Society and Culture

The Debate about Heritability of General Intelligence Radically Narrows

A landmark article went online a few days ago in the journal Molecular Psychiatry. The study was prepared by a team of 32 researchers headed by the University of Edinburgh’s Gail Davies and entitled “Genome-wide association studies establish that human intelligence is highly heritable and polygenic.” The study’s methods do not lend themselves to easy explanation unless you’re at home with SNPs (single nucleotide polymorphisms) and inverse variance weighted models used to capture “the variance in the trait that is due to linkage disequilibrium between genotyped SNPs and unknown causal variants.” But the bottom line of the article is reasonably simple. Using nothing but genetic information, the team of researchers was able to establish that the narrow heritability of crystallized intelligence (the kind that can be more easily affected by education) is at least 40 percent. The narrow heritability of fluid intelligence (the kind that involves pure problem-solving ability, independently of acquired knowledge) is at least 51 percent. Note the at least. The study’s authors explicitly state that these estimates are lower bounds.

Shelves of books and articles denying or minimizing the heritability of IQ have suddenly become obsolete. Those who continue to claim that IQ tests don’t measure anything real inside the brain also have their work cut out for them.

24 thoughts on “The Debate about Heritability of General Intelligence Radically Narrows

  1. Guess it is time to pull my copy of “The Bell Curve” off the shelf and re-read it. Amazing how, given time and study, ideas that are dismissed (by the MSM) are shown to be true.

  2. I’m wondering if the results from this study supported Dr. Murray’s conclusions in earlier works about IQ and race…?

  3. “I’m wondering if the results from this study supported Dr. Murray’s conclusions in earlier works about IQ and race…?”

    No, the study participants were all white.

    However, it would be easy to test whether genes contribute to the black-white gap by using modern DNA-based methods. No one has published such a study so far.

    • “However, it would be easy to test whether genes contribute to the black-white gap by using modern DNA-based methods. No one has published such a study so far.”

      Right. They look back on Murray & Herrnstein’s experiences and think, “Do I want to subject myself and my school and my colleagues to the kind of abuse that will surely come?” Seems to me the answer is self-evident.

      • Mr Geneticist, you are wrong. It is indeed possible to test it using current technology. In fact, Charles Murray himself pointed this out several years ago. However, it may be that it is only possible as far as African Americans and other admixed black populations are concerned. The method consists of estimating the extent of white ancestry in African Americans (a trivial feat these days) and then correlating it with their IQ scores. If the correlation is linear and positive, it means that white ancestry boosts IQ in blacks, indicating that the b-w gap is at least partly genetic.

    • all white means nothing. there are differences among white scots. the irish of glasgow are lower class compared to the native scots. highland scots tend to have dark complexions and tend to be ridiculed for their accent by lowland scots. scots in the outer hebrides still speak gaelic.

      UNLESS THE POPULATION IS HOMOGENEOUS TWIN STUDIES ARE FAR SUPERIOR TO THE STUDIES OF THE ABOVE KIND.

  4. No, Timothy Thomas, they do not. This article is about the heritability of IQ, not on the differences in mean IQ scores between races. Intelligence is a multi-faceted issue, you know, not just race, race, race…

  5. Based on Murray & Herrnstein’s own experience over the last 40 years, and Moynihan’s if you want to go back even farther, if this study rises to the MSM’s attention, the authors are in for a public assault on their characters and their research such as they have never seen before.

    The poverty- and race-pimps will come flying out of their Diversity Offices next door to the CEOs, Deans’, and Directors’ offices and begin a media campaign the authors will be lucky to survive professionally.

  6. All IQ test questions can be performed more easily with practice, as practice makes perfect.

    IQ test questions are not fundamentally different from other questions in that sense and so the people who select the types of questions may introduce a bias based on what questions were easier to answer for them.

    I can imagine the types of questions people in academia would select would also be more geared to the ways of thinking in academia and the problems they need to solve exactly.

    In the extent to which brain power is like computer power, someone with the same brain power might have a significantly lower IQ based on these tests if for example they spend their brainpower mostly trying to solve vastly different problems in their day to day lives like analyze social situations, processing audio/visual information quickly, or processing lots of different concerns in less detail then people who need specific rigorous solutions.

    Time spent improving performance on one problem necessarily means less time improving performance on another problem.

    There are probably differences in brainpower. Perhaps IQ is the best easily testable measure, but it’s not a good one.

    • ” Perhaps IQ is the best easily testable measure, but it’s not a good one.”

      That is simply wrong. There is a vast amount of data showing that IQ tests correlate quite well with intelligence.

      • iq is the best possible measure or operationalization of “intelligence”, but it sucks in america more than anywhere else except canada.

        in the rest of the world, with the exception of canada, cumulative exams determine what uni you get into and what the quality of your uni degree is. not in les etats unis merdeux.

        a battery of gsces and a-levels are as g-loaded as the sat, BUT in LES ETATS UNIS MERDEUX ONE MUST ALSO BE AN OBEDIENT PUSHY C*** AND HAVE RICH PARENTS TO GET INTO AN ELITE SCHOOL.

        MY DAD WENT TO HARVARD. HIS DAD STONYHURST AND PRINCETON. DID I? NO. MY HS WAS TOTALLY INEXCUSABLE.

  7. Dear Dr. Murray,
    I am intimately familiar with your article in the COMMENTARY magazine and share your ideas about the heritability of intelligence. Furthermore, I acknowledge and cite your basic thesis. However, unlike you, I believe that high intelligence among the Jewish people did not arise because of selection, but gradually accumulated in a series of approximately 100 generations in the process of intensive study of religious texts. At the same time, in my reasoning, hereditary transmission of acquired characteristics played a leading role. For this reason I wrote the article, unfortunately, in Russian, and placed it on the website http://www.elektron2000.com/shlyankevich_0245.html and the original of your article was published here too http://www.elektron2000.com/av_murray.html . At the request of the editorial board, along with my article placed the Russian translation of your article Jewish genius.
    Sincerely yours,
    Mark Shlyankevich, M.D., Ph.D. Yale University School of Medicine (retired)

  8. i really can’t believe how stupid this post is. but then again i’m a subject of the bgi study.

    who were the subjects? where did they come from? the heritability is not one figure. within any environment or range of environments one will find genes, thousand of genes, which affect the iq, BUT those genes may not be the same from one environment to another AND the heritability figure will vary.

    UNTIL THE SUBJECTS ARE REPRESENTATIVE OF ALL ENVIRONMENTS EACH WITH AN IQ SCORE FROM A TEST TAILORED TO HIS ENVIRONMENT ALL THESE STUDIES ARE…

    MEANINGLESS!!!

    FOR EXAMPLE, THE RISK FACTORS FOR CVD ARE AS HERITABLE AS IQ YET WITH ONE VERY SIMPLE INTERVENTION THEY ARE MADE OPTIMAL. http://www.pnas.org/content/101/17/6659.long

    THE NEW LYSENKOS ARE THE HEREDITISTS. THEY ARE TO NEO-LIBERALISM WHAT LYSENKO WAS TO STALIN.

    • “tailored to his environment” means that the WAIS, etc. given to a new guinea highlander is neither going to reveal his native intelligence nor his standing relative to others of his type very well.

      not even the non-verbal subtests. this was demonstrated in the afrikaner british south african difference. the difference was all in the non-verbal tests, and has been erased in 50 years.

  9. “Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence.”

    these authors are dummkopfs. it’s always amazing how some people can do quite complicated things yet CAN’T ever “get” some subtleties. if all of their subjects were from around edinburgh their results are less than meaningless. YET THEY GENERALIZE TO ALL HUMANITY IN THE ABOVE QUOTE.

    IT’S A REALITY: THE PEOPLE DOING THIS RESEARCH ARE TOO STUPID TO DO IT.

    besides, the crystallized/fluid dichotomy was shown to be ROT in the following study: http://blogs.scientificamerican.com/beautiful-minds/2013/10/17/the-heritability-of-intelligence-not-what-you-think/.

    most heritable and most culturally loaded and most g-loaded and most reliable = vocab!

  10. another NEVER made point is the meaningless of this research EVEN to those with high IQs in edinburgh or wherever the subjects came from.

    it has also been found that g is what is heritable in all cognitive test scores YET g explains a smaller and smaller % of test score variance going up from low IQ to high IQ (spearman’s law), so that at high IQ it explains less than 1/3.

    AND on top of that, given a heritability of .68 for adults, if you have a score of 160 the likelihood your twin will score lower is 96%!

    THAT IS, THE HIGH IQ SORT WHO (I SUPPOSE) READ MURRAY SHOULD KEEP IN MIND THAT THEIR GENETIC “TRUE SCORE” IS ALMOST CERTAINLY MUCH LOWER.

  11. and again before my comments are deleted, i am a paticipant in the bgi study. my sat, cbats, act, BUT not my gpa were above the mean of those ADMITTED to harvard, cal-tech, every school in the country. BUT did i get into a school in the 99th percentile? NOT in this shithole of a country.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>