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The possibility of Ashkenazi Jews being more intelligent than average people

  1. Jun 8, 2005 #1
    Today I read an article in The Economist outlining the studies of Gregory Cochran (which will be published in the upcoming edition of the Journal of Biosocial Science), in which he posulates that Ashkenazi Jews are more intelligent than the average person because of natural selection. He also believes that many of the hereditary diseases that are suffered (disproportionately) by Ashkenazi Jews are related to their above average intelligence.

    The case linking diseases to intelligence is a bit weaker than the case in general for the particular selection in favor of particularly intelligent Jews.

    "In the Middle Ages, European Jews were subjected to legal discrimination, one effect of which was to drive them into money-related professions such as banking and tax farming which were often disdained by, or forbidden to, Christians. This, along with the low level of intermarriage with their gentile neighbours (which modern genetic analysis confirms was the case), is Dr Cochran's starting point.

    He argues that the professions occupied by European Jews were all ones that put a premium on intelligence. Of course, it is hard to prove that this intelligence premium existed in the Middle Ages, but it is certainly true that it exists in the modern versions of those occupations. Several studies have shown that intelligence, as measured by IQ tests, is highly correlated with income in jobs such as banking.

    What can, however, be shown from the historical records is that European Jews at the top of their professions in the Middle Ages raised more children to adulthood than those at the bottom. Of course, that was true of successful gentiles as well. But in the Middle Ages, success in Christian society tended to be violently aristocratic (warfare and land), rather than peacefully meritocratic (banking and trade).

    Put these two things together—a correlation of intelligence and success, and a correlation of success and fecundity—and you have circumstances that favour the spread of genes that enhance intelligence. The questions are, do such genes exist, and what are they if they do? Dr Cochran thinks they do exist, and that they are exactly the genes that cause the inherited diseases which afflict Ashkenazi society.

    West Africans, and people of West African descent, are susceptible to a disease called sickle-cell anaemia that is virtually unknown elsewhere. The anaemia develops in those whose red blood cells contain a particular type of haemoglobin, the protein that carries oxygen. But the disease occurs only in those who have two copies of the gene for the disease-causing haemoglobin (one copy from each parent). Those who have only one copy have no symptoms...

    Dr Cochran argues that something similar happened to the Ashkenazim...

    The sphingolipid-storage diseases, Tay-Sachs, Gaucher's and Niemann-Pick, all involve extra growth and branching of the protuberances that connect nerve cells together. Too much of this (as caused in those with double copies) is clearly pathological. But it may be that those with single copies experience a more limited, but still enhanced, protuberance growth. That would yield better linkage between brain cells, and might thus lead to increased intelligence. Indeed, in the case of Gaucher's disease, the only one of the three in which people routinely live to adulthood, there is evidence that those with full symptoms are more intelligent than the average. An Israeli clinic devoted to treating people with Gaucher's has vastly more engineers, scientists, accountants and lawyers on its books than would be expected by chance.
    "

    - http://www.economist.com/science/displaystory.cfm?story_id=4032638

    So hows about that?
     
  2. jcsd
  3. Jun 8, 2005 #2
    that doesn't sound very politically correct at all...imagine if the same claims were made about people of Germanic decent? wow, watch the flames fly..
     
  4. Jun 8, 2005 #3
    Who cares if it's politically correct? What should matter is if it's scientifically correct.

    If someone could present evidence that Germanic people are statistically better than average at something, who would have a problem with it?

    People having the fear of differentiating between different groups of people has gotten ridiculous lately. I've recently been told that the genetic differences between an Italian and an Indian are as negligable as the differences between two Italians, and that there was no more or less difference between any two people in the world genetically. This is plainly BS, as specific populations of any species are more closely related than populations which naturally live in totally different environments thousands of miles away, but because of this PC BS, people are too scared to even admit that everyone is not exactly within the standard deviation of the mean.
     
    Last edited: Jun 8, 2005
  5. Jun 8, 2005 #4

    selfAdjoint

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    Here is a link to the paper: http://harpend.dsl.xmission.com/Documents/AshkenaziIQ.jbiosocsci.pdf

    Reading it you see they lay out plenty of evidence that
    - The Ashkenazi IQ and g dirstributions are shifted up relative to European averages
    -That non-Ashkenazi Jewish distributions are not
    -and that Jews of classical times were not noticed to be especially smarter than other peoples.

    They conclude that Ashkenazi enhanced intelligence is real and has been an adaptive evolutionary development of the last 80 or so generations (roughly since +800). This is only a prologue to their main thesis about the relationship of "Ashkenazi" diseases like Tay-Sachs to enhanced brain wiring, and hence greater intelligence. This has been called the "overclocking" hypothesis, by comparison to the practice of tweaking computer cpus to make them faster at the cost of being more fragile.
     
  6. Jun 9, 2005 #5

    Monique

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  7. Jun 9, 2005 #6

    i don't disagree that science should continue to pursue truth, without regard to politics or who's feelings get hurt.

    but ask yourself: what if a similar study was done to show that a particular race was dumber than others? do you think it would get funded? i don't. do you think the authors would get railroaded? i do. i also think that because we are talking about jews it is "OK", but if it were some other group there would be an uproar. So the same standard is not applied equally, and so science continues to suffer from racial politics, regardless.
     
  8. Jun 9, 2005 #7

    Monique

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    I just read the cartoon guide to genetics (Gonick & Wheelis 1983) and there is a cartoon in there that is very striking, but true. It says: The generals have been known to turn new technology to military use, and they usually find scientists to oblige...

    Then you see a general sitting on the back of a scientist with a contract hanging from a fishing rod, holding it in front of the crawling scientist. The general says: "Repeat after me: "It's just pure research!"", the scientist replies "It's...pure...". (I wish I had a scanner)

    I still think it is the nature of scientist to find correlations, here they want to use a special population to show the correlation of a genetic defect to intelligence. How often have scientist shown the correlation of genetic defects to disease in special populations.. is there something wrong with this too?

    Just because the Finns have some peculiar genetic diseases, does not mean that the Finns are peculiar. I see it the same way with the Ashkenazi.
     
  9. Jun 9, 2005 #8

    Ouabache

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  10. Jun 9, 2005 #9
    Peculiarity of a latent or of a discrete kind

    There is peculiarity in terms of latent factors and peculiarity in terms of dicrete factors. If Finns are especially prone to some particular disease, that implies that they are indeed peculiar — at least in that latent respect.
     
  11. Jun 9, 2005 #10

    loseyourname

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    From the other thread:

    One of the oddities of human evolution is how quickly humans evolved their intelligence. The increase in brain size from our chimp-like ancestors to primitive man to modern man happened far faster than almost any other known evolutionary event. Given the extreme plasticity of the brain and the Baldwin effect that results from this, it would seem to me that intelligence is one trait that should actually be able to change rather rapidly in a given population.
     
  12. Jun 10, 2005 #11

    Monique

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    The thesis is that the genetic diseases that occur at higher frequency in the Ashkenazi population cause them (the carriers) to be more intelligent, the same way that carriers of the sickle cell mutation are resistant to the malaria parasite. I don't know whether these genes have an effect, that is what needs to be found out and will give us new insight in the workings of the brain.
    Every population is peculiar in its own right. The Finns lack some genetic diseases that are common in other populations, but they display some rare recessive disorders. You win some you lose some.
     
  13. Jun 10, 2005 #12
    It takes longer than the time from the middle ages until now for an evolutionary directed process to occur such as increased intelligence. (Quantification of intelligence is also controversial.)
     
  14. Jun 10, 2005 #13

    Monique

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    It need not be an evolutionary directed process, genetic drift can do that: as shown by the fact that the mentioned genetic diseases have a high frequency in the population.
     
  15. Jun 10, 2005 #14

    PerennialII

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    I'm getting interested whether I'm in the winning or losing team ... know any place where could take a look deeper at this or etc. information ?
     
  16. Jun 10, 2005 #15

    selfAdjoint

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    The paper says 80 generations under a gradient of this magnitude is enough. I think this will be the objection most often offered, but the discussion should address the specific quantitative points made by the paper.

    A good point. I am not expert enough to evaluate the Cochran et al. argument that this is adaptive, but perhaps you could look into the paper, Monique, and give your opinion of their argument?
     
  17. Jun 10, 2005 #16

    Monique

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    Yes, I'll look at the original paper when I have some spare time.

    An authority on the genetics of Finland is prof Leena Peltonen
    USE OF POPULATION ISOLATES FOR MAPPING COMPLEX TRAITS , Molecular genetics of the Finnish disease heritage , Messages from an isolate: lessons from the Finnish gene pool.
    Norio R has written a few papers in 2003 (you can find them on pubmed.com):
    Finnish Disease Heritage I: characteristics, causes, background.
    Finnish Disease Heritage II: population prehistory and genetic roots of Finns.
    The Finnish Disease Heritage III: the individual diseases.
     
  18. Jun 10, 2005 #17

    PerennialII

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    Thanks ! She's well represented & present in the media around here but haven't seen any "real" work of hers, I'll hook up with those papers.
     
  19. Jun 12, 2005 #18

    Evo

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    Tay Sachs gene may have prevented tuberculosis and therefore was a beneficial mutation in the Ashkenazi for that reason.

    Why Do Ashkenazi Jews Get More Genetic Diseases? The Beneficial Mutation Theory

    Other geneticists theorize that diseases in Ashkenazi Jews have arisen because of hidden benefits linked to the inheritance of a single copy of a mutant gene.

    People who carried the Tay-Sachs gene may have been resistant to tuberculosis.

    For example, people with one copy of the Tay-Sachs gene were discovered to be resistant to tuberculosis, a condition common in the crowded ghetto conditions in which Ashkenazi Jews often lived. Geneticists theorize that the people who carried the Tay-Sachs gene may have survived better under ghetto conditions, whereas people without the gene would be more likely to die. As a result, the Tay-Sachs gene continued to be passed on in greater numbers in the Ashkenazi population.


    http://www.genetichealth.com/BROV_Gen_Dis_in_Ashk_Jews.shtml#Anchor4

    Even more interesting is the fact that patients with Gaucher Disease are believed to have a special resistance to tuberculosis.

    Patients with Gaucher disease is believed to have a special resistance to Tb (this from a report of a patient that had Gaucher's and was also found to have TB, extremely rare).

    http://www.medicaljournal-ias.org/6_1/Uluhan.htm

    Tay-Sachs = resistance to tuberculosis

    Gaucher = resistance to tuberculosis

    Seems like the Ashkenazi's have developed genes that resist tuberculosis, one of the major threats to life when they lived in Europe and crucial to their survival.
     
    Last edited: Jun 12, 2005
  20. Jun 14, 2005 #19
    Just to stir the pot.

    How do we know which way the causal arrow is pointing here? The author makes reference to the link between banking jobs, IQ, and having babies. Maybe being wealthy provides both the health and spare time to learn. The small size of the gene pool is enough to explain the diseases.

    "Several studies have shown that intelligence, as measured by IQ tests, is highly correlated with income in jobs such as banking."

    Again there's a correlation here but I dont see the arrow of causality pointing from intelligence to wealth but rather from wealth to intellignece. Those with money have and will always be better educated than those without.
     
    Last edited: Jun 14, 2005
  21. Jun 15, 2005 #20
    IQ isn't something that you can gain or lose, it's more of an inhereted intrinsic quality.

    The paper claims, and gives much evidence supporting the fact, that the smallness of the gene pool isn't enough to explain the diseases. Can you counter the examples given in the paper?
    You seem to misunderstand the basic hypothesis. I'll try to reiterate it.

    Originally, the askenazi jews were not particularly brighter than any other group of people, and had essentially the same selective pressures that all other people living in the same places did. However, being that Christians thought jobs in money-lending were below them (becuase of how jesus went off on the money lenders), Jews were forced to do these jobs. Back in the middle ages, there was a high correlation between wealth and the number of children you had which could survive into adulthood. If you were wealthy, you could afford fresher food, cleaner habitation, wet-nurses for when giving birth and so on. The Jews in Europe that were bad at the jobs they were forced into could not make any money, and as a result, they and their families did not procreate as well as the smarter ones. Becuase the smarter ones could make more money and survive better, the cycle continued for hundreds of years until these particular pressures were removed.

    You again make the mistake of equating IQ with things like education. You're looking at it as if the Askenazi Jews were simply rich to begin with, and as a result educated their offspring to have high IQ's. But where did this original wealth came from? It came from unsucessful money-handlers dying off, and the sucessful ones living on.
     
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