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IQ, Intelligence, Ethnicity & Gender

Published by Edster900 in Offbeat
August 22nd, 2009

Mainstream concepts and studies of IQ and intelligence attempt
to explain the nature, origins and practical consequences of
individual and group intelligence. The problem with these
explorations into the human intellectual machine is that they
are generally biased and stereotyped, depending upon a model
which is culturally incomprehensible to many Third World
people, Africans in particular.

I n a statement signed by Raymond B. Cattell, Hans Eysenck, Arthur R. Jensen and Richard Lynn, all eminent professors and experts in the field of intelligence and IQ testing, they concur that the definition of intelligence is “general mental capacity that involves the ability to reason, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience.” These gentlemen agree that intelligence is not merely book learning or test-taking smarts; rather it reflects a broader and deeper capability for comprehending one’s surroundings. It is important to realize that “catching on,” “making sense” and “figuring out” are the key factors in “intelligence.” The professors also agree that IQ tests measure this general ability, and that most standardized IQ tests measure more or less the same traits – so far so good! However, they overemphasize the role genetic factors play in the measurement and understanding of human intelligence. According to these men and 48 other signees of the approval of the conclusions of the book  The Bell Curve,  Blacks are doomed to be less intelligent than Whites and Asians. The group further declares that there is no convincing evidence that the IQ bell curves for different racial groups are converging. In unison they affirm that there is no definite answer as to why IQ bell curves differ across racialethnic groups. Could it be that IQ tests themselves hold the key to this problem…? Is it really “genetics” that explains why a hungry child in Ethiopia or young student in some war-torn area of the globe does not learn math and language as well or score as high on an IQ test as his counterpart who lives in a good neighborhood in the socalled First World, is at peace with himself and his environment, has the benefit of a decent education and parents who can care for and tutor him? The signees believe that research on matters of intelligence relate to some  unclear  social and primarily biological  distinctions. A phenomenon known as the Flynn Effect may reduce or eliminate differences in IQ between races and cultures in the future. With IQ scores in affluent Holland and Spain up by 6–8 points, respectively, in just one decade and an astonishing 26- point increase in the past 14 years in developing Kenya, it is evident that the Flynn Effect is a reality and that genetic bias against Blacks does not carry any weight. There is, in addition, an argument that the average IQ of the United States was 75 before improved nutrition increased the scores of the general population. (The IQ for the average American is currently 98.) It is almost universally agreed upon that a person’s IQ can predict academic success, but not how to function successfully in one’s environment. Furthermore, there is considerable evidence from re-testing and the application of different tests that a person’s IQ does not remain fixed over his  lifetime.

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  1. Posted August 22, 2009 at 10:38 am


  2. Jay
    Posted October 18, 2009 at 6:38 pm

    “A phenomenon known as the Flynn Effect may reduce or eliminate differences in IQ between races and cultures in the future.”

    Wicherts et al, have noted that the Flynn effect appears to have few implications in relation to group differences. The Flynn increases are largely domain specific.

    There appears to be no closing of the gap between East Asians and europeans, while Ashkenazi Jews average 2/3 of std deviation above other europeans. These statistical differences show no sign of changing.

  3. Jay
    Posted October 18, 2009 at 6:39 pm

    “generally biased and stereotyped”

    This has been investigated and found to not be the case. For instance, Raven’s Advanced Progressive Matrices have the same predictive value across cultures. This has been looked at by Jensen in ‘Bias in Mental Testing’.

    An example is on forward digit span memory groups score about the same. However, on the more cognitively demanding task of repeating a sequence of digits back in reverse, group differences increase.

    The National Academy of Sciences looked at Jensen’s claims that tests had equal validity across groups and found he was correct. This was also the finding of the APA Taskforce on Intelligence: Knowns & Unknowns which investigated the findings of the Bell Curve. More recently Robert Sternberg has written about the cross-cultural validity of testing.

    There are also a number of biological correlates with performance on tests. A basic example is reaction time measures. East Asians, who have long been noted to outperform europeans on average on tests, also outperform them on the reaction time measures.

    An indication that a trait is inherited on dominant genes is provided when trait levels are reduced by cousin marriage a phenomenon called inbreeding depression. Some mental tests show more inbreeding depression than others, and it is mainly these tests which show the biggest group differences in performance levels.

    There are other brain characteristics that vary in those who do well on the tests. These include, cortical thickness, myelination (this insulates neurons & affects processing speed – Einstein had an unusually large ratio of glial cells which produce myelin) & gray matter volume.

    For a summary of the neurobiological correlates with ‘g’ see this summary by UCLA neuroscientist Paul Thompson & Yale Psychologist Jeremey Gray:


    These factors appear to be significantly heritable.

    “IQ inheritance: By comparing the brain scans of twins, scientists discovered that the quality of the fatty tissue that insulates neural wires is largely inherited. The parietal lobe, which is involved in logic and mathematics, is 85 percent genetically determined, whereas the visual cortex is about 76 percent, and the temporal lobe, which is involved in learning and memory, is only 45 percent genetically determined.”


    “A substantial body of literature from twin, family and adoption studies documents significant genetic effects on human intelligence. Heritability estimates range from 40 to 80% and meta-analyses suggest an overall heritability of around 50%”

    Dick et al, (2006) “Association of CHRM2 with IQ: Converging Evidence for Genes Influencing Intelligence.” Behavioral Genetics.

    “Multivariate genetic analyses indicate that general intelligence is highly heritable, and that the overlap in the cognitive processes is twice as great as the overall phenotypic overlap, with genetic correlations averaging around .80.”

    Plomin et al (2004) “A functional polymorphism in the succinate-semialdehyde dehydrogenase genes is associated with cognitive ability,” Molecular Psychology 9, 582-586.

  4. Rechill
    Posted June 13, 2010 at 10:09 am

    Why would it be such a surprise that a Nigerian scientist has an IQ of 190? It\\\’s called a Bell Curve for a reason. It\\\’s not that it is impossible, just statistically rare. Any mention of differences in average IQ\\\’s among races brings out such histrionics. Grow up.

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