Test Scores, Inequality, and “Goodnight Moon Time”

Here is a recent article about test scores from the New York Times, “No Rich Child Left Behind.”  They got through the entire article without connecting cognitive abilities to inherited intelligence.  Instead, the connection is made to wealth, poverty, and early childhood development.  Do middle/upper class things for a child at night (“Goodnight Moon time”), and they are going to fit into the academic world created by the upper and middle classes in the schools.  Goodnight Moon time in turn is highly correlated with poverty.

 

Note too that widening gaps between test scores for the upper 10% and the lowest 10% in terms of income have widened over the last 50 years. This in large part is because economic inequality has increased, and could not plausibly have to do with shifts in the gene pool of the last two generations (i.e. 50 years).

18 thoughts on “Test Scores, Inequality, and “Goodnight Moon Time”

  1. dad

    Actually assortative mating could explain a lot of it. College grads marry college grads now, used to be different.

  2. Tony

    Assortative mating is hardly new. Today College Grads marry College Grads. In the last generation, Lawyers married their secretaries, and doctors their nurses.

    Before that nobles married nobles, and peasants married peasants (except when the nobles or aristocrats raped the peasants or slaves, but that’s another story).

    My point is that in recent centuries/millenia there has been few stable mating patterns–humans have been a promiscuous lot. If this is the case, how could there be “natural selection” toward doing well on the very specific skills of the SAT, and college admissions tests?

  3. dad

    Idk there’s a growing consensus that it’s accelerated recently if you search it. Nobility didn’t necessarily have smarts but doctors do. College grads are pretty selective now compared to before.

  4. Dalliard

    Reardon’s analysis is most likely incorrect. There has probably not been any substantial rise in the association between income and test scores over the last half century. The problem is that his study uses a hodgepodge of samples that vary in their representativeness, children’s age, tests used, and reliabilities of income measures.

    A much more careful analysis of the same question was done by Christopher Jencks and colleagues. (Yes, that’s the same Jencks from Richwine’s dissertation committee.) They used data from the NAEP and NLSY studies. The samples were nationally representative, covering the periods of 1975-2004 (NAEP) and 1980-1997 (NLSY), with the same tests used throughout.

    If rising income inequality influences test scores, the dispersion of test results should increase over time. The dispersion of NAEP reading test results increased somewhat from the 1970s to 2000s, but the dispersion of math results decreased. There was no change in the dispersion of test results considered together, despite the large increase in income equality over time. This contradicts Reardon’s thesis.

    Jencks et al. also studied if income equality was associated with changes in NAEP test score gaps between the children of college grads and the children of high school grads between 1975-2004 (the income gap between college and HS grads increased over the same period). They found that the NAEP gaps between these two groups actually decreased, although the decreases were not statistically significant. They also compared the children of HS grads and dropouts, finding that from 1975 to 2004 the math and reading gaps fluctuated all over the place and had no relation to trends in the parental income gap between the two groups. They conclude that “there was no consistent relationship between the widening income gap between parents at different educational levels and the size of the gaps between their children’s reading scores and math scores.” This is another strike against Reardon.

    Jencks et al. also looked at the correlation between income and IQ (the AFQT) between two samples of (mainly) teenagers who were tested in 1979 and 1997 (the NLSY79 and NLSY97 studies). They found that despite rising income differences between parents there was no corresponding rise in test score gaps. This again contradicts Reardon’s study.

  5. Tony

    @Dailliard, good points. What do you know about the effects of early childhood socialization on outcomes? What do you think of the various studies which show that two parent homes, and focused interactions rooted in the values of the middle class schools? To a certain extent, I am thinking of the book “Unequal Childhoods” by Annette Lareau (2003).

    I like it that the focus you point to is on NAEP. This is the “gold standard” of academic testing, as these are “no stakes” tests rooted more carefully in the principles of sampling, rather than a push to evaluate students and teachers. Certainly they are much better than citing SAT scores like Reardon does in the NY Times article. As I pointed out in my post about “Campbell’s Law,” such tests are at least in my mind, corrupted when it comes to making comparisons across time, and places. The NAEP is much better.

    How do we explain though the difference in college graduation rates based on class? Or maybe this is not a problem? The push of the middle and upper classes toward college, and the lower and working classes toward retail, terminal programs at Community Colleges, and the military is still very real.

  6. Tony

    Here’s another link critiquing the IQ and Race issue, this time as discussed by Andrew Sullivan. http://studentactivism.net/2013/05/14/9482/#comment-84676

    I’m of course sympathetic to many of the points raised here, but perhaps someone like dad or dailliard could quickly critique it from another perspective.

  7. Dalliard

    “What do you know about the effects of early childhood socialization on outcomes? What do you think of the various studies which show that two parent homes, and focused interactions rooted in the values of the middle class schools?”

    Using behavioral genetic (BG) methods, it can be shown that the shared family environment has little lasting influence on individual differences in traits like IQ. There’s substantial influence in childhood, especially early childhood, but as the children grow up, their differences will be almost entirely determined by genetic influences and idiosyncratic environmental influences that are not shared between members of the same family.

    For example, here are the estimated effects of genetic and environmental components on IQ at different ages, based on twin studies: http://tinyurl.com/bx4tdas Most data suggest that the effect of shared childhood environment on IQ (and many other traits, such as the Big Five personality) is close to zero in adulthood, and even those researchers who insist that it is higher admit that it can be at most 20 percent. Hidebound socialization theorists have unfortunately yet to absorb this fact. That family socialization has traditionally been greatly exaggerated is easy to see from the fact siblings are often very different from each other. For example, the expected IQ difference between a random pair of individuals from the same population is 17 points. The expected IQ difference between siblings (excluding MZ twins) is nowhere near zero: it is about 12 points. Between adoptive siblings (i.e., those raised together who are not genetically related) the difference is about 17 points, the same as between random individuals. Most IQ variation exists within families, not between them. Within families, siblings are similar because they share genes, not because of the shared environment.

    Lareau’s book is a good example of misguided thinking about family socialization. Her methods are completely unsuitable for the task at hand, because everything she studies is confounded by genetic effects. Without a BG study design, she cannot make any valid causal interpretations. Note that BG methods are not only about studying genetic effects. They also represent the best methods for studying the effects of the environment, because they can be used to separate genetic from environmental effects and the shared from the non-shared environment. This excellent Amazon review well captures my perspective on Lareau: http://tinyurl.com/b8j355c With respect to race, the reviewer brings up the robust but little appreciated fact that blacks from college educated, well-to-do families have similar (or lower) IQs as whites from poorly educated, working class families. This is difficult to plausibly explain in terms of shared family influences, or indeed any non-genetic effects.

    Judith Rich Harris’s The Nurture Assumption is a good introduction to BG.

    “As I pointed out in my post about ‘Campbell’s Law,’ such tests are at least in my mind, corrupted when it comes to making comparisons across time, and places. The NAEP is much better.”

    The SAT has an advantage over the NAEP in that students have an incentive to do well on it. With the NAEP that’s generally not the case. Whether Campbell’s law has corrupted the SAT is something that cannot be decided a priori. It’s an empirical question. As I pointed out earlier, the validation data show that the SAT is not corrupted. The correlation between the SAT and the ASVAB IQ battery is more than 0.80, which is similar to the correlation between two typical IQ tests.

    “How do we explain though the difference in college graduation rates based on class? Or maybe this is not a problem? The push of the middle and upper classes toward college, and the lower and working classes toward retail, terminal programs at Community Colleges, and the military is still very real.”

    To a considerable extent it’s just about genetic differences between social classes, and not a problem. However, I certainly agree that kids from lower class backgrounds are at a disadvantage when it comes to higher education. America’s elites are so obsessed with addressing racial disparities that little attention is paid to class disparities. There are plenty of smart kids from the wrong side of the tracks who underperform relative to their academic potential. However, these kids are generally whites from the “flyover country”, so they don’t have a constituency (see Hoxby and Avery’s NBER Working Paper No. 18586 on high-ability low-SES students).

  8. Dalliard

    “Here’s another link critiquing the IQ and Race issue, this time as discussed by Andrew Sullivan.”

    His argument is so weak and hackneyed that it’s difficult to muster up the energy to refute it, but here goes:

    – In America, racial categories are strongly grounded in biology. As noted in the first comment over there, the correspondence between genetic clusters and racial/ethnic self-identification is almost perfect.

    – To the extent that admixture blurs racial categories, whatever relation there is between genetic ancestry and variables of interest (such as IQ) is attenuated. Using DNA rather than self-identification to identify races makes the associations, if any, between ancestry and phenotypes stronger, as can be seen in many biomedical studies. (Indeed, genomic admixture studies could be used to solve the riddle of race and IQ to everyone’s satisfaction, but such studies aren’t being done for ideological reasons.)

    – IQ or general mental ability is one of the best validated constructs in the social sciences. If he wants to claim that IQ is a poor measure of intelligence, he must first define and operationalize intelligence and then show that IQ is poorly correlated with it.

    – His claim that “Folks have been searching for evidence of heritable intellectual differences between ethnic populations for a very long time, and they’ve pretty much come up empty” fits non-hereditarian theories of race and IQ much better. There is plenty of evidence that the black-white gap in particular is largely genetic. In contrast, researchers who maintain that the gap is caused by environmental disparities openly admit that they cannot pinpoint any environmental factors that could explain the gap. This despite the fact that non-hereditarian approaches to the question have received several orders of magnitude more funding.

    – His argument that nothing good would be gained from knowing that racial IQ gaps have a genetic basis is without merit. He is just defending the status quo. I don’t think anything good has ever come from attempts to suppress scientific inquiry. For example, I don’t think that eternally scapegoating one race for the failings of another is conducive to interracial harmony.

    – His claim that “nobody” argues that humans have not evolved since the emergence of the species is false. For example, Stephen Jay Gould argued just that. Much of evolutionary psychology is also based on this false idea.

  9. Tony

    @Dailliard: Well that was certainly a long involved response! I appreciate the effort, but I still think that our basic assumptions are the problem. As I mentioned on another post, one of the things I agree with Andrew Sullivan on is his definition of IQ:

    “I believe IQ is an artificial construct created to predict how well a random person is likely to do in an advanced post-industrial society. And that’s all it is. It certainly shouldn’t be conflated with some Platonic idea of “intelligence.””

    Both the SAT and the Armed Forces tests are measures of this–thus they would be expected to have a pretty high correlation. THis is particularly

    I just can’t figure out how my great-great grandparents (born about 1850 in a pre-industrial society) could have done as well on a fill-in-the-bubble test as my kids (born 1990). On the other hand, I’m pretty sure that my kids would have been pretty lousy at the farm chores that my great-great grandparents did.

    The same question could be asked of the students of Shanghai who are really good at fill-in-the bubble standardized tests–which indeed do reflect their capacity to do well at post-industrial society. But their grandparents–the ones who survived the Culture Revolution and the previous 100 years of war and revolution–were selected for their farming skills.

    I agree with you that humans have evolved genetically and culturally, and continue to do so. But I just don’t get how this could occur quickly enough to justify differences in i.q. scores. I think a much more straightforward explanation is found in the different types of socialization Annette Lareau describes with respect to social class (not race).

  10. Michael Scroggins

    @ Dalliard

    “- In America, racial categories are strongly grounded in biology. As noted in the first comment over there, the correspondence between genetic clusters and racial/ethnic self-identification is almost perfect.”

    Clustering is not a value-free act. As Gravlee (2009) has noted, clustering can be done in many different ways and is neither value-free nor prior to assumption. It proves nothing except that computerized tools carry implicit assumption, which researchers using them for analysis should take into account.

    “- IQ or general mental ability is one of the best validated constructs in the social sciences. If he wants to claim that IQ is a poor measure of intelligence, he must first define and operationalize intelligence and then show that IQ is poorly correlated with it.”

    Again, IQ tests have been demonstrated time and again to lack ecological validity. They measure something; that much is a given. However, what they measure has very little to do with what they claim to measure and everything to do with social status. All thought is concrete and engaged in the particulars of the situation in which it occurs. The g-factor lacks ecological validity precisely because thinking in abstractions is a glass bead game in which the style of thought, not the substance of thought is important.

    There is a pretty good example of the style of thought problem: http://www.salon.com/2013/05/20/sats_right_answers_are_all_wrong_partner/

  11. Tony

    I like the illustration on the Salon Article. My publisher adapted the same photo for the cover of my book, “Schooling, Childhood, and Bureaucracy..”

    http://www.amazon.com/Schooling-Childhood-Bureaucracy-Bureaucratizing-Child/dp/1137269715/ref=sr_1_1?ie=UTF8&qid=1369157461&sr=8-1&keywords=Bureaucratizing+the+Child

  12. Dalliard

    “I just can’t figure out how my great-great grandparents (born about 1850 in a pre-industrial society) could have done as well on a fill-in-the-bubble test as my kids (born 1990).”

    If you could give the same IQ test to your great-great grandparents and your kids, the latter would almost certainly do much better on it. But this would not prove that your kids are smarter than their ancestors. To a considerable degree, IQ scores reflect an individual’s ability to acquire the sorts of cognitive skills needed in a particular society. However, while the contents of a particular IQ test may be culturally contingent, the ability to perform well on it depends on culturally invariant neurophysiological differences, as shown by the fact that IQ is highly heritable and linked to many other biological variables.

    Take a look at my comments to the post “The Political Economy of IQ, Or Tilting At Windmills with Steve Hsu (and Jason Richwine)”, where I explain the difference between intelligence tests and the constructs that they are designed to measure.

    Whether some test measures the same construct across different groups (such as different races or different age cohorts) is an empirical question that can be answered using established methods (such as analysis of measurement invariance). IQ tests are generally not valid for between-generation comparisons, so the Flynn effect does not indicate that intelligence is increasing. There’s even some evidence to the contrary, with a recent study suggesting that the Victorians of Francis Galton’s time had faster reaction times than today’s Europeans and Americans (reaction time being an arguably culturally neutral indicator of general intelligence).

    “I agree with you that humans have evolved genetically and culturally, and continue to do so. But I just don’t get how this could occur quickly enough to justify differences in i.q. scores.”

    One of the great myths of popular and semi-scholarly discussions on these topics is the idea that an extremely long time is needed for natural selection to produce population differences in quantitative traits like IQ. This is not the case at all. Mathematically, the response to selection, R, is simply the product of narrow-sense heritability h^2 and the selection differential S (which is the difference between the mean of the individuals that reproduce and the mean of the population), or R=h^2*S (AKA the breeder’s equation). Thus, if we assume that the narrow-sense heritability of IQ is 0.50 and there’s extreme selection on IQ so that the average IQ of parents is 2 SDs above the mean (IQ 130), then the expected mean of the children is 100+0.5*(130-100)=115. Selection in one generation is unlikely to ever be as extreme as this outside of animal and plant breeding, but a small positive selection differential over many generations will produce the same effect. See this example by Henry Harpending showing how the great decline in violence in Europe over the last 700 or 800 years could easily have been due to the most (genetically) homicidal 1.5% of the European population failing to reproduce over each of the last 28 generations: http://westhunt.wordpress.com/2012/11/25/genetics-and-the-historical-decline-of-violence/ He’s not saying that this is what actually happened, but the point is that those who insist that meaningful natural selection takes aeons are simply ignorant of basic quantitative genetics.

    “I think a much more straightforward explanation is found in the different types of socialization Annette Lareau describes with respect to social class (not race).”

    You may think so, but the data contradict you.

  13. Dalliard

    “Clustering is not a value-free act. As Gravlee (2009) has noted, clustering can be done in many different ways and is neither value-free nor prior to assumption. It proves nothing except that computerized tools carry implicit assumption, which researchers using them for analysis should take into account.”

    Look at the first graph in the post by Razib Khan that you criticized earlier. It represents a PCA of genetic variation. PCA is a model-free procedure, so the clear racial patterns in the graph (i.e., PC1 separates whites from Africans, PC2 separates African agriculturalists from hunter-gatherers) are something that emerge from the data. They’re not something that the researchers assumed would be found. The patterns are what they are because allele frequencies follow the ancestral geography of the populations studied as a result of selection, drift, and other ordinary processes of evolution. The only assumption in this analysis is that race differences can be thought of as an additive function of SNP differences, but any other assumption would be difficult to justify (and would not produce different results anyway).

    Now, dividing people into races is not the only way to split up human genetic variation. For example, you could also divide the children of white middle class Americans into dumb and smart ones, and there would be systematic genetic differences between these two groups. However, the failures of dumb middle class whites are not considered a social problem, and thus this category of people is not salient in social science or public discourse (for an analysis of outcome differences between dumb and smart siblings from well-to-do families, see Charles Murray’s article in The American Economic Review, 92, pp. 339-343). In contrast, race is a highly salient social fact in America and elsewhere, and one that is constantly used as an explanatory variable in social theory and political rhetoric, so it’s intellectually dishonest to rule out a priori the influence of genetics on racial differences.

    “Again, IQ tests have been demonstrated time and again to lack ecological validity.”

    No they haven’t. You keep repeating that assertion without offering a shred of evidence for it.

    “There is a pretty good example of the style of thought problem: [Salon link]”

    It is a common fallacy to think that you can decide whether a test item makes sense or is biased in favor or against some group simply by verbally analyzing it. Cohen fails to say anything interesting about that item because she does not present the item statistics, i.e., statistics on how the item works for students of different ability levels and backgrounds. The SAT is a carefully validated test, so we can be confident that the item statistics are good.

    A good example of the fallacy that the “face validity” of test items can be used to detect bias comes from a classic study by Frank McGurk. He had a panel of 78 judges (who were mostly social science professors and graduate students, educators, and counseling and guidance professionals) analyze a large number of IQ test items for cultural bias against African Americans. He then selected 74 items that were rated either “least cultural” or “most cultural” by the panel, and administered them to a sample of black and white students. The students were matched so that each black student was compared to a same-age white peer who had the same parental SES (as measured by a detailed 11-item index) and who was enrolled in the same school and had the same curriculum. The expectation was that the more “culture-loaded” the item was, the larger the gap between blacks and whites on it would be. However, on the 37 items classified as “most cultural”, the white advantage was 0.30 SD, while on the 37 items classified as “least cultural”, the gap was almost twice that, 0.58 SD. The “cultural bias” explanation of the black-white test score gap is simply false. As Arthur Jensen showed in many studies, the magnitude of the gap has very little to do with specific test contents and very much to do with the cognitive complexity of the tests used, as indexed by their g loadings.

    You may think that you can judge what a test item measures and whether it is biased just by looking at it, but the research shows that no, you cannot do that. So don’t do it.

  14. Michael Scroggins

    @ Dalliard

    If PCA were “model-free” as you claim, then all results from PCA would be consistent. But, as Gravlee correctly points out, neither the number of clusters nor the boundaries of those clusters are consistent. They vary. The feeling that you can escape your assumptions is an act of pure fantasy. Stridently proclaiming that you have escaped your assumptions is an act of pure hubris. Neither has the first thing to do with science.

    What our exchange in the other thread over ecological validity indicated is that you don’t have the vaguest idea about what it is, or why you should pay attention to it. Considering your attitude towards clustering, this isn’t surprising.

    The point of the Salon article is that an adequate answer about a narrator’s attitude in a complex piece of literature cannot be captured by a single word answer. It isn’t about one answer being better than another answer. It is about any answer of that form being ridiculously inadequate.

    One might say the SAT literature question lacks ecological validity. If you understood the concept, then you would understand why your response to the article is absurd. But, you show no interest in anything that might challenge your assumptions. In this regard you follow McGurk, Jensen and Murray with great fidelity.

  15. Tony

    @Dalliard:
    I don’t quite understand your hostility to the data Annette Lareau collected. Her data was collected in the tradition of Pierre Bourdieu, who described how “habitus” (i.e. culture) is used to reproduce pre-existing of systems of inequality using the social and cultural capital accumulated through the schooling systems (including tests like the SAT). This approach is also consistent with Andrew Sullivan’s definition of what IQ tests measure being rooted in the values of post-industrial society.

    If I am to take your data seriously, you need to take Annette Lareau seriously, too.

    Tony

  16. Dalliard

    “If I am to take your data seriously, you need to take Annette Lareau seriously, too.”

    Lareau’s problem is that she confuses correlation and causation. Everything she studies is confounded by genetic effects, so her conclusions are unsupported. Research on the effects of family socialization that disregards the basic findings of behavioral genetics is causally uninterpretable. These findings are handily summarized in Turkheimer’s three laws of behavioral genetics:

    * First Law. All human behavioral traits are heritable.

    * Second Law. The effect of being raised in the same family is smaller than the effect of genes.

    * Third Law. A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families.

    Lest you think that this represents some sort of extremist thinking, I’ll note that Eric Turkheimer is firmly in the “nurturist” wing of behavioral genetics, and is always stressing the importance of environmental factors even when his colleagues are skeptical. So the three laws are a very moderate interpretation of the body of BG research.

    It’s strange how behavioral genetics which constitutes perhaps the most advanced body of theory, methodology, and empirics in social science is pitted against Lareau’s methodological primitivism. Causal inference in social science is extremely hard, and behavioral geneticists have spent an enormous amount of theoretical and empirical energy on disentangling correlation and causation. In contrast, Lareau’s methods offer no way to separate causes from effects. Why am I supposed to take her causal interpretations, which are contradicted by tons of evidence, at face value?

  17. Dalliard

    “If PCA were ‘model-free’ as you claim, then all results from PCA would be consistent. But, as Gravlee correctly points out, neither the number of clusters nor the boundaries of those clusters are consistent.”

    Results from PCA are consistent if the data used are consistent. For example, if your data comprise only Europeans and sub-Saharan Africans, PCA will always separate them cleanly, i.e., there will be very clear clusters along continental lines. However, let’s say you include in your analysis also people who are genetically intermediate to Europeans and sub-Saharans, such as Northern and Saharan Africans (who fall along a cline between Europe and SS Africa) or African Americans (who are mostly SS African but have varying degrees of European admixture). In a PCA, these intermediate populations will form a “bridge” between Europeans and SS Africans, perhaps precluding meaningful clustering. But this does not mean that genetic differences between Europeans and SS Africans are any less than what the original analysis indicated!

    Whether human genetic variation is entirely clinal or whether there’s also clustering is immaterial with respect to questions such as the etiology of race and IQ differences in America. If there are genetic differences between two populations, then the possibility that heritable differences influence behavioral differences between them logically follows. For example, no one thinks that, say, dumb and smart (ethnic) Norwegians belong to different biological taxa, but dumb and smart Norwegians still differ genetically from each other. Taxonomy is a red herring in discussions of the possible genetic underpinnings of race differences in behavior.

    As shown in many studies, in America socially identified races in fact fall nicely into clusters that correspond to the races of traditional anthropology. This is because while global genetic variation is highly clinal, Americans are not randomly sampled from all corners of the world. Rather, the sources of ancestry of Americans are still highly biased towards a few geographically separated locations (Europe, West Africa, the Americas, East Asia in particular). Regardless of how continuous human genetic variation is on a global scale, Americans cluster by continental ancestry because their ancestors came disproportionately from a few widely separated locations along that continuum. As I explained above, such clustering is not necessary for there to be heritable differences between groups, but it does increase the likelihood that there are such differences.

    “What our exchange in the other thread over ecological validity indicated is that you don’t have the vaguest idea about what it is, or why you should pay attention to it. Considering your attitude towards clustering, this isn’t surprising.”

    My impression here is that it is you who don’t know what ecological validity is. To prove me wrong, stop making empty assertions and instead demonstrate, using well-replicated, psychometrically sound research findings, that you’re not full of it.

    “The point of the Salon article is that an adequate answer about a narrator’s attitude in a complex piece of literature cannot be captured by a single word answer. It isn’t about one answer being better than another answer. It is about any answer of that form being ridiculously inadequate.”

    There’s no evidence for that. All that is needed for a test item to “work” is that it correlates, however weakly, with the underlying ability that is being measured. It is a given in psychometrics that all measurement is noisy and contains error. Any one item is a poor indicator of the ability of interest, but a number of items together provide a reliable measure because the reliable variance cumulates into the composite score.

    Cohen took one SAT item, did a superficial exegesis of it, and extrapolated her interpretation into a wide-ranging theory of tests and education. No step in her chain of reasoning is supported by anything other than her own half-assed intuitions. It’s not a scientific argument. Even if she was right in her “face validity” analysis of that item (and we know that such analyses are highly unreliable), it would mean little because one item accounts only for a tiny fraction of the variation in SAT scores. The SAT is a very good predictor of scientific, technological, and literary creativity, as shown by the longitudinal SMPY study where kids who scored highly on the SAT in early adolescence have been followed through adulthood. The contrast Cohen makes between “the play of ideas and the depth of thought” and IQ-type tests is a mirage. Both require the same abilities.

  18. Tony

    @Dailliard’s. I’m not convinced by Turkheimer’s three laws, but I have not read enough about it to give a comprehensive response. But I am skeptical of any law that beings “All human behavioral traits are heritable…” But Like I said, I have not read enough to analyze it. I did have a look at the leading molecular genetics journals Tables of Contents, and can see that it is an established field, albeit one with different basic assumptions than the social sciences. Thus I think our differences in opinion about works that assume more of a broader “blank slate” approach to culture and inheritance.

    I have an article coming out in a few months which explains the assumptions about this approach more generally, and will post about it here when it becomes available, hopefully later this year. I will be interested to get your reaction.

Comments are closed.