Human Genetics and Social Theories

It has been a lively week on this blog. “DAD” and Razib Khan have challenged our (Michael Scroggins and myself) basic competency to discuss genetics and race/intelligence/etc.   We have responded with similar incredulity to their ability to critique anthropology.

 

In other words, we in the social sciences think they are naïve, and they think we are dunderheads.

 

This overall does not seem to be a very productive set of assumptions to go forward with; Razib and DAD actually appear to be relatively well-read people, though clearly we do not read the same things.  So what I propose here is that each of us propose what books/readings would be part of a graduate “Human Genetics and Social Theories” class.  I will start, while knowing that what I propose will probably annoy the geneticists (I guess I already have at some level).  They should feel free to call me on my naivete without concern:  I am a tenured full-professor fully capable of taking critique. Likewise the last Genetics course I took was in 1979 which was really a long time ago.  My last Anthropology course was about 1991.  Anyway, here goes some initial suggestions:

 

1)  Stephen Jay Gould, The Mismeasure of Man (and yes I know that Gould has been accused of mis-representing his data)

 

2)  Jonathan Marks What it Means to be 98% Chimpanzee

 

3)  Michael Young The Rise of the Meritocracy, 1870-2030

 

4)  And because I really don’t like the misuse of psychometrics: Ross Douthat, Privilege: Harvard and the Education of the Ruling Class, Daniel Golden, The Price of Admission: How America’s Buys its Way Into Elite Colleges, and Nicholas Lemann, The Secret History of the American Meritocracy.

 

5)  Durkheim on religion social groups

 

6)  I’m open to parts of Jared Diamond’s Guns, Germs, and Steel (and Collapse), and Steven Pinker’s new book on violence.  Both Diamond and Pinker are in places quite good (though I’m critical of Pinker’s socio-biology which appears in the latter part of the book, and Diamond’s forays into using his data to advocate social and economic policies).

 

7)  My own critique of how geneticists use data from the Mlabri, which are here and here.

 

8)  Reviewing psychologist Donald Campbell’s critique of the misuse of quantitative data is always a good idea too.

 

Ground rules for proposing readings:  Please avoid charges of racism, general fraud, left-wing creationism, and so forth when it comes to the people commenting.  If you want to call the authors of the books proposed by these names, it is fine with me.  Idiot and moron are out though, since they are archaic psychological a terms (see Gould).  If you want to call me crazy, though, that’s fine.

 

Please try to stick to questions of scholarship, and focus on advocating your own proposals, though of course brisk critique of others is welcome.

 

Anthropologists might keep in mind what John Hawks recently wrote on his blog:

 

Like any radicals, [anthropologists] weren’t always right. Any working scientist will be wrong about most of the details, if we revisit his work after fifty years. What makes anthropology weak today is that so many anthropologists learn nothing about scientific anthropology after Boas. They’re reactionaries against science, without knowing what today’s scientists do.

 

[But] consider our scientific history. With sheer empirical observation, anthropologists unshuttered the folds of humanity, raising people who had been derided as “primitives” up to their rightful place beside the pampered dons of Western culture. In so doing, their science transformed “civilized” culture itself….

 

We can be part of the future by reinvigorating anthropological science and by developing a deeper conversation with other scientists outside anthropology. Tomorrow’s anthropologists must know the field’s successes as well as its failures. The way to combat bad science is to do better science.

 

What I am hoping for is that “deeper conversation” Hawks writes about.

 

As for what Geneticists want to keep in mind…I’ll leave that to Razib or DAD to provide!

42 Responses to “Human Genetics and Social Theories”

  1. dad says:

    I’m not sure if I’m qualified to make a suggestion but I’m flattered you included me:) I will humbly suggest “Before the Dawn” by Wade and “The 10,000 Year Explosion” by Cochran, Harpending. Thanks, Tony!

  2. dad says:

    I forgot to add that I chose these books because, although controversial, they are engrossing overviews that will at least plant a seed from the Dark Side in the students’ minds. At least let them know that this research exists.

  3. Tony says:

    I read Wade’s book a couple of years ago. It has the advantage that it is well-written, and as you point out, tends to set anthropologists off because of its socio-biology. If I remember correctly, when I read it, I think my thought was that it was a good summary of the state of the research from that perspective. I also remember being critical of how he developed the points about brain plasticity, as I was writing a paper about “mirror neurons” at the time.

    How do you respond to the critiques of Wade? I haven’t read “The Ten Thousand Year Explosion.” What is the take of this book?

    How important is Cavalli-Sforza in Genetics?

    As far as I can tell, no one is really qualified to come up with this list–if that were the case, we wouldn’t talk past each other so much. (I included John Hawks evaluation of how poorly anthropologists have engaged with Science for the last few decades for a reason!).

  4. razib says:

    cavalli-sforza is still a giant in human genetics. his active career is over, but many of the great human geneticists today are his intellectual descendants or collaborators.

    just read *principles of population genetics* by dan hartl and andrew clark. it’s a textbook, but my problem with ignorant anthropologists has more to do with a deficit of textbook knowledge than the facts.

  5. Sam says:

    The Mismeasure of Man is a long, rambling cavalcade of non sequiturs, strawman arguments, and shameless distortions of the psychometric literature. Then again, that pretty much captures the entirety of Gould’s career. Gould isn’t respected by mainstream evolutionary biologists, for one. But his sordid legacy should continue to endure long after his death — when you wish to establish a reputation that forever poisons the academic zeitgeist, it helps when you say things that make social scientists feel warm and fuzzy inside, but truly have little basis in reality.

    Gould spends countless pages obsessing over the notion that brain size in the human species in hard to measure, and poo-poohs the low correlations that early anthropologists have found between cranial capacity and IQ. (Which typically ranged from 0.1 to 0.2.) Absolute horse crap. Samuel Morton may have had to make do with bird seed and shot, but we’ve had MRI machines since the seventies. We have studies from the _seventies_ reporting correlations between 0.4 to 0.5 between brain size and IQ among college students — (and that correlation would presumably be higher, if we could measure subjects outside the normal range, such as microcephalic patients). Gould sure knew about these, but strangely declined mentioning them in the first edition of TMOM or in the 1996 reprint.

    Oh, and by the way, there are indeed differences in average brain size between different human ethnic groups, and they don’t disappear when you control for body size. This isn’t phrenological hokum, either — it has been confirmed by modern anthropologists who have no sympathy whatsoever for scientific racism. Average cranial capacity among human ethic groups ranges from _three_ standard deviations from the Inuits down to the Australian aborigines, following a biological cline from the arctic circle to the torrid zone. Samuel Morton never falsified any of his data, and Gould lied to convince others of his falsehood.

    (None of this, of course, proves that ethnic differences in brain size have anything to do with genotypic intelligence — for one, brain size among _all_ human populations has declined by over 10% since the beginning of the current interglacial, yet the Scientific Revolution took place during the past five hundred years, not during the Paleolithic. Gould could have pointed that out, instead of spinning yarns about Eurocentric bias having irredeemably corrupted the human sciences.)

    By the way, if there isn’t any correlation between brain size and intelligence, how the hell did the environment select for higher intelligence among anatomically modern humans by increasing their cranial capacity? It is truly baffling how many anthropologists believe in the inverse. If there were no correlation between human cranial capacity and intelligence, and if the heritability of brain size were _zero_, we would have to conclude that natural selection was false, and that the human species came into being through intelligent design. Yeah, I’m sure we could have taught the Taung child how to solve differential equations if we had provided him a really good tutor.

    Back during the 1970s, psychologist Leon Kamin lead the charge that Cyril Burt had falsified data from twin studies alleging that the heritability of IQ was 0.77. (Today, it is not clear that Burt lied about anything, and the accusations of fraud by his detractors amount to little but circumstantial evidence, but that is beside the point.) In his book, Gould naturally harps upon this dictum as if it forever eliminates the notion of hereditary intelligence. Well, isn’t it just strange that the Minnesota Twin Study published a full _two_ years before TMOM largely replicated Cyril Burt’s findings, almost down to the last digit?

    Even worse for Gould — similarly high measures of broad-sense heritability for _adult_ IQ have been replicated everywhere from Sweden to Japan and beyond, and they are largely consistent with similar figures from adoption studies. (No mention of this, by the way, in the second edition of his book.) Neither do they contradict some of the recent findings from GWAS studies, which carefully eliminate some of the alleged sources of error in the classical twin study design.

    That doesn’t even begin to cover Gould’s distortions of the psychometric literature, his vulgar caricature of the history of IQ testing and the eugenics movement (e.g. Jews scored higher than white gentiles on IQ tests even during the 1920s, and the “vicious racist” Goddard was one of the first to publicize this fact), his routine poisoning of the well by appealing to Nazi atrocities (both Hans Eysenck and Arthur Jensen were Jewish), and his brazen disregard for scientific honesty and rigor. I could write about this at length if I wanted to, but I just don’t give a damn. Psychometrics isn’t even taught at my university, largely for political reasons, and due to the explosive nature of IQ testing, it’s not likely that we will ever have an honest discussion about the measurement of human intelligence in the near future.

    Oh, and by the way, if you happen to love what Stephen Jay Gould has to say about psychometrics, you’ll _really_ love what the American Psychological Association had to say about the Bell Curve.

  6. dad says:

    Sam pretty much sums up my views on Gould:) You can get a pretty good sense of what to think about Wade and 10,000 Years from reading reviews on Amazon and their respective wiki pages. I think there can be legit criticism any time you’re covering that much history but those books at least attempt to address unpleasant realities like human differences and religion in an honest way.

  7. Tony says:

    Thanks for all the interesting posts, especially the long one from Sam about Gould. I’ll deal with different points in separate postings, but first the point about psychometrics and Gould.

    I know that Gould is controversial in his own discipline. Believe me, The Bell Curve is controversial in the Social Sciences. Do you really believe that The Bell Curve should be part of a graduate level reading list? I’ll make you a deal: I’ll give you Gould to tear apart, if you’ll give me The Bell Curve!

    The critique of psychometrics and the testing industry though go way beyond Gould. I included Nicholas Lemann’s book about the “secret” history of IQ testing as one example. Also Daniel Golden’s book The Price of Admission, which is about how the SAT and other variations on IQ tests are routinely gamed. My favorite critique of the psychometrics industry comes from the mathematical psychologist Donald Campbell which says: “The more any quantitative social indicator is use for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor.” Basically this means that any statistic that is used for administrative purposes and the distribution of rewards tend to be corrupted.

    Anyway that’s my two cents about Gould and psychometrics for now. I’m off to the library to see what the Population Genetics text Razib mention has to say about the relationships between ethnic identity, language, and genes (I hope they have a copy here in Germany). I’m also going to see of one of Cavalli-Sforza’s big books are over there–I last looked at that about 10 or 15 years ago, I think.

    Michael Scroggins cited publications about how the definitions of the gene have changed since 1910. Do you (Razib, Sam, or dad) think that such a discussion is relevant to genetics today? What abou the Boas made of the “science” of race in the early 20th century? John Hawks mentioned this in his posting, and I suspect Michael knows more about this critique.

  8. dad says:

    The last two questions are a little above me but as far as psychometrics and the Bell Curve go I don’t quite know what else to say! Anyone can go on mensa’s site and take an IQ test – this is pretty well established stuff. Even school board members who are hugely invested in improving urban test scores know very well you can use many different test to show an individual’s problem solving ability. Questioning it too much is kinda like questioning the 100 yard dash’s ability to measure running speed.

  9. dad says:

    If nothing else, I vote for at least showing them the YouTube clip of the Silver Fox experiment. Once one sees that there’s pretty much no going back:-)

  10. Tony says:

    What is the Silver Fox experiment? Remember we travel in different universes–I’ve never heard of it.

    Regarding intelligence: It is always measured relative to a pre-existing standard of what is smart or not. Mensa probably does a pretty good job of testing for what is smart in modern culture. But the Mensa test itself is a product of this culture, and measures things only relative to…this culture. In other word, it is circular.

    What would happen if we took the person with the highest i.q., and transported them to and African village where “intelligence” is measured by the capacity to track and kill a lion with a spear. The Mensa guy would be literally eaten for lunch, while the illiterate tracker could very well be collecting his cows for having killed the lion.

    Ok, that’s an extreme example. But it would also apply to living in a Thai village, Inuit village in Alaska, Central American village, or any of the thousands of societies which value things cognitive skills Mensa does not test for.

  11. Tony says:

    @dad Could you please post a link to the “Silver Fox Experiment?”

  12. Sam says:

    Tony, this isn’t to say that all is well on the other side, or that there aren’t serious methodological flaws in the practice of evolutionary psychology, behavior genetics, or whatever have you. (By the way, the last time I checked, neither fields agree on much of anything – there truly isn’t a unified front of reactionaries who agitate day and night for the desecration of your discipline.)

    I have much more to say about psychometric, eugenics, and the Bell Curve, but that will have to come later.

  13. Michael Scroggins says:

    Gould poses two philosophical problems for population genetics that a narrow reading of Mismeasure of Man fails to capture.

    First, Punctuated Equilibrium posits that stasis is the default state of change in evolution. That is, change mainly happens in great bursts which create immense morphological variation (speciation) for a short period of time. Following this things settle into a long period of stasis. There may be some variation in phylogenetic change, but it has no real physical or functional importance – though we all know it has tremendous social importance. This is well supported in the fossil record.

    Obviously this is a great difficulty for any field which posits gradual phylogenetic change as the main mechanism of evolution, and then seeks to rank groups accordingly.

    The second challenge Gould poses is simpler. Where in population genetics (particularly historical population genetics) is the theory of development?

    What it has is a variation of recapitulation theory. Embryonic members of a given population are assumed to develop unproblematically into adult members of that population.

    How do you move from the gene (pick a definition) or some sub-part of the gene to the development of an individual within a social milieu? From the unit of analysis taken by population genetics (some part of a gene) you simply cannot make assertions about complex phenomena like the display of “IQ.” Though that has never stopped some of them from trying….

  14. dad says:

    http://www.youtube.com/watch?v=EoB0pdhxfZs

    Idk Tony, one culture is on Mars and the other is still throwing spears and yet it’s all relative?? Idk what to say! You’re just a nicer guy than me, I guess…

  15. dad says:

    And that’s not to mention that you can take Asian babies and raise them in a white culture and they’ll still have higher IQ avgs than the natives, etc.

  16. Tony says:

    I don’t know about adoption studies of Asian babies raised in the US with a good control. Maybe it is out there. But my impression is that the capacity to do math, literacy, etc., are pretty malleable. Three generation ago, China was known for illiteracy, etc. Japan was also a violent society in the 1920-1945, and extraordinarily peaceful today. In my way of thinking this points to the centrality of culture in both establishing what is “intelligence” and then raising children to meet that standard.

    I enjoyed the film about the silver foxes, and think indeed it has something to say about the domestication of dogs who are intensively bred for 50 (?) generations. Fortunately, humans are not bred for that many generations in this fashion. In addition they have culture which is far more malleable than genetics. In short, if you want to understand human populations, you need to understand culture. Evolution is far to clunky to result in the changes in learning, technology, religion, emotions, etc., that have occurred over the last 500 or even 5000 years for genetics to explain all this.

  17. dad says:

    Yeah I’m not suggesting genes explain everything but the video does clearly demonstrate that genes influence more than most realize. All one has to do is look at any person with a single gene defect to see how profoundly it can effect intellect and form.

  18. dad says:

    I can’t tell you what to think, I’m simply suggesting that it seems overwhelmingly unlikely for anthropology to be able to explain away every single unpleasantry..without even knowing they exist. Trust me, I used to be liberal!

  19. Tony says:

    Nope, anthropology can’t explain away everything, pleasant or unpleasant.

    Gene mutations do indeed profoundly effect the lives of individuals. But the bigger question is how much do they effect populations, and the course of history with respect to violence, etc. My answer so far: Not much. Greed and culture explain much more!

  20. dad says:

    U sure? I could have sworn there is a little bit of a left wing slant to those anthro courses I took in college;)
    otherwise, I can totally see what you’re saying. however, you might want to check out the primate studies that examine two separate populations of the same type of primate. genetically, they are the same species, but have evolved in two totally separate locations – far enough so that they could have never come into contact with one another. guess what? They had the identical culture!
    Nick Wade wrote about it in the NYT last year.

  21. dad says:

    okay, I kind of butchered that but give me a break! It was from a year and a half
    Ago…
    http://www.nytimes.com/2011/12/20/science/genes-play-major-role-in-primate-social-behavior-study-finds.html

  22. Tony says:

    Break granted. I had a look at the NY Times link. It looks like an interesting book–great, another book to read along with Razib’s Population Genetics book (which wasn’t at the library).

    A politically left-wing slant to anthropology? That sounds about as likely as a socio-biological slant to a Genetics course :)

    But all these biases can be taken in context…

  23. dad says:

    Touche:)

  24. Chuck says:

    Tony,

    “I’ll make you a deal: I’ll give you Gould to tear apart, if you’ll give me The Bell Curve!”

    I would take that deal…if by ‘tear apart’ we mean ‘logically inspect’. Generally, if you have identified anything substantially incorrect with ‘Herrnstein’s Syllogism’, which BC simply elaborated on, explain. Alternatively, if you have identified a coherent syllogism in Gould’s Mismeasure, a simple articulation of that would be nice.

    As for books, with regards to g and heritability, I would advise:

    Jensen, A. R. (1998). The g factor: The science of mental ability. Westport, CT: Praeger.

    Sesardic, N. (2005). Making sense of heritability. Cambridge University Press.
    (PDFs of these are available, for free, online.)

    “It has been a lively week on this blog. “DAD” and Razib Khan have challenged our (Michael Scroggins and myself) basic competency to discuss genetics and race/intelligence/etc.”

    I read through a couple of posts and was unable to extract your position. Generally, based on your citation of Gould, I suspect that you are currently incapable of knowledgeably discussing intelligence. Do some more reading on that topic –I’m sure that you’re a quick learner. With regards to the other topics, you seemed to have succinctly summarized your overall position in the comments:

    “But the bigger question is how much do they effect populations, and the course of history with respect to violence, etc. My answer so far: Not much. Greed and culture explain much more!”

    The problem I have with this is that I don’t see much good evidence either way. Instead, I see stances taken. Agnosticism seems to be warranted until between population studies which explicitly pit nature versus nurture (+ interaction) are conducted. Maybe we could discuss specific population differences, though?

    The original topic was violence, no? We agree that within modern populations the variance in violence explained by genes is at least modest. What makes you think that this isn’t so between populations — at least between those living in the same society? e.g., Burakumin versus non-Burakumin in Japan. I find Frost’s view, for example, plausible…

    http://evoandproud.blogspot.com/2012/12/years-end.html

  25. razib says:

    tony,

    check for these:

    Population Genetics and Microevolutionary Theory, Alan R. Templeton

    Population Genetics, Matthew Hamilton

    Genetics of Populations, Fourth Edition, Philip W. Hedrick

    Elements of Evolutionary Genetics, Brian Charlesworth and Deborah Charlesworth

  26. razib says:

    Gould isn’t respected by mainstream evolutionary biologists, for one.

    this is true. see:

    http://www.newyorker.com/archive/1999/12/13/1999_12_13_056_TNY_LIBRY_000019761

    the quote from john maynard smith is most relevant. he is indisputably one of the greatest evolutionary biologists of the 20th century

    http://en.wikipedia.org/wiki/John_Maynard_Smith

    reading *The Structure of Evolutionary Theory*, as i have, has not changed my opinion of gould….

  27. Tony says:

    @Chuck: I’m all for “logical inspection” of Gould, and The Bell Curve, side by side. But recognize that we are coming from two worlds, neither of them perfect–and both which have been hiding from each other for decades, as John Hawks points out in what I quoted on this post.

    @Chuck and Razib: I know that there is a lot of criticism of Gould. There is of Herrnstein, too. For that matter, there is of Razib Khan as well :) To a certain extent this is legitimate, but a lot of it is sound and fury as well.

    @Razib. Thanks for the references. I had a look at Hamilton on Google already, and look forward to looking at the real think when I can get a hold of it. From browsing the Table of Contents, I’m impressed that Population Genetics texts seem to lump humans and all other critters together. I’m ok with that to a certain extent, particularly when dealing with large populations, and big sweeps of history (e.g. Cavalli-Sforza). I have more of a problem with it when it comes to analyzing small local populations, and contemporary social issues.
    I did have a quick look at the Index and Bibliography, and checked for references to Weber and other sociologists who provide the foundation for social scientific understandings of race and ethnicity, Before opening my mouth (keyboard) I want to have a closer look though.

    @Razib, dad, Chuck, Michael, and Sam. This active blogging business certainly is intellectually intriguing, stimulating and fast. I’m having a tough time keeping up with it without sticking my keyboard in my mouth too many times. I don’t quite get how Razib keeps up with it year after year. I say this partly as a way to excuse myself from many of the good questions you are asking. Blogging is a good way to meet interesting engaged people, but it does not quite replace face to face conversations at the office, bar, or coffee house!

  28. Chuck says:

    “But recognize that we are coming from two worlds, neither of them perfect–and both which have been hiding from each other for decades, as John Hawks points out in what I quoted on this post.”

    Ya, I am quite aware of the many critiques coming out of sociology, the philosophy of biology, and anthropology. They typically don’t address the substantive issues though; when they do, they frequently grossly misrepresent the opposing position (e.g., Marks on race, Gould on IQ). The upshot is that there is very little to learn concerning these specific issues. In terms of overall empirical perspective, your sources don’t help either, because my perspective is inclusive of yours. For population differences, for example, my starting position is: differences equal some mix of genes plus environment plus covariance plus interaction plus error. A causal cultural perspective is incorporated.

    Generally, your world involves a constructive element, in which you create a causal narrative. You summed this narrative up when saying, “Greed and culture explain much more!” And your world involves a deconstructive element, in which you attempt to undermine what you see as the main opposing causal narrative, what you term “sociobiology.” As for that, you seem to imagine that “Sociobiology” represents a neat inverse: “Brutal Darwinian selection and genes explain much more!”

    Hmmm…

    The best place to start is to clarify what the topic is and where the disagreement lies. You state:

    “But the bigger question is how much do they effect populations, and the course of history with respect to violence, etc.”

    “Razib Khan have challenged our (Michael Scroggins and myself) basic competency to discuss genetics and race/intelligence/etc.”

    So we seem to be talking about the origin (nature/nurture) of within/between population behavioral differences. Presumably, you agree that we can disentangle the causal pathways (since you propose nurture=culture as the predominant factor)– and so you agree with the behavioral genetic framework. Do you agree with the first 2 generic “laws” of behavioral genetics, concerning within population differences: “(1) All human behavioral traits are heritable (2) The effect of being raised in the same family is smaller than the effect of genes” — or at least the first law? That is, is the disagreement about both within and between population behavioral differences or is it just about between population (understood spatially and temporally) differences?

    It’s probably better to just start with the g-factor, since Jensen deals head on which

    https://lesacreduprintemps19.files.wordpress.com/2012/11/arthur-jensen-the-g-factor-the-science-of-mental-ability.pdf

  29. Chuck says:

    Tony,

    Could you delete the last line of my most recent comment? I was going to write something to the effect of:

    “As for the IQ issue, it’s probably better, if this is a tangent we eventually wish to follow, to just start off with the g-factor, since Jensen dealt with “genetics and race/intelligence/etc” in a much less circumspect manner than did H&M (who focused primarily on class differences), since Jensen, after all, was the arch-Jensenist, and since the book is a well cited psychometric classic.”

    And I started to, but decided to omit this, weary as I am of the endless IQ debate which haunts these discussions. Thanks.

    ——-
    Did I do it right? Tony

  30. Tony says:

    In response to Chuck’s questions: “Do you agree with the first 2 generic “laws” of behavioral genetics, concerning within population differences: “(1) All human behavioral traits are heritable (2) The effect of being raised in the same family is smaller than the effect of genes” — or at least the first law? ”

    1) No, I don’t agree that all human behavioral traits are heritable. Not even that most are heritable. if they were we wouldn’t need schools, families, juvenile halls, and a whole range of other institutions to socialize our children their varied genetic backgrounds.

    2) No, I don’t agree that being raised in the same family is smaller than the effect of genes. Genes matter a a bit, particularly in the case of some heritable diseases and predispositions, but it seems to me that environment matters more. This is how we came to have a President Obama with genes from Kenya and Kansas, but who also has important social inheritances from Hawaii, Indonesia, New York City, Chicago and an anthropologist mother!

  31. Joshua Steinberg says:

    ***How do you move from the gene (pick a definition) or some sub-part of the gene to the development of an individual within a social milieu? From the unit of analysis taken by population genetics (some part of a gene) you simply cannot make assertions about complex phenomena like the display of “IQ.” ***

    @ Michael,

    Read some quantitative genetics. Steve Hsu (involved with the Beijing Genomics Institute’s Cognitve Genomics Project) discusses how you can get a 1 standard deviation in a heritable trait like IQ or height over 1000 years.

    “So we have at least two documented cases of the descendants of the rich replacing the poor over an extended period of time. My guess is that this kind of population dynamics was quite common in the past. (Today we see the opposite pattern!) Could this type of natural selection lead to changes in quantitative, heritable traits over a relatively short period of time?

    Consider the following simple model, where X is a heritable trait such as intelligence or conscientiousness or even height. Suppose that X has narrow sense heritability of one half. Divide the population into 3 groups:

    Group 1 bottom 1/6 in X; 1 SD above average

    Suppose that Group 3 has a reproductive rate which is 10% higher than Group 2, whereas Group 1 reproduces at a 10% lower rate than Group 2. A relatively weak correlation between X and material wealth could produce this effect, given the demographic data above (the rich outreproduced the poor almost 2 to 1!). Now we can calculate the change in population mean for X over a single generation. In units of SDs, the mean changes by roughly 1/6 ( .1 + .1) 1/2 or about .02 SD. (I assumed assortative mating by group.) Thus it would take roughly 50 generations, or 1k years, under such conditions for the population to experience a 1 SD shift in X.

    If you weaken the correlation between X and reproduction rate, or relax the assortative mating assumption, you get a longer timescale. But it’s certainly plausible that 10,000 years is more than enough for this kind of evolution. For example, we might expect that the advent of agriculture over such timescales changed humans significantly from their previous hunter gatherer ancestors.

    This model is overly simple, and the assumptions are speculative. Nevertheless, it addresses some deep questions about human evolution: How fast did it happen? How different are we from humans who lived a few or ten thousand years ago? Did different populations experience different selection pressures? Amazingly, we may be able to answer some of these questions in the near future.”

    http://infoproc.blogspot.co.nz/2011/08/demography-and-fast-evolution.html

  32. Tony says:

    I read the blog by Steve Hsu, and it was about the fact that over 1000 years, wealthy people tend to have more children then not-so-wealthy people. But so what? How is holding wealth carried on a gene? Wealth is a product of the social world which indeed is passed on to children via social means.

    As Hsu intimates, this relationship no longer holds–poorer people in today’s world tend to have more children then rich people. There has in fact been a demographic explosion of “poor people” over the last 300 years or so, with the ironic result is that the world’s massive middle class has also grown large, and by historical measures, extraordinarily wealthy.

    This is part of what you call the “overly simple…and speculative” that is left out of Hsu’s model!

  33. Chuck says:

    “1) No, I don’t agree that all human behavioral traits are heritable.”

    I don’t quite get your comment. Heritability estimates describe the variance in a phenotype in or between populations attributable to genes. The basic model is: Phenotype (P) = Genotype (G) + Environment (E); H^2 = Var/Var(P). Importantly, what is described is the relative influence of genes given a background population level environment. This makes your statement queer: “Not even that most are heritable. if they were we wouldn’t need schools, families, juvenile halls….'” All of the factors mentioned represent background environments. Like fluoride in the water. Generally, there is no contradiction between high heritability (i.e., high genetic influences on the variance in or between populations) and high environmental influence (in the sense of high environmental influence on a population or on populations). So, for example, given the reigning environment within developed countries/regions, most of the variance in height is attributable to genes. And it seems that a large portion of the variance between northern and southern indigenous European populations is also attributable to genes. But surely environment can have a strong influence on height! Anyways, I’m sure that Razib can explain this more clearly, see:
    http://blogs.discovermagazine.com/gnxp/2012/06/heritability-of-behavioral-traits/#.UUEDGVc4odU

    “2) No, I don’t agree that being raised in the same family is smaller than the effect of genes. Genes matter a a bit, particularly in the case of some heritable diseases and predispositions, but it seems to me that environment matters more.”

    This seems to be a basic area of misunderstanding. Read some basic intro material e.g.,

    Johnson, W., Penke, L., & Spinath, F. M. (2011). Heritability in the era of molecular genetics: Some thoughts for understanding genetic influences on behavioural traits. European Journal of Personality, 25(4), 254-266.

    ” No, I don’t agree that being raised in the same family is smaller than the effect of genes. Genes matter a a bit, particularly in the case of some heritable diseases and predispositions, but it seems to me that environment matters more. This is how we came to have a President Obama…”

    So two very apt biological parents (both top students at one time) and a broken household. And your interpretation is “shared environment.”

  34. Chuck says:

    ***How do you move from the gene (pick a definition) or some sub-part of the gene to the development of an individual within a social milieu? From the unit of analysis taken by population genetics (some part of a gene) you simply cannot make assertions about complex phenomena like the display of “IQ.” ***

    You’re confusing issues.

    Behavioral genetics concerns itself with the etiology of trait variation in a population. You can understand trait variance without understanding the developmental basis of a trait, which is an individual level phenomenon. For background, try: Tabery, J. (2007). Biometric and developmental gene-environment interactions: Looking back, moving forward. Development and psychopathology, 19(4), 961.

    Anyways, if causation is lost in developmental interaction, as you imply above, how is it that you conclude that differences are primarily cultural in origin? To conclude this, you must grant the basic biometric assumption that the cause of variance can be decomposed. You can’t have it both ways. This doublethink seems to be characteristic of contemporaneous anthropology/sociology. The whole biometric program is deeply flawed; nature can’t be disentangled from nurture; therefore nurture ueber alles!

  35. Tony says:

    @Chuck. The psychological variables in the table that Razib presents are all sampled within modern cultures, and I assume valid measures for that society. But the fact of the matter is that it breaks down when you move between societies, and/or sub-socieites.

    The nub of the disagreement we have is in your sentence above: “you must grant the basic biometric assumption that the cause of variance can be decomposed.” But variance cannot be decomposed by genes or within individuals because it is also a product of the social context. And social context cannot be decomposed into biometrics.

    I assume that we would have a great time with this in a seminar in which we were both reading some of the same articles! But sometimes in this blog format the subtleties get lost.

  36. Chuck says:

    Tony,

    Thanks for the reply.
    “But the fact of the matter is that it breaks down when you move between societies, and/or sub-socieites.”

    Cross cultural assessment is tricky. See, for example, here: Täht, K., & Must, O. (2013). Comparability of educational achievement and learning attitudes across nations. Educational Research and Evaluation, 19(1), 19-38.

    I would note, though, that it’s doable. That is, it’s possible to determine the extent to which psychometric score differences between populations are comparable to (i.e., of the same latent nature as) differences within populations. And it’s possible also to determine the extent to which differences between populations could be explained by genes (e.g., biometrically informed structural equation modeling, something like this:
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3401167/). Generally, your suspicion (about the meaning of psychometric score differences between populations) is well placed. Your skepticism about the possibility determining the meaning is not.

    “But variance cannot be decomposed by genes or within individuals because it is also a product of the social context. And social context cannot be decomposed into biometrics.”

    hmmm…”by genes or within individuals”…I don’t see why you say this. Variance within and between populations is decomposed by cause. Differences in genes, in aggregate, and environments, in aggregate, and their covariance and their interaction are modeled as causes. You would agree that genetic differences between individuals and between populations (e.g., “tall people” versus “small people”) can underlie phenotypic differences? I don’t see where the disagreement lies. You don’t think that it’s possible to determine the heritability of the height difference (i.e., the amount of difference attributable to genes) between indigenous Dutch and Southern Italians? I find that incredible.

  37. gcochran says:

    Individuals with higher values of certain traits (and for that matter lower values of certain other traits) are more likely to acquire and hold onto wealth. Genetics explains s significant fraction of the variance for every such trait. So, if the wealthy have more children than average, the genetic mix of the population changes – in the direction that tends to favor trait values that help an individual acquire and hold onto wealth.

    A human population could easily change by a standard deviation in a thousand years, due to wealth selection. Right now we’re changing faster than that: unfortunately, in the opposite direction.

    This is the basic mechanism of natural selection. Just looking at the Wikipedia article on heritability is enough to give you the gist of it.

  38. Tony says:

    @gcochran
    But in the last 1000 years (1100 a.d. to now), people have become extraordinarily more wealthy despite intervening wars, catastrophes, plagues, etc. I don’t see how genes could have changed that much in a fashion that causes “wealth.” Wealth is a product of social environment, not genetic.

  39. Josh Steinberg says:

    ***I don’t see how genes could have changed that much in a fashion that causes “wealth.”***

    No, but selection appears to have been occurring so that people with traits that lead to greater wealth had more children than those who did not.

    Another example is discussed in a recent article by Ron Unz concerning China. As Peter Frost outlines, it’s a similar model to that put forward by Greg Clark about England leading up to the Industrial Revolution:


    In this Hobbesian world, reproductive success went to those with the most business acumen:

    The members of a successful family could maintain their economic position over time only if in each generation large amounts of additional wealth were extracted from their land and their neighbors through high intelligence, sharp business sense, hard work, and great diligence. The penalty for major business miscalculations or lack of sufficient effort was either personal or reproductive extinction. (Unz, 2013)

    All of this sounds much like the model that Gregory Clark put forward to describe the demographic, behavioral and, perhaps, genetic evolution of the English people. According to this model, the English middle class expanded slowly but steadily from the 12th century onward, thereby gradually raising the population mean for predispositions to non-violence, pleasure deferment, and other future-oriented behavior. Although this social class was initially very small in medieval England, its descendants grew in number and gradually replaced the lower classes through downward mobility. By the 1800s, its lineages accounted for most of the English population (Clark, 2007).”

  40. Josh Steinberg says:

    @ Tony,

    Further to the above, you may find David C Rowe’s paper on Genetic and Shared Environmental Influences on IQ, Education, and Income.

    http://www.uam.es/personal_pdi/psicologia/pei/download/Rowe1999.pdf

  41. Tony says:

    I don’t see how a trait “business acumen” can be isolated and compared across centuries in which there were also plagues, wars, migrations, etc. Likewise, historically, urban people have had the lowest birth rates, and rural farmers (many of whom disdained business) the highest.

    There are certainly ways to explain the change in attitudes, assuming they are real, rather than genetic predispositions. I also don’t see how the “pre-disposition for violence” changed much in England between the 12th and 20th century. During this time Henry VIII, English Civil War, overseas colonialism, World Wars I and !!, the Napoleonic Wars, and a whole lot of colonial wars also occurred. Doesn’t sound too peaceful to me!

  42. Chuck says:

    “I don’t see how a trait “business acumen” can be isolated and compared across centuries…”

    Selection would likely act on a more general phenotype such as time preference which probably is moderately heritable. Time preference can be compared across species (e.g., Rosati et al. (2007), so I don’t see why not across time within a species.

    “Likewise, historically, urban people have…”

    This topic was discussed by Clark. But this is a fair example of how a relatively open minded cultural anthropology could inform sociobiology. When it comes to these models, the devil’s in the ethnographic detail.

    “I also don’t see how the “pre-disposition for violence”…”

    Different constructs: collective versus inter-individual violence. Are you even trying to?

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