the alleles are distributed). Do you agree?
    If I may more clearly state, there is no single genetic component to intelligence and science will never find one. The source of our cognitive distinction form other animals is the distinctiveness of our specific brain development, structure, and function. We arrived at this distinction after millions of years of genetic evolution. Our cognitive output involves a confluence of genetic factors associated with human brain development and a concert of unique environmental pressures spurring that development. Science won’t find a specific gene (or sets of genes) because the vast nuances of our central nervous systems (inclusive of brain structure) are formed by many genes.
    I'm not sure what difference it makes whether there's one gene or many (which seems more likely). Eye color is controlled by many genes, that doesn't prevent us from reasoning about how the alleles vary in different populations.

    Actually, I'm not really sure whether you're agreeing or disagreeing with the statement "Once it's established that there are genes that account for some of the variation of IQ, the discussion of race should only be about how those genes are distributed in different population groups (or more exactly, how the alleles are distributed).".

    I don't see what the polygenism of mental traits, or selective breeding, or whether certain gene expressions change the brain structure in a visible way have to do with that.
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    Quote Originally Posted by DrNesbit
    I'm not sure what difference it makes whether there's one gene or many (which seems more likely). Eye color is controlled by many genes, that doesn't prevent us from reasoning about how the alleles vary in different populations.
    I'm sure you will agree that the entirety of brain development and structure is dependent on genes. If so, then you should also agree that the entirety of human cognition is dependent on those very same genes--all of them. *[Our brain functions the way it does because of the way it is uniquely structured.]

    I don't see what the polygenism of mental traits, or selective breeding, or whether certain gene expressions change the brain structure in a visible way have to do with that.
    Each area of human brain structure is genetically predisposed to function in a specific order; i.e., the brain is functionally predisposed to engage in activities that create specific neural links. Thought and intelligence requires neural links. These neural links can be seen, functionally tested, and physically examined. If we remove or enhance the genes responsible for this, we will change the visual, functional, and likely physical character of how these neural links form. Thus far, no evidence of this has been found among the races.

    Intelligence isn't solely about the output of cortical function, it is the culmination of cortical and subcortical, afferent and efferent neural processes. Cortical function is built upon the function of preceeding structures. I have postulated that the attributes of mind would not exist without thalmic function (a brainstem structure). If not for the evolution of sight, the thalamus might not have come into existence. We can't [genetically] manipulated the brain's production of intelligence without changing the distinctiveness of those structures and functions associated with producing that quality. The structures associated with intelligence involve every aspects of our central nervous system from myelencephalon to telencephalon.

    *[]=after thoughts.
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  10. #210  
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    Suppose your mother had squished your finely structured brain when you were a baby.

    :-D Sorry, couldn't help it.
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    Quote Originally Posted by Pong
    Suppose your mother had squished your finely structured brain when you were a baby.
    I reiterate, what is your point? A squashed brain is an unnatural occurrence often effected by a narrow vaginal canal. Although this condition may occur frequently, it is not common to all births. Although macrosomia may occur frequently among Hispanics, it is not common to or typical of Hispanics births. If you have a point to make, by all means proceed and let us exit this inane verbal merry-go-round.
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  12. #212  
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    If you've quit insisting that I'm
    Quote Originally Posted by DrmDoc
    designating a single group (Hispanics) as the owner or exhibitor of a specific trait (big babies) to the exclusion of all others.
    then yes. In good faith?

    Honestly I have no agenda or point to win here. I really wanted to explore something, not debate for or against.
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    Quote Originally Posted by Pong
    Honestly I have no agenda or point to win here. I really wanted to explore something, not debate for or against.
    Now, I understand. I had interpreted your comments within the context of this general line of discussion, which involve race-specific intelligence traits. Your intent to enter a separate topic, unrelated to specific genetic or racial traits, was unclear to me. Please, proceed.
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    I think you'll agree "race-specific" by definition is skin colour. This thread would be awfully silly if we're directly linking those genes to intelligence.

    However there's more to "race" than melanin, and I believe what we really mean by race in this thread is characteristic gene sets in populations. In this sense Zulus may share a bunch of genes with Scots, not shared with Balinese, determining bone structure for example. Those aren't "specific genetic or racial traits" that could be called "tall gene" for example, exclusive to a race. However there are certainly some genes effecting tallness or intelligence, not well distributed, and probably some more or less prevalent in different ethnic groups. Of course if you have 71 "height plus" genes and 63 "height minus" you may just end up with longish arms or something. I'm sure there is no single exclusive "intelligence gene".

    I want to explore the implications of ethnically prevalent genes affecting baby development and birth parameters, upon adult intelligence. Childbirth culminates an extremely tight balance of factors, essentially struggling to produce the best brain possible. We know these factors are subject to genetic variation, including variation characteristic to ethnic groups. A collection of factors could be called a strategy. I predict we'll find fetal development and birth strategies differ slightly between ethnic groups, with slightly different child development outcomes, but that ultimately no particular strategy yields an average IQ, or normal intelligence range, more consistently than any other.
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    Quote Originally Posted by DrmDoc
    I'm sure you will agree that the entirety of brain development and structure is dependent on genes. If so, then you should also agree that the entirety of human cognition is dependent on those very same genes--all of them. *[Our brain functions the way it does because of the way it is uniquely structured.]
    This confuses me because I thought you were arguing earlier that brain function depended on environmental factors as well as genetics. The environmental factors were, in fact, what accounted for differences in test scores.

    Do environmental factors affect brain structure? If so, then how could brain structure be the same among races?

    If we remove or enhance the genes responsible for this, we will change the visual, functional, and likely physical character of how these neural links form. Thus far, no evidence of this has been found among the races.
    Has anybody been looking for such evidence? Please elaborate on the studies comparing brain structures of racial groups.
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    Quote Originally Posted by Pong
    there's more to "race" than melanin, and I believe what we really mean by race in this thread is characteristic gene sets in populations. In this sense Zulus may share a bunch of genes with Scots, not shared with Balinese, determining bone structure for example.
    Indeed; but there are no characteristic genes associated with brain development and structure that are known to caused a distinction among the races. When the subject is intelligence, the genes most applicable are those associated with our central nervous system.

    Quote Originally Posted by Harold14370
    …I thought you were arguing earlier that brain function depended on environmental factors as well as genetics. The environmental factors were, in fact, what accounted for differences in test scores.
    If you are confused, I suggest you reread my comments. To paraphrase, I said that there are no genetic differences among the races in brain development, structure, and function. I said that if a racial distinction in our cognitive output exists, that distinction is likely caused by environmental factors. Every element of our physical design requires the expression of genes. Our intelligence weaves its way through a neural design unique to the genetic code of human brain structure. Our brain arises from an expression of specific genes that do not vary, except by mutation, from person-to-person. When there’s no distinction among the genes associated with the brain, what other cause could there be for differences in intelligence among the races?

    Do environmental factors affect brain structure? If so, then how could brain structure be the same among races?
    I have said that artificial factors influence the distinction in intellectual output among the races. Chief among these factors are those associated with environment. A brain not given the advantages of others may not function as well as the others would. Sometimes this condition is permanent; often it is not. In either case, the environmental factors that may influence a brain’s potential do not comprise the genetic code associated with human brain development. There is no repression gene, for example, that could cause the descendent of a slave to submit automatically to the domination or intellect of another. From generation-to-generation, slaves have to be taught submission either by example or by force.

    Has anybody been looking for such evidence? Please elaborate on the studies comparing brain structures of racial groups.
    Yes; I believe Hitler’s scientists (no offense intended) did so extensively. If you are truly interested in that kind of research, may I suggest you look for yourself.
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    Quote Originally Posted by DrmDoc
    Has anybody been looking for such evidence? Please elaborate on the studies comparing brain structures of racial groups.
    Yes; I believe Hitler’s scientists (no offense intended) did so extensively. If you are truly interested in that kind of research, may I suggest you look for yourself.
    Well, I don't think that's quite fair, Doc. When you say that no difference has been found, it implies that someone looked for it, and did not find it, doesn't it. You must have something in mind. What is it?

    Are you really referring to Hitler's experiments? That's not very current research, and probably not very scientific. A Google search for "Hitler racial research" did not turn up anything relevant.
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    Quote Originally Posted by DrmDoc
    Quote Originally Posted by DrNesbit
    I'm not sure what difference it makes whether there's one gene or many (which seems more likely). Eye color is controlled by many genes, that doesn't prevent us from reasoning about how the alleles vary in different populations.
    I'm sure you will agree that the entirety of brain development and structure is dependent on genes. If so, then you should also agree that the entirety of human cognition is dependent on those very same genes--all of them. *[Our brain functions the way it does because of the way it is uniquely structured.]
    Note that what is important is not what is determined by genes, but what variation is explained by genetic variations. To take a common example, the number of eyes of the average human is entirely determined by genes. But most variation of the number of eyes is explained not by genes, but by environmental factors.

    Again, do you agree that variance in intelligence (in the same race) has a significant genetic component?

    Last time I asked that question you answered that "there are significant genetic components to brain developpment", which while true is not really an answer to the question. You seemed to imply "yes" but this whole tangeant on brain structure makes me doubt.

    (note that here I'm not talking about anything race-specific)

    Quote Originally Posted by DrmDoc
    I don't see what the polygenism of mental traits, or selective breeding, or whether certain gene expressions change the brain structure in a visible way have to do with that.
    Each area of human brain structure is genetically predisposed to function in a specific order; i.e., the brain is functionally predisposed to engage in activities that create specific neural links. Thought and intelligence requires neural links. These neural links can be seen, functionally tested, and physically examined. If we remove or enhance the genes responsible for this, we will change the visual, functional, and likely physical character of how these neural links form. Thus far, no evidence of this has been found among the races.

    Intelligence isn't solely about the output of cortical function, it is the culmination of cortical and subcortical, afferent and efferent neural processes. Cortical function is built upon the function of preceeding structures. I have postulated that the attributes of mind would not exist without thalmic function (a brainstem structure). If not for the evolution of sight, the thalamus might not have come into existence. We can't [genetically] manipulated the brain's production of intelligence without changing the distinctiveness of those structures and functions associated with producing that quality. The structures associated with intelligence involve every aspects of our central nervous system from myelencephalon to telencephalon.
    You seem to be saying that every change in intelligence must correspond to a detectable change in brain structure. Are you saying smart people have different brains from stupid people? Or are you saying that because we all have the same brain structure, than we are all of the same intelligence? Either claim seems quite dubious.

    Note that here I'm talking about different individuals (of the same race, to keep things simple), not different races.

    Also, I still don't know whether you're agreeing or disagreeing with the statement "Once it's established that there are genes that account for some of the variation of IQ, the discussion of race should only be about how those genes are distributed in different population groups (or more exactly, how the alleles are distributed).".
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    Quote Originally Posted by DrmDoc
    Indeed; but...
    I think you're still in battle mode, and I don't blame you as it's three on one. I'll pause so you can resolve Harold14370's questions about research, and DrNesbit's regarding significance (badly understating two interesting lines of discussion).
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    Quote Originally Posted by DrNesbit
    Again, do you agree that variance in intelligence (in the same race) has a significant genetic component?
    Variance in intelligence potential. It is the potential where the genetic component is significant.


    Quote Originally Posted by DrNesbit
    You seem to be saying that every change in intelligence must correspond to a detectable change in brain structure.
    It does, in neural connections... which connections are formed, which are pruned, web density, and propagation efficiencies.


    Quote Originally Posted by DrNesbit
    Are you saying smart people have different brains from stupid people?
    They do, but the nature of those differences is still being explored, and it seems rather unlikely that there will be just one or two markers of difference. The differences in "smart" and "stupid" will depend largely on the regions involved with whichever type of intelligence you happen to be measuring... visiospatial, auditory, social, communicative, mathematical, logical, emotional, etc...


    Quote Originally Posted by DrNesbit
    Or are you saying that because we all have the same brain structure, than we are all of the same intelligence? Either claim seems quite dubious.
    Except, we don't all have the same "brain structure." The argument was that there have been no measured differences in average intelligence potential across races, and that the overall neural architecture is so strikingly similar across races that the likelihood of a race based intelligence potential difference is exceedingly unlikely.


    Quote Originally Posted by DrNesbit
    Note that here I'm talking about different individuals (of the same race, to keep things simple), not different races.
    But even identical twins have differences, so I'm confused as to where you're heading with this line of reasoning. There are always individual differences, but the conversation has been one about patterns and average differences across groups... average differences which seem not to exist, nor to be based on any measurable genetic distinctions. Intelligence potential seems consistent across racial groups, and studies repeatedly demonstrate that the environment has the strongest impact on realization of genetic potential... regardless of skin color or eye color or anything else.
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    Quote Originally Posted by DrNesbit
    You seem to be saying that every change in intelligence must correspond to a detectable change in brain structure. Are you saying smart people have different brains from stupid people? Or are you saying that because we all have the same brain structure, than we are all of the same intelligence? Either claim seems quite dubious.
    If I may further clarify, the type and number of potential neural connections within the brain determine intelligence potential. Environmental factors affect our intelligence potential by influencing the potential neural connections the brain makes, while genetics determine the brain's response to environment, the character or form of its neural connection, and the pattern or structure of the brain’s connections.

    Beginning with the overall pattern or structure of the brain and its development (a genetics determinant), visual, olfactory, tactile, auditory, taste, and sensorimotor information is perceived and processed by aspects and areas of the brain that do not diverge among the races. How sensory information is process—how the brain converts sensory information into neural connections (a genetic determinant)—is not racially divergent. The speed at which the brain neurally perceives and responds to sensory information (a genetic determinant) is racially uniform if not affected by environmental or genetic factors.

    A recently reported study suggests that the autistic brain receives sound information a fraction of a second slower than that of a normal brain. In an article written several years ago by an articulate autism sufferer, I read that he didn’t look directly into the faces of others who spoke to him because he could not processing visual and sound information at the same time. The lag time in the autistic brain’s perception of sound sensory suggests a functional disorder inconsistent with what is normal to all brains. Kim Peeks agenesis could be evidence of how environmental influences adversely affect normal genetic expression. Genetics provide a foundation that remains consistent from race-to-race, birth-to-birth, unless affected by artificial factors that cause mutations (e.g., agenesis).

    Finally, the type and number of potential neural connections within the brain determine intelligence potential. The environment influences the potential connections the brain constructs by way of privation and advantage. Privation can take the form of environmental contaminants that cause mutation, inadequate nutrition, sensory experience deprivation, or unequal education. Advantage could take the opposite. Clearly, a brain starved or deprived of what it requires to form neural connections and reach its full potential will not produce the cognitive results of one that is not starved or deprived. As environments tend to evolve, the expression of intelligence potential evolves. However, the genetics remain consistent unless caused to mutate and, as I have written continually, no evidence of such a distinction in brain development, structure, and function among the races exist.

    Quote Originally Posted by Harold
    Well, I don't think that's quite fair, Doc. When you say that no difference has been found, it implies that someone looked for it, and did not find it, doesn't it. You must have something in mind. What is it?
    http://www.jneurosci.org/cgi/content/full/28/47/12176

    http://www.jneurosci.org/cgi/content/full/24/38/8223

    http://www.millersville.edu/~bduncan...cles/giedd.pdf

    http://cercor.oxfordjournals.org/cgi...ull/15/12/1848

    Next time, try a Google Scholar search for brain study. You will find, as I have, numerous racially mixed comparative studies involving several aspects of brain development and structure, from infancy to old age.
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    Quote Originally Posted by DrmDoc
    http://www.jneurosci.org/cgi/content/full/28/47/12176

    http://www.jneurosci.org/cgi/content/full/24/38/8223

    http://www.millersville.edu/~bduncan...cles/giedd.pdf

    http://cercor.oxfordjournals.org/cgi...ull/15/12/1848

    Next time, try a Google Scholar search for brain study. You will find, as I have, numerous racially mixed comparative studies involving several aspects of brain development and structure, from infancy to old age.
    Racially mixed, yes. Comparing ethnic groups to one another, no.
    This is from the second link above:
    The children in the original sample were recruited by word of mouth and from presentations to parent groups at elementary schools. Children were excluded if they had neurological or psychiatric diagnoses, were in remedial classes, or had been tested for gifted enrollment.
    That doesn't seem like the sample you would choose if you wanted to compare ethnic groups to one another.
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    Is there a relation to race among child prodigies? When I google this topic I can only find lists of whites and asians, unless I specifically try black child prodigies, and then I come up with a site which lists young african-americans. I know of the great sporting icons, but I am thinking in terms of mental ability.
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    Quote Originally Posted by inow
    Quote Originally Posted by DrNesbit
    Again, do you agree that variance in intelligence (in the same race) has a significant genetic component?
    Variance in intelligence potential. It is the potential where the genetic component is significant.
    If you want. If something has an effect on "potential intelligence", it will have an effect on actual IQ. IQ has the advantage of being something you can actually measure in a pretty unambiguous way. The important point is that what needs to be explained is not the actual trait, but the variance of that trait in a population.


    Quote Originally Posted by inow
    The argument was that there have been no measured differences in average intelligence potential across races, and that the overall neural architecture is so strikingly similar across races that the likelihood of a race based intelligence potential difference is exceedingly unlikely.
    How exactly was intelligence potential measured?

    This exact argument can be made about people: would you agree that "There have been no measured differences in intelligence potential between people"? Or "The overall neural architecture is so strikingly similar that the likelihood of an intelligence potential difference is exceedingly unlikely."?

    Quote Originally Posted by inow
    Quote Originally Posted by DrNesbit
    Note that here I'm talking about different individuals (of the same race, to keep things simple), not different races.
    But even identical twins have differences, so I'm confused as to where you're heading with this line of reasoning. There are always individual differences, but the conversation has been one about patterns and average differences across groups... average differences which seem not to exist, nor to be based on any measurable genetic distinctions. Intelligence potential seems consistent across racial groups, and studies repeatedly demonstrate that the environment has the strongest impact on realization of genetic potential... regardless of skin color or eye color or anything else.
    DrmDoc seems to be saying that "similar brains" is evidence of "similar intelligence". But that argument doesn't even hold for people, why would it hold for races?

    To me it seems like a non-sequitur or a straw man (has anyone here been arguing that different races have different inherent brain architecture?). Sticking to differences between individuals makes things simpler.

    Fixed your quote for you - KALSTER
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    Quote Originally Posted by DrmDoc
    Quote Originally Posted by DrNesbit
    You seem to be saying that every change in intelligence must correspond to a detectable change in brain structure. Are you saying smart people have different brains from stupid people? Or are you saying that because we all have the same brain structure, than we are all of the same intelligence? Either claim seems quite dubious.
    If I may further clarify, the type and number of potential neural connections within the brain determine intelligence potential. Environmental factors affect our intelligence potential by influencing the potential neural connections the brain makes, while genetics determine the brain's response to environment, the character or form of its neural connection, and the pattern or structure of the brain’s connections.

    Beginning with the overall pattern or structure of the brain and its development (a genetics determinant), visual, olfactory, tactile, auditory, taste, and sensorimotor information is perceived and processed by aspects and areas of the brain that do not diverge among the races. How sensory information is process—how the brain converts sensory information into neural connections (a genetic determinant)—is not racially divergent. The speed at which the brain neurally perceives and responds to sensory information (a genetic determinant) is racially uniform if not affected by environmental or genetic factors.

    A recently reported study suggests that the autistic brain receives sound information a fraction of a second slower than that of a normal brain. In an article written several years ago by an articulate autism sufferer, I read that he didn’t look directly into the faces of others who spoke to him because he could not processing visual and sound information at the same time. The lag time in the autistic brain’s perception of sound sensory suggests a functional disorder inconsistent with what is normal to all brains. Kim Peeks agenesis could be evidence of how environmental influences adversely affect normal genetic expression. Genetics provide a foundation that remains consistent from race-to-race, birth-to-birth, unless affected by artificial factors that cause mutations (e.g., agenesis).

    Finally, the type and number of potential neural connections within the brain determine intelligence potential. The environment influences the potential connections the brain constructs by way of privation and advantage. Privation can take the form of environmental contaminants that cause mutation, inadequate nutrition, sensory experience deprivation, or unequal education. Advantage could take the opposite. Clearly, a brain starved or deprived of what it requires to form neural connections and reach its full potential will not produce the cognitive results of one that is not starved or deprived. As environments tend to evolve, the expression of intelligence potential evolves. However, the genetics remain consistent unless caused to mutate and, as I have written continually, no evidence of such a distinction in brain development, structure, and function among the races exist.
    Again, here I'm not talking about differences between races, but between individuals - mostly because I don't think your arguments hold when talking about individuals (more exactly, it seems that your argument allows us to say that there is no difference in "intelligence potential" between individuals).
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    Quote Originally Posted by Harold14370
    This is from the second link above:
    The children in the original sample were recruited by word of mouth and from presentations to parent groups at elementary schools. Children were excluded if they had neurological or psychiatric diagnoses, were in remedial classes, or had been tested for gifted enrollment.
    That doesn't seem like the sample you would choose if you wanted to compare ethnic groups to one another.
    I don't know why you are questioning that sample, as their efforts were rather obviously intended to eliminate as many confounding variables as possible.
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    Quote Originally Posted by DrNesbit
    The important point is that what needs to be explained is not the actual trait, but the variance of that trait in a population.
    Indeed. Here's the essence of my stance. There are differences in intelligence potential across people. Those differences are not race specific, but individual specific. Trends of difference have not been found between races. Given a roughly equal potential in the population, environmental factors become the strongest predictor of differences in aptitude testing. This is supported by my earlier link which elucidated this topic quite robustly.



    Quote Originally Posted by DrNesbit
    This exact argument can be made about people: would you agree that "There have been no measured differences in intelligence potential between people"?
    No. A simple review of the neural architecture of a mentally handicapped child and a normally functioning child will inform conclusions regarding their significant differences in potential. Where I think we're getting unnecessarily tied around the wheel here is in the fact that I recognize inherent variance within the population of neuro-typicals (what I'm considering "normal"), but I accept the mean of that group as roughly representative of the overall population. To be clear, I am NOT arguing that there are no individual differences.


    Quote Originally Posted by DrNesbit
    Or "The overall neural architecture is so strikingly similar that the likelihood of an intelligence potential difference is exceedingly unlikely."?
    If I've understood you correctly, then... Yes. I would agree with that comment.



    Quote Originally Posted by DrNesbit
    DrmDoc seems to be saying that "similar brains" is evidence of "similar intelligence".
    Again... Similar intelligence potential.


    Quote Originally Posted by DrNesbit
    Sticking to differences between individuals makes things simpler.
    Sure, but we can still discuss trends and tendencies, and rebut claims that there are differences and distinctions when, in fact, there really are not.
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    Quote Originally Posted by inow
    Quote Originally Posted by Harold14370
    This is from the second link above:
    The children in the original sample were recruited by word of mouth and from presentations to parent groups at elementary schools. Children were excluded if they had neurological or psychiatric diagnoses, were in remedial classes, or had been tested for gifted enrollment.
    That doesn't seem like the sample you would choose if you wanted to compare ethnic groups to one another.
    I don't know why you are questioning that sample, as their efforts were rather obviously intended to eliminate as many confounding variables as possible.
    The point is, the purpose of that study was obviously not to compare any intelligence related traits of one ethnic group versus another. If you were studying that, you would not throw out subjects above or below some intelligence thresholds. That would tend to equalize your sample, when what you were looking for is a difference. Nor do I think you would recruit your sample by some word of mouth process if you wanted a representative sample of a population.
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    Quote Originally Posted by Harold14370
    Quote Originally Posted by iNow
    I don't know why you are questioning that sample, as their efforts were rather obviously intended to eliminate as many confounding variables as possible.
    The point is, the purpose of that study was obviously not to compare any intelligence related traits of one ethnic group versus another.
    I agree. I should have thought more clearly about your intended point prior to responding.

    Quote Originally Posted by Harold14370
    If you were studying that, you would not throw out subjects above or below some intelligence thresholds. That would tend to equalize your sample, when what you were looking for is a difference. Nor do I think you would recruit your sample by some word of mouth process if you wanted a representative sample of a population.
    Just so we're clear, though, their population selection method was fine based on the nature of the study conducted. From the link:

    We applied computer-matching algorithms and new techniques for measuring cortical thickness (in millimeters) to the structural MRI images of 45 children scanned twice (2 yr apart) between the ages 5 and 11. Changes in brain size were also assessed

    <...>

    In the present report, we have estimated longitudinal changes in cortical thickness in millimeters during childhood
    You're free to ask DrmDoc why he used that study in support of his point, or how it applies, but the point I am making here is that their selection method was perfectly appropriate based on what they were studying.
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    Quote Originally Posted by Harold14370
    Racially mixed, yes. Comparing ethnic groups to one another, no.
    From the first study:

    Although our sample size is not ideal for examining subsets of children, we did limited analyses on the effects of gender and ethnicity. Mean TBV was larger in males than females at all ages (95% CI: 2–8%; 3–13%, and –1 to 8% for neonate, age 1, and age 2, respectively). This difference is slightly lower that that observed for ICV in neonates, 9% (Gilmore et al., 2007b ), and adults, 11.9–14.6% (Gur et al., 1999 ; Raz et al., 2004 ). Growth patterns across all regions and substructures appeared highly similar between the genders, with the interesting exception of ventricular volume which dropped 1% between age 1 and age 2 in girls but dropped 24% in boys in the same period. This result must be treated with caution given the small sample size and high variability in ventricular volume. Results for all analyses were similar when we examined only those children who were white.
    Here, a neural comparison between a group of Caucasian children and those in this racially mix study were found to yeild similar results. The second article was significant for its lack of stated findings regarding a racial distinction. However, subsequently links from this second article led to this article:

    http://www.jneurosci.org/cgi/content...urcetype=HWCIT

    Association between FA values and ethnicity/race
    An additional regression analysis was performed to determine whether controlling for participants' ethnicity (Hispanic: yes, no) and race (Caucasian: yes, no) affected the observed association between 5-HTTLPR and left frontal FA values. [Because of the small numbers of people of non-Caucasian race, we combined them into a single race category. A chi-square test showed that there were no differences in the distribution of allele frequencies across our non-Caucasian groups ( 2(8,15) = 3.82, p = 0.87).] A regression model that included race, ethnicity, and 5-HTTLPR genotype as predictors of FA values of the left hemisphere frontal region of the UF was significant, F(1,36) = 4.88, p < 0.01, R2 = 0.31. Importantly, the 5-HTTLPR genotype effect remained significant (b, –152.18; SE, 61.11; β, –0.38; t = –2.49; p < 0.05), whereas the effects for race (b, 159.58; SE, 94.08; β, –0.27; t = 1.70; p = 0.099) and ethnicity (b, –58.09; SE, 117.13; β, –0.08; t = –0.50; p = 0.623) were not significant.
    And this article:

    http://www.jneurosci.org/cgi/content...urcetype=HWCIT

    The analysis of functional magnetic resonance imaging (fMRI) data focused on the variations in both local and interregional patterns of brain activity as a function of resistance to peer influence (RPI). RPI was assessed with a self-report questionnaire for adolescents designed to minimize socially desirable responding (Steinberg and Monahan, 2007 ). This instrument has been used in a number of large sample studies. Scores stay low during early adolescence and increase linearly from 14 years of age to reach adult levels at 18 years of age; this pattern is consistent across ethnic groups, reflecting the reliability and generalization of the measure (Steinberg and Monahan, 2007 ).
    If you'll recall, your inquiry regarded the equivalency of racial neural function in brain study. It was my hope that you would take the time to peruse the studies I provided for yourself and find the relevant passages or links to the insight you seek. In most of this type of research, racial comparisons are implied by the racially mixed study-participant sampling. If the study is thorough, significant racial distinctions will be reported. However, more often than not, such distinction are minor and seldom reported as such. If you are truly interested in finding evidence of some neural distinction among the races, you will take the time to do the relevant document research. Try a search at this site and follow the reference links in the subsequent documents you find interesting:

    http://www.jneurosci.org/search.dtl

    Quote Originally Posted by DrNesbit
    Again, here I'm not talking about differences between races, but between individuals - mostly because I don't think your arguments hold when talking about individuals (more exactly, it seems that your argument allows us to say that there is no difference in "intelligence potential" between individuals).
    Indeed, that is my argument; if given equal advantage, from gestation through adulthood, barring genetic mutation, I believe we are all individually capable of the same intellectual potential. I think the primary argument here is nature (genetics) versus nurture (environment). Although we all share the same neural genetics that produce brain structure, it is environment that primarily shapes the potential intelligence brain structure produces.
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    Quote Originally Posted by DrmDoc
    Although we all share the same neural genetics that produce brain structure, it is environment that primarily shapes the potential intelligence brain structure produces.
    Here's where our agreement on the topic parts company a bit. As my example above about mentally handicapped versus neuro-typicals demonstrated, there are differences in both neural genetics and brain structure which are important to consider... we most certainly do not share the same neural genetics and structures (but there is, of course, a mean structure and genetic set across the population). My sense, however, is that you were just not being precise with your language with that comment? (because, I agree that... given a roughly equal intelligence potential and neural architecture, the environment is the single strongest factor in shaping and realizing intelligence).
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    He said "environment ... primarily" so besides mutation the remainder must be inherited variation.
    A pong by any other name is still a pong. -williampinn
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    Thanks, Pong. I think that you're probably correct.
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    Quote Originally Posted by inow
    Here's where our agreement on the topic parts company a bit. As my example above about mentally handicapped versus neuro-typicals demonstrated, there are differences in both neural genetics and brain structure which are important to consider... we most certainly do not share the same neural genetics and structures (but there is, of course, a mean structure and genetic set across the population). My sense, however, is that you were just not being precise with your language with that comment? (because, I agree that... given a roughly equal intelligence potential and neural architecture, the environment is the single strongest factor in shaping and realizing intelligence).
    My position is that we share the same neural genetics in structure, meaning how our brain is constructed and how that construction is influenced by environment. Across all racial distinctions, we are able to locate the same cognitive and functional centers of the brain in the same areas of brain architecture. Barring genetic mutation or abnormal function (likely caused by evironmental factors), our brain receives afferent stimuli, constructs mind and consciousness, and responds to stimuli in a neural fashion that is racially uniform. Inherited variances infer qualities outside what is genetically normal to human brain structure and function. Mental illness suggests a functional abnormality--outside that expressed through the common genetic heritage of human brain development--that could be caused by genetic inconsistencies, injury or other indeterminate environmental factors. When we find variances in intellectual potential, indeed we should look at genetics. Although we know that environment affects genetic expression, we have not found sufficient evidence of a genetic persistency of those affects from generation-to-generation without the associated environmental pressures. Here, I am referring to environmental pressures that do not cause gene mutation.

    The high occurrence of mental illness among families with a history of this malady suggest the involvement of a strong genetic component. This further suggests a mutation or divergence from the genetic heritage of humanity in the history of these families. Effectively, this could be evidence of how small genetic variations significantly influence cognitive function. However, again, we have found no race-specific evidence of such variations that could account for variations in intelligence. Therefore, we must again consider environmental pressures as the likely source of such variations.
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    Quote Originally Posted by DrmDoc
    Indeed, that is my argument; if given equal advantage, from gestation through adulthood, barring genetic mutation, I believe we are all individually capable of the same intellectual potential.
    ... and that's where I disagree, which is why I didn't want to get race mixed up in this too, since if we disagree about the cause of variance within a population, of course we'll disagree about the cause of variance between populations!

    I'm mostly following what I see as the majority opinion in the fields of psychometrics and population genetics: there have been several studies trying to assess the respective influence of genes and the environment on IQ; twins raised apart in different environments end up with similar adult IQs; the adult IQs of adoptive siblings (raised together, but not related) are uncorrelated, unlike the adult IQs of "blood" siblings. All those point towards a significant genetic impact on IQ. So no, it seems that the data doesn't support an equal intellectual potential for everyone.

    You seem to be saying that the fact that all (neurotypical) brains are similar supports your idea - but if you observed no variance in brains, how can you prove the observed brain attributes predict intelligence ? (Or "Potential intelligence" if you prefer, though I've yet to hear someone explain how that is measured) Isn't that a bit like saying that since everyone has two legs, everyone has the same "running potential"? (You could even point to a few pathological cases of people missing a leg or two to bolster the idea that "number of legs" predicts "running ability")
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    Or to present things differently, you're talking about the causal chain

    genes -> brain -> potential intelligence

    ... and saying that since the brains are the same, the potential intelligence is the same.

    I'm saying that this link :

    genes -> IQ

    ... can itself be examined by twin studies etc. - and most evidence so far does point towards such a link. What the intermediate steps are and whether they are directly observable in the brain is another issue - one that doesn't give us much information on the strength of the genes -> IQ link.
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    If I understand correctly, you believe that genes point to IQ and that twin studies are the strongest evidence of such. You have also suggested that my idea of a baseline genetic potential is untestable. I believe you know my position regarding the validity of twin studies. Regarding the testability of my idea, we would not have standards by which to judge structural and functional anomalies in the brain without comparative studies suggesting some baseline quality among individuals. If there is a baseline standard to brain structure and function, then variances in cognitive output between individuals from that baseline suggest anomalies that could be genetic but are most likely environmentally rooted.

    There are genetic variances, some racial, regarding body type and appearence. However, variances in intelligence is not clear evidence of genetically based brain (lobe positioning, function, and formation) variations between individuals. Why do we pursue the complex when the simplest view is often there in front of our noses? The simplest and most likely cause (Occam’s razor) of IQ variances is suggested by how we nurture that quality. I'm sure you are aware of studies suggesting the strong effect of nurture over cognitive development. Give an expectant mother quality nutrition, a stable environment, and enriching experiences (mentally and emotionally) throughout her pregnancy and she will deliver a remarkably balanced and intelligent baby. Give that baby equal advantage and comfort through to adulthood and he or she will excel intellectually--in my opinion.
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    Quote Originally Posted by DrmDoc
    If I understand correctly, you believe that genes point to IQ and that twin studies are the strongest evidence of such. [...] I believe you know my position regarding the validity of twin studies.
    Yes, you believe you have an alternative explanation (shared uterus) and that makes it OK to ignore the genetic implications of all twin studies. As far as I know, that is not a position held by anybody in behavioural genetics, psychometrics, etc.

    Ignoring the results of a field of study doesn't seem like a good way to reach true beliefs about the world; unless you have very good evidence on you side, and a reason for why the researchers would have ignored that evidence.

    Quote Originally Posted by DrmDoc
    You have also suggested that my idea of a baseline genetic potential is untestable. [...] Regarding the testability of my idea, we would not have standards by which to judge structural and functional anomalies in the brain without comparative studies suggesting some baseline quality among individuals. If there is a baseline standard to brain structure and function, then variances in cognitive output between individuals from that baseline suggest anomalies that could be genetic but are most likely environmentally rooted.
    I'm not sure of what this means - is there or is there not a way to measure "intellectual potential"?
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    By the way, DrmDoc, how do you explain this data? (from Wikipedia:Twin Study)



    The height of each column is the correlation for the concerned trait between twins; in black, identical twins; in white, fraternal twins. How do you explain that identical twins are more correlated on those traits than fraternal twins are? They were raised in the same environment, from conception on ... the only difference is that identical twins share all their genes, and fraternal only half (on average). If the environment was all that mattered, shouldn't the correlation be the same whether the twins are identical or fraternal?
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    Quote Originally Posted by DrNesbit
    Yes, you believe you have an alternative explanation (shared uterus) and that makes it OK to ignore the genetic implications of all twin studies. As far as I know, that is not a position held by anybody in behavioural genetics, psychometrics, etc.
    If you will recall, I gave this article as evidence of the possibility of non-genetic gestational effects, which could be passed from a mother's experience to the fetus where it may manifest as future behavior.

    http://www.sciencedaily.com/releases...0512093301.htm

    Ignoring the results of a field of study doesn't seem like a good way to reach true beliefs about the world; unless you have very good evidence on you side, and a reason for why the researchers would have ignored that evidence.
    Did these field studies rule-out the possibility of in-vitro effects and were these studies specifically designed to support a genetic link to the exclusion of much simpler environmental factors? Did you ask yourself these questions before accepting their results?

    I'm not sure of what this means - is there or is there not a way to measure "intellectual potential"?
    Isn't intellectual potential a product of brain function? Aren't there established medical and procedural standards for measuring normal brain function? If a brain varies from such standard, is it normal? Isn't this evidence of some baseline distinction applicable to all?

    We seem to be experiencing a cycle of point/conterpoint with no end in sight. I believe my position cannot be stated any clearer than I have done. I've cited articles, provided references, and gave examples as you have, yet we both remain entrenched in our own perspective. As I believe you have said, let us just agree to disagree and move on.
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  41. #241  
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    Quote Originally Posted by DrNesbit
    since everyone has two legs, everyone has the same "running potential"?
    I sensed that argument also. Sometimes DrmDoc you give the impression brains are clockworks, which is pretty good smokescreen to laypeople like myself.


    Quote Originally Posted by DrmDoc
    we would not have standards by which to judge structural and functional anomalies in the brain without comparative studies suggesting some baseline quality among individuals
    Actually we now have MRI and a growing baseline for even fetuses. We're looking at the brains of healthy newborns and finding a surprising amount of hemorrhaging even in small babies. In time we'll be able to quantify what is "normal" damage given a head diameter and birth canal.


    Quote Originally Posted by DrNesbit to DrmDoc
    you believe you have an alternative explanation (shared uterus) and that makes it OK to ignore the genetic implications of all twin studies.
    I think genetics could matter even where a woman carries babies fertilized in vitro, by egg donor. More on that later.
    A pong by any other name is still a pong. -williampinn
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  42. #242  
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    I think, if we throw free choice into the equation, we'll attain an alternative perspective of intelligence. To clarify, we may consider many cognitive functions as occurring autonomously but if we implicate free choice, we create a diverse response; the presence of free choice may therefore have manifested through evolution to propagate manual development. Given this consideration, intelligence will therefore balance on memory (given that it retains succeeded developments derived from a manual process and distributes them as autonomic processes) - the baseline for all other cognitive operations - and chance, thereby conceiving balanced potential (i.e. we all have an equal intelligence potential). Ultimately, this disseminates the currency of intelligence (i.e. pattern recognition and response, and other cognitive functions constructed upon memory as their foundation would be nothing other than a coincidental development transpired through evolution ergo to manual development; thus, what may arise as a coincide in the future may value discretely as greater intelligence), and may further denote it as nothing other than a mere value ascribed by the ego system.
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  43. #243  
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    Well, it seems like intelligence can't be quantified via non-arbitrary means. Does this mean science cannot test intelligence? If so, that would put intelligence in the same category as the supernatural, which I think many would not like.
    Intelligence is fundamental to science, and independent thought.
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  44. #244  
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    Science can define and test and measure intelligence just fine. The challenge is that there are many different types and layers of intelligence, so more than one test is required. No need to invoke ridiculous notions of supernatural.
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  45. #245  
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    Perhaps our definition of intelligence is more complex than it needs to be.

    Proposal, for sake of discussion: Intelligence, in urban adults, is the ability to understand the operation and purpose of a flush toilet. So sub-imbeciles lack full intelligence. Everybody else is intelligent.

    Then we find if genes can cause a lack of intelligence, and if those genes are more common in some ethic groups.
    A pong by any other name is still a pong. -williampinn
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  46. #246  
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    Quote Originally Posted by DrmDoc
    Quote Originally Posted by DrNesbit
    Yes, you believe you have an alternative explanation (shared uterus) and that makes it OK to ignore the genetic implications of all twin studies. As far as I know, that is not a position held by anybody in behavioural genetics, psychometrics, etc.
    If you will recall, I gave this article as evidence of the possibility of non-genetic gestational effects, which could be passed from a mother's experience to the fetus where it may manifest as future behavior.

    http://www.sciencedaily.com/releases...0512093301.htm
    I'm not saying that there can be no gestational effect, I'm saying that it isn't good enough a reason to dismiss all twin studies.

    Quote Originally Posted by DrmDoc
    Ignoring the results of a field of study doesn't seem like a good way to reach true beliefs about the world; unless you have very good evidence on you side, and a reason for why the researchers would have ignored that evidence.
    Did these field studies rule-out the possibility of in-vitro effects and were these studies specifically designed to support a genetic link to the exclusion of much simpler environmental factors? Did you ask yourself these questions before accepting their results?
    Do you apply that kind of skepticism to all fields of study? I consider researcher (and those who review their papers) as more qualified in their domain than I am, I generally don't go around looking for alternative explanations because 1) that's usually a good way to shoot oneself in the foot, and 2) I trust the social process of science to come up with much better counter-arguments than I can, especially against politically uncorrect ideas.

    Accepting what looks like the consensus among those who study something until better evidence comes along is a pretty good heuristic, that you probably use too on less politically charged subjects.

    Quote Originally Posted by DrmDoc
    I'm not sure of what this means - is there or is there not a way to measure "intellectual potential"?
    Isn't intellectual potential a product of brain function? Aren't there established medical and procedural standards for measuring normal brain function? If a brain varies from such standard, is it normal? Isn't this evidence of some baseline distinction applicable to all?
    You still haven't really answered my question. Are you saying that your measure of "intellectual potential" is "take a look at the brain, check for any obvious missing bits or deformities or anomalies in functioning like epilepsy, and there you have your intellectual potential."? If so, you could state so directly.

    Quote Originally Posted by DrmDoc
    We seem to be experiencing a cycle of point/conterpoint with no end in sight. I believe my position cannot be stated any clearer than I have done. I've cited articles, provided references, and gave examples as you have, yet we both remain entrenched in our own perspective. As I believe you have said, let us just agree to disagree and move on.
    Is that a way of saying that you don't have an explanation for the higher IQ correlations for "true" twins than for fraternal twins?

    (Edit: whoops, screwed up quote formatting again)
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  47. #247  
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    Quote Originally Posted by inow
    Science can define and test and measure intelligence just fine. The challenge is that there are many different types and layers of intelligence, so more than one test is required. No need to invoke ridiculous notions of supernatural.
    Depends on what your goal is - measure intelligence, or measure heritability of mental traits. If you're just studying heritability of mental traits, as long as the trait is well defined and can be measured reliably, you can try to find how heritable it is.

    As for the various types of intelligence, it can be interesting to know whether they vary together or not (like height and shoe size do) or independently (like weight and eye color do - as far as I know). It seems that they mostly vary together, which is part of the justification for a "general intelligence factor" that accounts for most of the variance (tough not necessary saying much about the underlying causality - it could still be a bunch of different factors).

    I don't know if there were any studies about which of the various aspects of intelligence are more or less heritable (there probably were).
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  48. #248  
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    DrmDoc you've repeatedly stressed that gestation and birth - conditions you agree seriously affect brain development - are environmental not genetic. I disagree. I'm arguing that genes often have cross-generational implications. For examples a (genetically) schizophrenic mother will probably give her fetus poor nutrition, an alcoholic mother will of course inflict fetal alcohol syndrome, an addictive mother may birth a crack baby. These are real demographics we're working to correct. Our explicit goal is to raise smarter children from these legacies. Perplexing the issue isn't helpful.

    Can you agree a mother's genes affect a child's intelligence?
    A pong by any other name is still a pong. -williampinn
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  49. #249  
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    Quote Originally Posted by DrNesbit
    As far as I know, that is not a position held by anybody in behavioural genetics, psychometrics, etc.
    Quote Originally Posted by DrmDoc
    If you will recall, I gave this article as evidence of the possibility of non-genetic gestational effects, which could be passed from a mother's experience to the fetus where it may manifest as future behavior.

    http://www.sciencedaily.com/releases...0512093301.htm
    I'm not saying that there can be no gestational effect, I'm saying that it isn't good enough a reason to dismiss all twin studies.
    I’m not saying that there can be no genetic effects, I’m saying that there could be simpler, more credible reasons.

    Ignoring the results of a field of study doesn't seem like a good way to reach true beliefs about the world; unless you have very good evidence on you side, and a reason for why the researchers would have ignored that evidence.
    Quote Originally Posted by DrmDoc
    Did these field studies rule-out the possibility of in-vitro effects and were these studies specifically designed to support a genetic link to the exclusion of much simpler environmental factors? Did you ask yourself these questions before accepting their results?
    Do you apply that kind of skepticism to all fields of study?
    Yes! Except I don’t call it skepticism, I call it critical analysis. Critical analysis doesn’t necessarily invalidate a study’s results, it merely uncovers significant questions whose answers could be crucial to what those results truly suggest.

    I consider researcher (and those who review their papers) as more qualified in their domain than I am,…
    Are you saying that your review of any established research doesn’t involve a critical eye? Are the researchers or, for that matter, is anyone truly more qualified to render your objective opinion on a subject though you may not hold credentials in same? Lack of objectivity (researcher bias) is a chasm between hypothesis and truth, which only opposing and alternative perspectives may breach. It hardly seems likely that you would trust your opinion to another when you are fully capable of understanding and analyzing the available data for yourself. As I have said, “we are not automatons…”.

    …I generally don't go around looking for alternative explanations because…
    Are you saying that you accept what you are told blindly and don’t question authority? How does one support a perspective without question? This sounds more like faith than reason.

    …1) that's usually a good way to shoot oneself in the foot, and 2) I trust the social process of science to come up with much better counter-arguments than I can, especially against politically uncorrect ideas.
    1)Indeed, something like this happened to Galileo when his myopic peers rejected his progressive arguments about the nature of the universe. Nevertheless, Galileo was right.
    2)Indeed, and the social process is called critical analysis.

    Accepting what looks like the consensus among those who study something until better evidence comes along is a pretty good heuristic, that you probably use too on less politically charged subjects.
    I’ve literally read thousands of papers and currently assist others with their dissertations and doctorial candidacy. I’ve worked with doctors for most of my professional life and have come to realize that many of them are not the sharpest pencils in the box. Consensus is fine, if one enjoys the comfort and security of the pack (or mob if one prefers). However, I find that the person who trusts his own judgment and shouts “The Emperor is naked” often speaks the greatest truth.

    I'm not sure of what this means - is there or is there not a way to measure "intellectual potential"?
    Quote Originally Posted by DrmDoc
    Isn't intellectual potential a product of brain function? Aren't there established medical and procedural standards for measuring normal brain function? If a brain varies from such standard, is it normal? Isn't this evidence of some baseline distinction applicable to all?
    You still haven't really answered my question. Are you saying that your measure of "intellectual potential" is "take a look at the brain, check for any obvious missing bits or deformities or anomalies in functioning like epilepsy, and there you have your intellectual potential."? If so, you could state so directly.
    You seem to be asking questions for which we already have answers. Although influenced by environment, intellect is a product of brain function. Correct?

    If you agree that brain function produces our intellect, then you agree that any abnormality of brain function could affect that intellect.

    I presumed that you were familiar with current technologies (fMRI, CT Scans, EEG, etc) by which we are able to assess critical aspects of brain function. These technologies measure brain function as a diagnostic tool to distinguish between normal and abnormal function and structure. The presumption of these technologies is that human brain function and structure has a normal or standard. This normal or standard suggest a functional and structural equivalency between individuals. When these technologies yield brain test results outside this functional and structural equivalency, those results suggest abnormality in the brain.

    Your question was, “is there or is there not a way to measure intellectual potential?” Well, the answer is yes. We begin with a study of brain function because brain function produces our intellect. We look for functional efficiencies and deficiencies as a way of measuring potential output. Since intelligence is a potential output of brain function, then any efficiencies or deficiencies we find may significantly influence that potential.

    …you don't have an explanation for the higher IQ correlations for "true" twins than for fraternal twins?
    The distinction in IQ correlates between identical and fraternal twins could be explained by the nurture effect. Identical twins share the same appearance and are more often perceived as the same individual than are fraternal twins. I believe there is an expectation among some caregivers that identical twins would be the same in every way, which is often not the case. However, identical twins, because of their similar appearance, are nurtured more alike than fraternal twins who are clearly different in appearance. Here, the differences in appearance result in differing treatment by caregivers, which results in intelligence distinctions.

    Quote Originally Posted by Pong
    Can you agree a mother's genes affect a child's intelligence?
    Indeed a fetus first environment is its mother's womb and, as I have argued, that is where nurturing of intellect begins. Although a mother's genetic abnormality may have an affect on fetal development, that abnormality may not necessarily manifest genetically in future generations; i.e., the fetus may not inherit the mother's genetic abnormality. This raises the potential for normalcy in future generations.
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  50. #250  
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    Conducting statistics on the competency of each racial type, i guess u can have a good idea of which racial type is much more intelligent.
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  51. #251  
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    An old friend on mine when still little more than a child made the most astute remark ever on the topic or race and intelligence. he was explaining why he harbored no racist attitudes toward the so-called 'blacks' and would deign to hate no one. (He himself was considered to be 'white' although he was more of a pinkish, flesh tone, blotchy reddish hue.)

    All that needs to be said:


    "There are just as many stupid white people as there are stupid black people."
    And what does the Lord require of you but to love justice, to be merciful and to walk humbly with Him?
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  52. #252  
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    This may be interesting to bring up. I found this.

    misconceptions about evolution | The Antisocial Darwinist

    This unfortunately is not my field of expertise so, what does everyone here make of it?
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