Things Fall Apart: Greg Cochran’s New Theory of the Cause of Racial Differences in IQ

Steve Sailer, VDARE, July 17, 2012

Over at West Hunter, Greg Cochran has been introducing a fairly new and potentially important theory of the genetic origins of race differences in IQ. It’s less a theory of evolution than of devolution.

The mechanism causing effective differences, he argues, is less selection for higher IQ due to differences in the environment (e.g., winter versus tropics selecting for forethought); instead, a large driver is differential rates in random mutation leading to differences in average level of deleterious genetic load, which tend to correlate with climate warmth.


What would happen if people moved somewhere where the mutation rate was far lower?

Their genetic load would decrease with time, assuming that they were still subject to much selection. Today, everybody has hundreds of nicked or broken genes: selection keeps eliminating them, while mutation keeps creating them. The suspicion is that their effect is quite large. This hypothetical population would have fewer and fewer. In a few thousand years, they would lose most of the variants that decrease fitness by 1% or more.

Cochran’s next post looks at some data on the rates at which random mutations creep into the reproduction process.

Too Darn Hot?

Posted on July 14, 2012 by gcochran9

Several recent papers give me the impression that there is regional variation in mutational load. One can slice this a number of ways. Dan MacArthur and company looked for mutations that knocked out genes—loss-of-function or LOF mutations. Mutational load is the sum of all deleterious mutations – LOF mutations are a clear-cut subset of total mutational load.

Some of the LOF mutations they are found are common, and are presumably neutral, maybe even beneficial, but most are rare and likely deleterious. The kicker is that they found significantly more LOF mutations in their African population sample than in their European and East Asian samples – 25% higher. That was unexpected.

Population history (and mutation rate) determine the variation you expect to find in neutral genes, but significantly deleterious mutations should be in mutation-selection balance. A neutral variant might easily be a million years old, but a deleterious variant will last, on average, 1/s generations, when s is the decrease in fitness caused by that variant. A mutation that decreases fitness by 1% should disappear in 100 generations or so, about 2500 years. Ancient bottlenecks should not influence the frequency of such noticeably deleterious mutations.

Another related paper, by Jacob Tenessen et al, looked at a large set of coding genes, sequencing many times (average depth of 111x) for high accuracy. As in in MacArthur’s paper they found that the average person carries many probably-deleterious mutations, mutations which are individually rare. Each person carried, on average, mutations expected to change function (almost always for the worse, although usually only a little for the worse) in 313 genes (out of the 15,585 they studied.

They looked at African-Americans and Americans of European descent, about a thousand of each. They saw what MacArthur’s group did: there were significantly more probably-deleterious mutations in the 80%-African population. When they used a loose definition of functional variation, about 20% more : with a more conservative definition, which should have a higher fraction of truly deleterious genes, about 29% more.

… The only simple explanation (that I can think of) is a higher mutation rate.

One possibility is that heat tends to cause a higher mutation rate.
Henry Harpending then summed up:

Pre-term Births

Posted on July 16, 2012 by harpend=

The model that Greg is dancing around suggests (1) that there is variation in mutation rate dependent on temperature or something correlated with temperature, (2) higher mutation rates cause a higher genetic burden in human populations, (3) leading to IQ reduction and other minor dings

Here’s my model of this theory (which is probably pretty woozy):

Imagine, say, a factory that builds a complex product, such as a car, according to a complicated set of instructions. But, the instructions on how to build the next car are passed on via the Game of Telephone, with mistakes inevitably creeping in.

Sometimes, big mistakes are made, and the resulting car is such a disaster that it can’t function at all and has to be scrapped. But most of the individual mistakes are minor and just mean, say, that instead of delivering 268 horsepower, the engine generates 267.

Over time, the Telephone Game build up mistakes until a car is completely unusable and has to be scrapped. At that point the workers go find a better car and get the instructions for that car relayed to them. So, on average, most cars don’t come off the assembly line performing at spec, but they perform well enough to make it through a test drive.

Now imagine two factories making the same car from roughly the same overall design. One is in Nagoya and the other in Lagos. It’s so hot and humid alla the time in Nigeria, unfortunately, that the workers get distracted during their Game of Telephone and have a higher rate of errors when transmitting plans from one generation to the next.

In the comments, commenter extraordinaire Jason Malloy writes:

See these posts from February and April for the conceptual background.

While not fully or explicitly articulated, this is the first New Big Theory of race differences in quite a while, and an interesting alternative to the reigning sociobiological models available since the 1980s. In the latter models intelligence and reproductive differences are seen as consequences of natural selection in divergent latitudes, but this new model replaces natural selection with accumulated mutational burdens. The differences at lower latitudes are not selectively advantageous, but dysfunctional.

Dr. Cochran notes that complex adaptive systems, involving the functioning of many genes, should be the most vulnerable to genetic load, so this would obviously be the brain and probably reproductive physiology. So in addition to higher general mortality, dysfunctions associated with mutational burdens might include:

– Lower intelligence
– Higher retardation
– Higher mental illness

– Lower birthweight
– Higher premature births
– Higher infertility
– Higher reproductive deformities
– Higher miscarriage (and general obstetric complications)
– Lower sperm quality

Of course there is a difference between establishing population differences in genetic load, and proving that this is related to population differences in socially valued traits. I’m not sold on this as a replacement for sociobiological models, although there are aspects that make it useful and attractive in different ways. For example, I recently found that ethnic differences in rate of homosexuality are inversely correlated with latitude. Since theories of selectively advantageous homosexuality fall flat, this theory seemed like a better fit.

In the comments to Henry’s post, I offer a couple of tentative criticisms, which you can read there.

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  • I can go watch Swamp People, Lizard Lick Towing, Hillbilly HandFishin’ and all the myriad of anti-white shows from our friends in Hollywood –Oy Vey! And then I can listen to Morgan Freeman teach me about wormholes. The present state isn’t going to last much longer. Thanks to the internet, people are seeing the truths that were hidden from us for decades. We are dealing with animals.

    •  The funny thing is that the Swamp People and the Hillbilly Hand Fishers would last WAY longer in Africa than Morgan Freeman or any other African American for that matter!

      • I’d like to take Morgan Freeman’s teleprompter away from him, and then ask him to tell me all he knows about quantum mechanics. He would just stare blindly into space.

        • Unperson


          Morgan Freeman also narrated a penguin documentary. I’d like to see Old Brillohead tell us all he knows  — unscripted, of course — about that particular flightless bird. Or, for that matter, any other bird.

          (Oh, and Hollywood’s other big penguin movie of a few years ago was narrated by sassy, plus-size rapper Queen Latifah, who is of course another ornithologist of renown.)

          As for the out-of-Africa theory, it should be the friend of the white race realist. Yes, liberals will spin it as “We’re all from the same place so we’re all one people”; but we can spin it (much more persuasively) as, “We all began in Africa but the further a group got from there, the better they were forced to become (to survive cold winters, etc).” Certain black supremacists are fond of saying “Black Man, Original Man” but that’s really nothing to brag about. It’s the opposite of saying “New and Improved”: being the Original Man means you’re the LEAST EVOLVED Man. The least advanced. The most unimproved. The most backwards. The one closest to our ancient caveman ancestors…

          And therefore the one least compatible with modern civilization — as their behavior confirms on a daily basis.

  • WmarkW

     I don’t see this as advancing the argument very far.  In the environment where our most recent pre-human ancestors lived (Africa) there was the least selectivity pressure for characteristics necessary to humans to survive; but the variety of random mutations  that don’t eventually die out would be greater, because there’s no selectivity operating against them.  Hence, the indigenous peoples of Africa would show the greatest genetic variety, without that variety correlating with the ability to survive in different environments. 

    Whether the environment of Africa failed to select upwards, or tolerated selection downwards, either one explains environmental IQ selectivity equally well.   

    • Formerly_Known_as_Whiteplight

       It is more that the temperate climates in Europe and Asia required more intelligence to survive in.  Those Asian groups spread south in Asia later.  But this has been successfully argued for some time.  These groups had random mutations selected for survival in those conditions while the mutations selected for in Africa were for things like surviving malaria and running from lions, etc., although there were lions and tigers for Whites and Asians to run from too, just not as recently, and these two groups came up with better ways to avoid and fight these threats than Africans.  Negro genetic material is termed “most stable” because it is the most unchanged.

  • JohnEngelman

    Modern humans evolved in Africa 100,000 to 200,000 years ago. They were quite bit more intelligent than the Neanderthals living at the same time out of Africa. 

    • .

       While both of your claims may or may not be true I’m not convinced the evidence proves or disproves either at this point.

      • JohnEngelman

        The Neanderthals had a smaller tool kit than the Cro Magnons who displaced them, and whose ancestors had left Africa about twenty thousand years earlier. The Neanderthals, unlike the Cro Magnons,  did not seem to practice trade. They did not seem to be able to plan for the future.  

      • Formerly_Known_as_Whiteplight

         What John is forgetting or ignoring is the recent discoveries and evidence that Neanderthals were far more intelligent that previously thought.  They have also shown that it is likely that the infusion of their genetics into Homo Erectus resulted in an improved intelligence level and may account for the modern superior genetically inherited intelligence of Asians and Whites.

        • calvin

          These discoveries are “interpreted” as indicating that Neanderthals were more intelligent than previously thought. There is a new theory indicating that the Neanderthal was an apex predator, literally the stuff of human nightmares. 

          The presence of Ndt genes in Eurasians is evidence of a titanic struggle against a formidably strong and terrifying rival. This struggle itself was a massive selective factor. The conquest of the Neanderthal was the crucible that forge Eurasian man into the elite branch of humanity. the genes themselves are less significant than what their presence proves.

  • Guest

    Engleman, that out of Africa theory is totally unproven.  It is nothing but more anti White liberal propaganda.  How does the African theory explain why there are completely modern Asian skeletons dating back to 750,000 years ago? 

    • WmarkW

       Why is out-of-Africa anti-White propaganda?

      If that’s where our last pre-human ancestors lived, the environment there would exhibit the least selectivity pressure for characteristics correlated with adaptibility (i.e. the people who lived there would show the greatest resemblance to our pre-human ancestors).  The peoples who moved where the environment was least like Africa, would have been selected for greatest ranges of adaptibility characteristics; primarily, the IQ necessary to live in multiple environments.

      •  WHY is out-of-Africa anti-white propaganda?  Are you serious?  The liberal establishment uses this myth to bash us over the head with the club of equality.  If we are all “Out of Africa” we are all the same!  Our skin color just lightened a little because we weren’t under the blazing sun all day, but underneath that we are all the same because we all came from Africa.  Thus there are no “genetic” differences between the races that account for cultural and intelligence differences.  It is simply WHITE RACISM that keeps the blacks down (down from what, we do not know) because you see we are all africans!

        • WmarkW

           Being out of Africa is not a reason we’d all be the same.  The environment of Africa, the one in which our pre-human ancestors lived, allows the most primitive type of human existence to thrive.    Move that lifestyle to Manchuria, and only the smart ones will survive because they can figure out apatibility skills. 

          There’s no more reason to resist the idea that we’re descended from Negroids, any more than that we’re descended from something similar to a chimp, before that a fish, and before that an amoeba.  They’re all earlier stages of our development whose less desirable characteristics were discarded by evolution.

          • JohnEngelman

            The out of Africa theory angers those who would like to repeal the civil rights legislation because it asserts that their ancestors fifty thousand years ago would not have been served in Woolworth lunch counters in the South fifty years ago. 

        • JohnEngelman

          According to the out of Africa theory one hundred to several hundred modern humans left Africa 50,000 to 70,000 years ago. That is plenty of time for further evolution to have happened.
          Evolution did not really pick up speed until the beginning of agriculture ten thousand years ago, and the beginning of civilization five thousand years ago. Agriculture and civilization were begun in the Near East by Caucasians. About nine thousand years later agriculture was started in what is now China by the ancestors of the Chinese. Civilization there began about four thousand years ago.
          The Bantu, from whom American Negroes are descended, only began experimenting with agriculture about three and a half thousand years ago. They never developed indigenous urban civilizations with writing and mathematics. 
          Civilization and agriculture promote prolifically among those of superior intelligence, while removing those with criminal inclinations from the gene pool.
          Those who use the out of African theory to promote the liberal delusion that “race is only a social construct,” do not understand it. 

      • Greg West
    • alastairabbacle

      I can’t wait until China blows up the entire world genetic egalitarian paradigm.

      Pretty soon, they will tell White nations to make more babies, just to have people to think of more ideas.  Or they will infuse White genes into their own genes, via the reimportation of all Eurasians.  That is to say, they will give financial incentives for American Eurasians to settle in China.  Maybe, unless their own birth rate gives out….. I just keep hoping that the world can save itself from the lowest common denominator genetic oblivion.  For all races, even the Negro. 

      • JohnEngelman

        June 29, 2010 
        SHENZHEN, China — Last year, Zhao Bowen was part of a team that cracked the genetic code of the cucumber. These days, he’s probing the genetic basis for human IQ.Zhao is 17.Centuries after it led the world in technological prowess — think gunpowder, irrigation and the printed word — China has barged back into the ranks of the great powers in science.

        With the brashness of a teenager, China’s scientists and inventors are driving a resurgence in potentially world-changing research…

        But over the past five years, Western-educated scientists and gutsy entrepreneurs have conducted a rear-guard action, battling China’s hidebound bureaucracy to establish research institutes and companies. Those have lured home scores of Western-trained Chinese researchers dedicated to transforming the People’s Republic of China into a scientific superpower…

        In 2007, Chinese geneticists discovered vast differences in the genetic makeup of Africans, Asians and Caucasians. 

        • alastairabbacle

          That is very cool, John.

          What I am fascinated with is the idea that civilizational progress can be unleashed with an alignment of practicality and philosophy.

          At this moment, were China to imbibe to political philosophies of John Locke, it would take off.  Confucious/Mencius does not conflict with John Locke’s philosophy, but rather, this philosophy would unleash the true power of Confucionism.

          The genetics of Chinese are held back by Marxism bound Confucionism.  Already, we are seeing the unleashing by Lockianism.  
          One could suggest that the union of Jesus and Confucious will provide the philosophical foundation, for a genetically uplifting, market-forces based civilizational uplift.  

  John Locke  +
         Mencius +

          Clever Genetics

          =Civilizational Prospering

    • JohnEngelman

      Do you mean Peking Man? Those skeletons were not completely modern. They were Homo Erectus. The out of Africa theory is the scientific consensus based on DNA evidence and paleontology. 

      • alex

        The smart ones left Africa.

  • alastairabbacle

    Here is a race realist blog by a Negro, “Jayman”.

    It is interesting to witness the increasing proliferation of Black race realists, especially on “the game” dating blogs.

    Please compare and contrast the following two maps:

    Black IQ by State:

    White IQ by State:

    There are many smart Blacks out there, we just need to encourage them.  Not discourage them.

  • alastairabbacle

    Blaack Obongo, 

    This issue becomes:  What do you want to do about it?

    If you support America, than you support the improvement  of the Black population.  
    If you are a racist who wishes ill on your fellow humans, then you support the continued degradation of Blacks.

    I just do not know what to do about complainers.  I could sit here and whine about Blacks all day, and it will change nothing.  What needs to change is the evolutionary holding back of Blacks by the liberal establishment.   You certainly do not wish to alienate a population who resides in all major US cities, do you?  The solution will be imperfect, there is no such thing as a final solution.  You cannot achieve an ideal with the Black population, they have their own unique gifts and serious setbacks. They know.

    • alex

      You are delusional.
      You can establish new policies in a zoo. It won’t make wolves and bears behave like herbivors.
      There is nothing wrong with being a racist.

      • alastairabbacle

        You are right about the fact that you cannot make wolves and bears behave like herbivores.  


        “Ample evidence is provided in this book and its citations to support the conclusion that race is real, not a delusion concocted by evil racists. But that same evidence raises another question: Is the evidence adequate to classify Africans not just as a different race, but as a different species, Homo africanus?”

        However, given that Homo africanus is here to stay, I wish them to be as little a nuisance to European Americans as possible.

        This means that the goal for Homo africanus should be for them to be a smart and peaceable as possible.  Under current liberal PC policies, none of this is possible. 

        • alex

          No policy will make one smart. It’s possible to force one to be peaceable by fast, brutal and public punishment. 

      • alastairabbacle

        BTW, lol at this Single Mother with Black Children:
        From the New York Slimes “Single but Unequal” (lol) series:

        People DO need to learn not to create ligers and mules.

  • Guest

    I’m an atheist, but I don’t buy classical or neo-Darwinism. Evolution has obviously taken place; I just don’t think any current theories explain how it works. I became a Darwin skeptic after reading a fantastic book called “Darwinian Fairy Tales” by the great Australian philosopher David Stove, who was also an atheist, BTW. Highly recommended.

  • Church_of_Jed

    GOP faithful use polling to prove their commitment to the  UnDoing of White Privilege

    Embarrassed that White Privilege Romney isn’t far behind in polls

    Worries about charges of “racism” if Romney keeps up momentum

    “Another White president is a step in the wrong direction- we’ve overcome too much White privilege to go back now- America is better than it was before MLK refounded it, and we just can’t afford another White president- maybe Condi can save America by costing Romny the election- Condi for VP!”

    Poll: Rice top VP choice of Republican voters…


    Tied in VA…