The Unz Review - Mobile
A Collection of Interesting, Important, and Controversial Perspectives Largely Excluded from the American Mainstream Media
Email This Page to Someone

 Remember My Information

 Teasers[email protected] Blogview

Bookmark Toggle AllToCAdd to LibraryRemove from Library • BShow CommentNext New CommentNext New ReplyRead More
ReplyAgree/Disagree/Etc. More... This Commenter This Thread Hide Thread Display All Comments
These buttons register your public Agreement, Disagreement, Troll, or LOL with the selected comment. They are ONLY available to recent, frequent commenters who have saved their Name+Email using the 'Remember My Information' checkbox, and may also ONLY be used once per hour.
Ignore Commenter Follow Commenter
🔊 Listen RSS

It’s nice to see a bad idea demolished. And that’s what Greven, et al. do in “More than just IQ.” Their subtitle tells most of the story:

School achievement is predicted by self-perceived abilities (SPAs)–but for genetic rather than environmental reasons.

So asking kids “Are you good at math and English?” is indeed a good way to find out who is good at math and English; and basic twin-study methods show that the answers to those questions are in fact genetically-driven, with heritability of 51% and family environment explaining 2%.

Another family environment channel shot down. The authors drive that fact home:

Despite the fact that not a single twin or adoption study has investigated the genetic and environmental etiologies of SPAs, researchers have cited environmental factors as a leading causal explanation for constructs related to SPAs, such as self-efficacy…and self-concept….. Moreover, one of the most established theories of SPAs assumes that the development of individual differences in SPAs is shaped primarily by parents’ beliefs, expectations, attitudes, and behaviors…

Of course, the bulk of the academic literature will surely go right on assuming that self-construct is driven by shared environment: “Surely, you don’t mean to imply that an entire field of research was a waste of time, do you?” And in the policy and non-profit worlds these results won’t stop those “Book in Every Home” campaigns. Alas….

More results:

The genetic component of self-perceived abilities (SPA) is a good predictor of achivement, after you control for IQ.

Even after you control for IQ and self-perceived ability, there’s still a big genetic residual–about as big as IQ’s genetic channel: So there are big genetic drivers of school achievement that don’t fit into the two simple boxes of IQ and SPA. Sounds like an opportunity for some productive data-mining….

The big genetic residual fits in with the fact that a person’s income is vastly more heritable than can be explained by the IQ channel alone. There are more things in gene expression, Horatio, than are dreamt of in your WAIS-R.

• Category: Science • Tags: Behavior Genetics, Education 
🔊 Listen RSS

Anti-Irish caricatures, the hypothesis that some races contain little intra-race variation, and how economists keep arguing–normatively and positively–for the rough equality of humankind: It’s all in Peart and Levy’s book The Vanity of the Philosopher.

The book is highly recommended to GNXPers with any interest in the complicated historical relationship between genetics and social science. The major value-added comes from the oft-ignored tension between economic theorists and evolutionary theorists. Well, that and the cartoons.

The book builds on Levy’s earlier work How the Dismal Science Got its Name. A free, abbreviated version of that story is here, and is wiki’d here.

For some HBD newbies, the best part of Vanity will be the discussion of the Irish: In the early days of Darwinism, the people of the Emerald Isle were Exhibit A (or B) of an inferior race. Peart and Levy have a great discussion of how 19th century intellectuals hoped the Irish to evolve to become as well-mannered as, say, the English. And in the 19th century, whenever attacks on the Irish started up, attacks on abstract, unrealistic, ahistorical economic theory were rarely far behind. Funny, that…

Oh, one more reason to take a look at Vanity: Peart and Levy slide the knife into Charles Dickens, a sight always to be relished.

• Category: Economics, Science • Tags: Economics 
🔊 Listen RSS

Or is it more like “letting sleeping dogs lie?”

On the issue of that new statue:

That Proto-German sex toy is fun enough, but it’s time the media stopped elevating things like it as evidence that our species only learned to think abstractly among its subset who, if the lifespan of our species were 24 hours, happened to wander into Europe around 7 PM.

Full article here (including swipes at Steve).

• Category: Science 
🔊 Listen RSS

The surnames of the criminal and the poor, of course. Greg Clark provides new evidence for the “survival of the richest” here (and he thanks Nick Wade for the idea). From the abstract:

[E]vidence from…surnames…again shows the takeover of English society by the economically successful between 1600 and 1851, and the disappearance of the criminal and the poor. A man’s economic success in pre-industrial England predicted a permanent increase of his surname frequency, and hence his gene frequency, by 1851.

Confession: I, for one, had no idea that Elvis was a surname.

Clark’s papers have familiarized economists with the basics of genetics. It seems to be paying off: At the American Economic Association meetings this year, there was a session on brain evolution in the very long run, another on genetics and microeconomic behavior, and a third GNXP-friendly session where Clark presented the above-quoted paper.

• Category: Science 
🔊 Listen RSS

That’s the result from a new experimental study of 1,000 people attending truck driving school. The authors tested all of them with Raven’s Progressive Matrices, a real IQ test. They then put pairs of them through a prisoner’s dilemma game, and found:

[M]easures of cognitive skill [CS] predict social awareness and choices in a sequential Prisoner’s Dilemma game. Subjects with higher CS’s more accurately forecast others’ behavior….[S]ubjects with higher CS’s also cooperate more as first movers.

This set of genuine experiments improves on this older paper, which found that students at high-SAT schools cooperated more in prisoner’s dilemmas than students at low-SAT schools. Now we know it’s not just because posh, high-SAT schools facilitate a “culture of cooperation” or something like that. Smart individuals just figure it out on their own…..

Bottom line: More evidence that smarter groups are more likely to think win-win.

• Category: Science • Tags: IQ 
🔊 Listen RSS

Economists are getting into the twin-study game more often. The latest entry is forthcoming in the Harvard-MIT run Quarterly Journal of Economics. They ran tests on a bunch of Swedish twins, tests that involved real money. The goal: See how altruistic they were (how much money did they share with a pro-homeless charity?) and see how risk-tolerant they were (how big does the reward have to be before they’d take a risky gamble?).

Key quote:

[W]e have used standard behavior genetic techniques to decompose variation in preferences for giving and risk-taking into environmental and genetic components. We document a significant genetic effect on risk taking and giving, with genes explaining approximately 20% of phenotypic variation in the best fitting models. The estimated effect of common environment, by contrast, is smaller.

So E>A>C, a common result. Since economists have spent a fair amount of time arguing for the social construction of preferences, it’s good to have some evidence that shared family environment–presumably one important kind of “social construction”–apparently has only a modest association with routine economic preferences.

Note: This is the same group of researchers that found that 40% of “responder” behavior in an ultimatum game was heritable.

Conclusions: 1. The Swedish Twin Registry is a treasure. 2. Responder behavior (basically, willingness to punish even when it’s expensive to punish) seems about twice as heritable as risk-taking and altruism. We’re only going on two studies here, but that’s an interesting result: Perhaps “Desire for justice/revenge” is more heritable than “Fear of loss” and “Kindness.”

• Category: Science • Tags: Behavior Genetics 
🔊 Listen RSS

The first correct daily temperature forecast was not broadcast [in China] until July 1999. Previously, temperature predictions were never permitted to fall outside the range for efficient factory work.

That’s from Cultures Merging: A Historical and Economic Critique of Culture, by Eric Jones. Jones is best known for his book The European Miracle, an anti-Pomeranz text if there ever was one. In Cultures Merging, he provides decent anecdotal evidence that while “bad culture” might be able to hold back a country back a little, cultures are actually fairly fluid over the span of decades, and tend to steer in the direction of economic efficiency (a point emphasized by Clark). Jones’s pet example is East Asia, where Confucianism was once said to be a barrier to economic development (too much blind obedience to the dead hand of hierarchy) but is now lauded as the driving force behind superior “Asian Values” of hard work and sacrifice.

The first half of the book (parts one and two of four total) can be easily recommended to those interested in the culture question. Lots of stories, some big-think, some bold generalizations. The second half is filled with stories about his Asian graduate students; not sure what that’s all about.

But while it’s fun to read books about culture, it sure would be nice to bring some rigor to the debate, wouldn’t it? My preference–typical for an economist–is to look for the key under the lamppost of things we can actually measure. Lynn and Vanhanen’s national average IQ measures spring to mind–and boy are those scores ever robust as predictors of national economic outcomes. And Jones and Schneider show that even if you control for “cultural” variables like Confucianism, Islam, or Buddhism, the nation’s average IQ is still a strong predictor of economic performance. High-IQ groups are likely to have some good cultural traits like patience, cooperativeness, and a tendency to agree with economists on the merits of untrammeled competition.

What’d be nice to know at this point is “What’s left after you control for national average IQ?” Do cultural variables (as measured in, say, the World Values Survey) still have predictive power? It might be all stems and seeds, but right now we don’t know. Sure would be nice if someone out there did some research into this….

• Category: Economics, Science • Tags: Culture, Economics 
🔊 Listen RSS

Debin Ma of the London School of Economics has spent time in the archives and has come to conclusions quite different from Pomeranz’s.

Ma’s recent papers (especially this one and this one) make archive-driven comparisons of European and East Asian living standards around the start of the industrial revolution. Both papers have coauthors, but I focus on Ma because he speaks and reads both Japanese and Chinese, something lamentably rare among economic historians at English-speaking universities.

One quote from the abstract of the first-linked paper:

Matching caloric and protein contents in our Japanese consumption baskets with those in European baskets, we compare Japanese and European urban real wages. Real wage rates in Kyoto and later Tokyo are about a third London wages but comparable to wages in major Southern and Central European cities for the 1700-1900 [period].

From the abstract of the second-linked paper:

In the eighteenth century, the real income of building workers in Asia was similar to that of workers in the backward parts of Europe and far behind that of workers in the leading economies in northwestern Europe. Industrialization led to rising real wages in Europe and Japan. Real wages declined in China in the eighteenth and early nineteenth centuries….

A lot of Ma’s work is Japan v. China, not Asia v. Europe, so both lines of his agenda are likely of interest to GNXP readers. Given the overfishing in the pool of English-language economic history documents, Ma should be able to just throw his net overboard and pull in the big hauls for at least another decade.

• Category: Economics, History, Science • Tags: Economics, History 
🔊 Listen RSS

Svante Paabo’s group just finished sequencing the complete mitochondrial DNA of a Neanderthal. The article is in the newest Cell. John Hawks has a summary.

One of the big findings: In one tiny way, we’ve become more like monkeys recently, since Neanderthals, chimps, and other sequenced apes have the same non-homo-sapiens variants on COX2, but these human variants are common among old world monkeys. Guess I’ll have to take my pet macaque off of Vioxx now.

Upshot: Something big may have happened to human metabolism in the last few hundred thousand years since our split from the Neanderthals. And on this one gene, the solution our species found looks like the same solution that works for monkeys.

• Category: Science 
🔊 Listen RSS

Daniel Koretz of Harvard’s Graduate School of Education took the lecture notes from his course, “Methods of Educational Measurement,” and turned it into a book: Measuring Up: What Educational Testing Really Tells Us. It’s readable, filled with funny anecdotes, and contains absolutely nothing that will be new to regular GNXP readers.

But because Koretz takes the math and most of the controversy out of the debate over standardized tests, he has time to actually drill home a couple of important points repeatedly: Modern standardized tests have little bias, are pretty reliable, and while they don’t tell you everything about a person or a school or a city, they are good for making rough predictions.

Hence, the title of this blog post: Feel free to recommend Measuring Up as a “baby steps” book for your favorite sociologist or folk guitarist.

Koretz waves his political correctness card early on, letting us know that “IQ [is] just one type of score on one type of standardized test…” and he lets us know about the “pernicious and unfounded view that differences in test scores between racial and ethnic groups are biologically determined.” But you already knew he was going to say that, right? And in an unintended parody of blank-slatism, he has a chapter entitled “What influences test scores” that never once mentions genetic factors, even to dismiss them.

Koretz does a great job dodging such troubling questions while focusing on what he really wants to talk about, with solid, candid chapters entitled “Validity,” “Inflated Test Scores,” “Error and Reliability,” chapters that actually do a good job of conveying big ideas about non-experimental social science in jargon-free prose. Kudos to him for doing so.

Treat it as a book on the narrow field of psychometrics and its link to policy, not as a book on the broader field of standardized tests per se and its link to policy: You’ll spend a lot less time grinding your teeth.

• Category: Science • Tags: Psychology 
🔊 Listen RSS

Tabarrok nails it.

Agnostic adds: Here’s a graph using the new study’s finding of same mean for males and females, and taking male to female ratio in variances to be 1.16 (they estimate it between 1.11 and 1.21). This is the ratio of a normal with mean = 0 and s.d. = 1.077 (male) to a standard normal (female). It’s shown for above-average people, but it’s symmetric about 0: males have more geniuses and more idiots. The dashed green line is M:F = 1, or perfect gender parity. Males are underrepresented between -1 and +1 s.d., and overrepresented outside this interval. You may have to click on the image to see it full-size.

• Category: Science • Tags: Sex Differences 
🔊 Listen RSS

Gintis and Bowles have done great work cleaning up a lot of the discussion about cooperation, evolution, and economic outcomes. A Google Scholaring of their names turns up 14 items with over 100 citations, most of which would be well worth reading for GNXP regulars.

But that said, in their 2002 Journal of Economic Perspectives piece “The Inheritance of Inequality,” they appear to make a small error. It’s an error that’s all-too-easy for even good folks to make: They apparently squared the h-squared.

Their big insight and their small error are all part of answering a simple question: How much of the correlation of income between parent and child can be explained by the heritability of IQ? You might think it’s straightforward: IQ is highly heritable, so if there’s some channel linking IQ to income, then it’s all over but the shouting.

But numbers matter. And Gintis/Bowles work out the numbers, finding that there’s a weak link in that causal chain: The low correlation (0.27 according to Gintis and Bowles) between IQ and wages. The causal chain goes like this:

1. Parental earnings have a 0.27 correlation with parent’s IQ.
2. Heritability of IQ between parent and child is a bit more than 1/2 of h-squared (why a bit more? assortive mating). They take an h-squared of 0.5 for IQ.
3. Child’s earnings have a 0.27 correlation with child’s IQ.

So the net result is 0.27*0.3*0.27 = 0.022 (page 10). A very small number, especially since the raw parent-child income correlation in U.S. data is about 0.4. So yes, knowing a parent’s income helps you predict their adult (especially male) child’s income. But only 5% (or 0.022/0.4) of the total correlation can be explained by IQ’s impact on wages. Small potatoes.

(Oh, but where’s the small error? It’s where Gintis and Bowles report that the net result is 0.01 instead of 0.022–a difference that I can most easily attribute to a mistaken squaring of the h-squared.)

If I really wanted to get that net result up from a measly 5%–if I knew in my heart that IQ really was a driving force in intergenerational income inequality–then how would I do it? Well, I might use a higher heritability of IQ, I might assume more assortive mating, or I might assume a bigger correlation between wages and IQ.

Hard to do much to budge that IQ/wage link: Zax and Rees’s paper only has a 0.3 correlation between teenage IQ and middle-aged wages, and when Cawley, Heckman et al. regress NLSY wages on the first 10 principal components of the AFQT, they get a similar result.

So you think maybe a higher heritability of IQ will save you? Well, let’s just go all the way to perfect heritability of IQ and perfect assortive mating on IQ. In other words, let’s see if “IQ clones” will be have enough similarity in wages to match the 0.4 intergenerational correlation of income.

Will the IQ clones have similar incomes? Not so much. (0.3^2)*1 still equals something small: 0.09. Less than 1/4 of the intergeneration correlation in income. Medium-sized potatoes, but we had to make a ton of ridiculous assumptions to get there.

It’s that doggone low correlation between IQ and wages, a correlation that has to be squared because we’re comparing parent to child. So a high heritability of IQ doesn’t imply a high heritability of IQ-caused-income. Another reminder that lots of things impact your wages: Not just how smart you are.

Gintis and Bowles work through some finger exercises to argue for big environmental effects, and that’s all well and good. But to my mind, the interesting fact is that income is still highly heritable!

G/B report that MZT (identical twin) earnings correlation is 0.56, and DZT (fraternal twin) earnings correlation is 0.36, so using the crudest of approximations, the heritability of earnings is still (0.56-0.36)*2=0.4. So income apparently has a modestly high heritability, but most of it can’t be explained by the IQ-wage channel. Looks like the genetic heritability of income is being driven mostly by non-IQ channels.

• Category: Economics, Science • Tags: Behavior Genetics, Economics, IQ 
🔊 Listen RSS

From Oded Galor and his promising grad student Quamrul Ashraf, another paper that ties together genes and group productivity.

Their big result (Figure 5 below) is that a population cluster’s genetic heterozygosity has a Goldilocks relationship with population density in 1500AD: Too much heterozygosity (Sub-Saharan Africa) or too little heterozygosity (Americas) predicts low population density. And in a pre-modern world (heck, even in the modern world), population density is a rough measure of technological progress.

Surprisingly, the Goldilocks result holds even when you control for a bunch of other stuff like arable land and the timing of a population’s agricultural transition. And perhaps most surprisingly, the much-hyped correlation between latitude and population density vanishes when you control for pretty much anything in addition to latitude. So the “distance from the equator” variable that growth economists spend so much time on may just be epiphenomenal.

The authors admit they don’t have a great theory for why the warm porridge tastes best–the goal of their paper is basically to get the Goldilocks result out there for others to work on. Here’s hoping some economists take the bait…..

Bonus: Portfolio’s Zubin Jelveh gets Galor to comment on what all this means for Jared Diamond.

• Category: Economics, Science • Tags: Economics, Genetics 
🔊 Listen RSS

Slate has been having a debate on sex differences. Along the way, they hit on a key Summers issue: The apparent higher male variability of math scores. Shaffer, the author, refers to the classic Feingold piece, a cross-cultural meta-study of the variability of mental abilities across genders. Shaffer makes the common claim that there are data on both sides–sometimes women have a higher variance, and sometimes the men do. But is the difference statistically significant?

I did a simple analysis of Feingold’s data from 54 math tests from 20 countries, and 19 tests of spatial ability from 9 countries. I ran least squares and least absolute deviation tests.

Here are the p-values for the restriction that men and women have equal variability:

Math, least squares: p

• Category: Science 
🔊 Listen RSS

The subtitle, The Case for Genetic Screening, seems to say it all. But Cowan comes at the topic as an historian with an interest in medical ethics. Here’s how she makes her case:

1. She shows that historically the folks who came up with eugenics were different from the folks who came up with genetic screening. She is aware of the possibility of genetic fallacy, but I think she knows that people like it when their ideas flow from pure springs. She focuses on Tay-Sachs, beta-thalassemia, sickle-cell anemia, and PKU, showing that with the partial exception of sickle-cell, the drive for genetic testing came from parents whose children suffered from genetic diseases and from communities at high risk for the genetic disease. Thus, genetic screening is a bottom-up social phenomenon, not a top-down mandate. For the beta-thalassemia chapter, she spent some time on Cyprus, where the disease is relatively common, and her on-the-ground knowledge shows.

2. She shows that from a population genetics point of view there’s a big difference between eugenics and genetic screening. Eugenics, she says, is a system of encouraging the fit to bear more children and perhaps discouraging or preventing the unfit from bearing children. Eugenics thus promotes ‘good genes’ in the population, the literal translation of eugenics. Modern genetic screening, by contrast, makes it easier for those with bad genes to bear children for two reasons. First, screening lets people with deleterious recessives find partners without such recessives, so the recessive alleles still stay in the population. Second, screening makes couples who both have the same deleterious recessive allele more willing to bear children, since they know they can abort a homozygotic recessive fetus. She actually has some decent anecdotal data on the second point. Thus, she repeatedly emphasizes that genetic screening is simultaneously “anti-eugenic” and “pro-natalist.”

3. She tells a lot of human-interest stories about important firsts in genetic screening, focusing on happy endings. Given the importance of the law of small numbers, this is probably a good idea, and it’s a relatively painless way for her to show how science and medicine work in the real world.

The book is exceptionally well-written, and while her history of eugenics contains few surprises, her history of the successes and failures of genetic screening was quite gripping. She also covers the basics of Mendel from scratch, so feel free to hand the book to anyone who took high-school biology. Functionally, Cowan does the same thing for genetic screening that The New Republic did for tough-on-crime policies in the 80’s and 90’s: Cowan does some liberal hand-wringing while telling the reader that no, you’re not becoming a Brownshirt if you agree to an amnio…..

Related: Heredity and Hope: The Case for Genetic Screening by Ruth Schwartz Cowan.

• Category: Science • Tags: Bioethics 
🔊 Listen RSS

James R. Flynn is a philosopher and psychologist at the University of Otago in New Zealand, as well as Distinguished Associate of the Psychometrics Centre at Cambridge University. His best-known paper, “Massive IQ Gains in 14 Nations,” (Psych. Bulletin, 1987), documented what Herrnstein and Murray later called the “Flynn Effect”: A long term increase in average IQ’s across the developed world. This widely-reaffirmed result contradicted the folk wisdom that a coarsened culture and dysgenic fertility were making the rich nations less intelligent. In his new book, “What is Intelligence? Beyond the Flynn Effect,” (Cambridge University Press), he argues that changing social and economic forces can explain both the Flynn Effect and group differences in IQ. To fully understand the Flynn Effect, he contends, we need to understand the “cognitive history” of the 20th century. Perhaps most importantly, he proposes a variety of practical empirical tests so that one can see whether his explanations are correct.

The author of four books and dozens of articles in the fields of moral philosophy and psychology, Professor Flynn has repeatedly spurred psychologists to rethink exactly what it is that intelligence tests measure.

1. In your new book, What is Intelligence? Beyond the Flynn Effect, you emphasize that IQ research is so focused on g, the general factor of intelligence, that they’ve been unable to see other important features in the IQ data. In particular, the “g-men,” as you call them, seem to think that if the Flynn Effect is an overall increase in all IQ subtests, or an overall increase in a random subset of IQ subtests, then they can just ignore the Flynn Effect completely. So, what are the g-men missing out on?

Over time, changing social priorities alter the cognitive demands made on our minds. For example, society may want more and more people to put on scientific spectacles so they can understand the world rationally through education. IQ tests like Similarities and Raven’s pick this up as enhanced performance. Yet, thanks to a more visual culture, society may not require us to enlarge our vocabularies – meaning no higher scores on the WISC vocabulary subtest. These trends are of great significance. If you dismiss these trends because they do not tally with the various tests’ g-loadings, you miss all of that. G rather than social significance has become your criterion of what is important.

2. Over the decades, you’ve carried on an extensive correspondence with Arthur Jensen, the controversial and enormously influential intelligence researcher at UC Berkeley. You summarized some of your early thoughts about Jensen’s work in your 1980 book Race, IQ, and Jensen, a book that, in my opinion, sets the standard for how do discuss this controversial topic. What have you learned about Jensen over the years, and what have your interactions with him taught you about the nature of scientific research?

I never suspected Arthur Jensen of racial bias. Over the years, I have found him scrupulous in terms of professional ethics. He has never denied me access to his unpublished data. His work stands as an example of what John Stuart Mill meant when he said that being challenged in a way that is “upsetting” is to be welcomed not discouraged. Before Jensen, the notion that all races were genetically equal for cognitive ability had become a dead “Sunday truth” for which we could give no good reasons. Today we are infinitely more informed about group differences. Equally important, the debates Jensen began are revolutionizing the theory of intelligence and our understanding of how genes and environment interact.

3. In an earlier book, Asian Americans: Achievement Beyond IQ, you contended that Asians appeared to do just as well as Whites on IQ tests-no worse or no better, with the possible exception of some narrow visuospatial abilities. You showed, in fact, that a lot of the apparent high Asian IQ scores were driven by the Flynn Effect. Since then, a number of studies catalogued by Lynn and Vanhanen seem to reinforce the conventional wisdom that Asians are usually doing better than Whites on IQ tests. Are you still convinced that there’s no substantial difference in average IQ between whites and Asians, and if so, what’s wrong with the recent data?

The Chinese Americans I studied were the generation born in 1945-1949. They were no higher than whites even for non-verbal IQ yet out-performed whites by a huge margin in terms of eventual occupational status. That meant that they could give their own children the kind of privileged environment they had never had. The result was a pattern of IQ that put the subsequent generation of Chinese Americans at an IQ of 109 at say age six gradually falling to 103 by the late teens, as parental influence faded away in favor of peers. The extra 3 points the present generation has as adults is due to the fact that they are in cognitively more demanding universities and professions and because they have internalized a positive attitude to cognitively challenging activities and companions.

4. At least at first glance, reading comprehension appears to involve a high degree of abstraction. If, as you argue in your new book, the Flynn Effect is largely driven by an exogenous rise in abstract thinking, then why hasn’t the reading comprehension score increased by very much?

The Comprehension subtest of the WISC does show significant gains, though not nearly as great as Similarities and Raven’s. But it is not a test of reading comprehension but a test of perceiving the “logic” of social arrangements – for example, why streets are numbered in order. The reading tests of the Nation’s Report Card show no gain at age 17 because you are expected to read adult novels. Since young people today have no larger vocabularies and funds of general information than their ancestors did, they cannot read these works with any greater understanding.

5. In What is Intelligence?, you discuss the importance of “Short Hand Abstractions” or “SHAs” as part of an educated person’s mental toolkit. What are they and how do they relate to your intelligence research?

IQ tests have missed a striking cognitive development of the 20th century, namely, that the various sciences and philosophy have enriched our minds by gradually giving educated peopl
e short-hand abstractions (SHAs) that allow us to critically analyze our world. For example, the word “market” no longer stands for a place but for the law of supply and demand and you can use it to see why rent controls are self defeating. The concept of “tautology” can make us more sophisticated about history. If someone says “Christianity has been a force for good”, and explains away all the slaughter Christians have perpetrated by saying that they “were not real Christians”, we can immediately see the flaw. If only good people qualify as Christians, the goodness of Christians has been established by definition! Sadly universities never give their graduates a full tool kit of these wonderful analytic concepts.

6. Recently, some IQ researchers have argued that if the Flynn Effect is g-loaded, then we should see a fall in the factor loadings across subtests over time. Their story is that cross-sectionally, we know that people with high IQ scores have more specificity–that is, they have greater strengths and weaknesses relative to the average person. Do you place much weight on that hypothesis, and do you think it might explain why IQ gains over time are distributed the way they are?

The IQ gains are not g-loaded so the prediction is beside the point. The importance of cognitive trends over time is a matter of their social utility. Whether they happen to be greatest on skills that have the highest g-loading is a distraction.
7. The Dickens-Flynn model (Psych. Review, 2001) attempts to explain the apparent high heritability of IQ by arguing that people with good genes end up endogenously in good environments, which in turn raises their IQs even more. In your new book, you propose a number of ways to test this hypothesis. Do you think that the Dickens-Flynn model is all that’s needed to explain differences in average IQ across ethnic groups, or do you think that other explanations might be needed?

The Dickens-Flynn model does nothing to evidence that IQ gaps between groups are environmental rather than genetic in origin. That evidence must come from specific environmental hypotheses about what handicaps (say) black Americans suffer as they age. What the model shows is that twin studies (which emphasize the effects of genetic differences between individuals) do nothing to prejudice an environmental explanation of group differences.

8. Out of the many research designs you propose in What is Intelligence, which one would you most like to see performed and why?

The one that calls for investigation of urban and rural Brazil. I think the former approximates where Americans are today, and the latter approximates where Americans were in 1900. We could get direct evidence for or against the cognitive history of Americans in the 20th century that my book relates.

9. You’ve long said that you disagree with Richard Lynn’s view that the Flynn Effect is largely driven by better nutrition. One of Lynn’s pieces of evidence is that IQ gains show up at very early ages, which would be surprising if the Flynn Effect were entirely sociological. Why do you think IQ gains show up at such an early age, and about what fraction of IQ gains do you think might be due to nutrition?

Changing ratios of adults to children in the home (smaller families) and changed modes of dealing with infants affect cognitive development from birth. The nutrition hypothesis explains little in America since 1950 – the evidence is in the book.

10. You’ve shaken up the field of intelligence research every time you’ve published a book on the topic. What are you working on for your next project?

My next book is in press. It will be called: The hollow center: race, class, and ideas in America. It will attempt to shake Americans into awareness that they are blind to the state of black America, that their foreign and domestic policies have perverse priorities, that they are class blind, and have lost their way it terms of Jefferson’s humane ideals. It is, however, a hopeful book in the sense that there is much in America’s history that can show us how to find our way.

• Category: Science • Tags: Psychology 
🔊 Listen RSS

In economics, a rule of thumb is that an academic article that largely agrees with Herrnstein and Murray’s The Bell Curve must start off by attacking The Bell Curve–maybe it’s just a way to get past peer review, maybe it’s a way of keeping your status in the academic community, maybe it’s because they didn’t understand or read H&M, could be all of the above.

The same is now apparently true with discussions of women in science: When arguing that the link between gender and scientific abilities is subtle and complex, it’s apparently mandatory to attack Larry Summers for being simplistic, even though he himself noted that the relationship was very likely to be subtle and complex.

Latest example: Scientific American.

If Larry Summers’s comments had one appealing feature, it was the benefit of simplicity…however, the truth is not so simple.

The multiple authors at SciAm march through the various hypotheses: work expectations, biology, glass ceilings. And they’re honest enough to point out that there’s some evidence for all three hypotheses–and they even note the apparent role of pre-natal sex hormones in shaping brain development. Just as you’d expect, they find at least tentative evidence for all three stories.

But it looks like the SciAm folks didn’t even bother to look at Summers’s own remarks. If they had, they would have realized that Summers himself could have written the outline for their article (emphasis added):

There are three broad hypotheses about the sources of the very substantial disparities that this conference’s papers document and have been documented before with respect to the presence of women in high-end scientific professions. One is what I would call the-I’ll explain each of these in a few moments and comment on how important I think they are-the first is what I call the high-powered job hypothesis. The second is what I would call different availability of aptitude at the high end, and the third is what I would call different socialization and patterns of discrimination in a search. And in my own view, their importance probably ranks in exactly the order that I just described.

Work expectations, biology, glass ceilings. Yes, Summers weighs the alternatives differently than the SciAm folks, and yes, I’m conflating some issues in this short blog post, but you can read the articles yourself to double check the subtleties (e.g., the separate discussions of “abilities” and “biology.”). But the main point is that there’s nothing “simple” about Summers’s story.

Just at Jason noted about the press’s treatment of James Watson, so too with Summers: The popular scientific press rarely let the facts get in the way of a good plotline. The “Summers was simplistic, but the truth is complex” plotline is just too handy. Unfortunately for Scientific American, Summers, despite his reputation as a reductionistic economist, didn’t fall for a “simple” explanation.

• Category: Science 
🔊 Listen RSS

Economists Oded Galor of Brown and Omer Moav of Hebrew U. argue in a new paper that the Agricultural Revolution created longer lifespans. A simple version of their model goes like this:

Agriculture–>Disease–>Somatic Investment in stronger bodies–>Longer lifespans once things settle down.

This result hoists Jared Diamond on his own petard: If the Agricultural Revolution really did make life worse (as he frequently argues), then the forces of evolution would have noticed that fact and reacted in some way. Galor and Moav argue that evolution would respond by building stronger bodies in high-disease environments, and the result would be longer lifespans once those dangers of disease recede in the modern world.

More importantly, Galor and Moav argue that we’re still living through the Agricultural Revolution: Groups that went agricultural early on went thorough bigger genetic changes. That means that early agriculture should cause longer lifespans.

An interesting theory, but what’s the evidence? They use Putterman’s new estimates of the year that countries went agricultural, control for a lot of the usual suspects, and find this:

[C]ontrolling for geographical and continental characteristics of each country, as well as income, education and health expenditure per capita, every 1000 years of earlier Neolithic transition contributes to life expectancy 1.6-1.9 years.

A couple of facts about the agricultural transition: The differences across countries are big, according to Putterman:

The average country went agricultural about 4500 years ago (mean and median within a couple of hundred years).

Standard deviation: 2400 years.

10th percentile: 1500 years ago (mostly sub-Saharan countries, plus some New World countries)

90th percentile: 8000 years ago (Eastern and Southern European countries–the Middle East was earlier).

So the cross-country differences appear big enough to be evolutionarily important a priori.

But back to Galor and Moav’s big result: Almost 2 years of life for a thousand years of agriculture: Maybe that number will become a new stylized fact in the economics-and-evolution literature. It’ll be interesting to see if this result comes up in political debates over health care reform…..

• Category: Economics, Science • Tags: Economics, Evolution 
🔊 Listen RSS

Couldn’t find a thread on this yet: Actor/Politico/Author Ben Stein has apparently become a “You can’t handle the truth“er. He appears in a documentary on the persecution of the intelligent design movement *yawn* but here’s his key claim:

…[Stein] said in a telephone interview that he accepted the producers’ invitation to participate in the film not because he disavows the theory of evolution – he said there was a “very high likelihood” that Darwin was on to something – but because he does not accept that evolution alone can explain life on earth.

He said he also believed the theory of evolution leads to racism and ultimately genocide, an idea common among creationist thinkers. If it were up to him, he said, the film would be called “From Darwin to Hitler.”

So it’s not that he doesn’t believe in evolution, it’s (partially) that he doesn’t trust the masses with the knowledge. There, he could be onto something…..

Related: I’m in the middle of reading Watson’s very entertaining Avoid Boring [Other] People, and he notes that at his 1946 U Chicago commencement, the university president said the only hope of avoiding disasters like WWII was to believe in the “brotherhood of man,” a belief that was supposedly impossible without a parallel belief in the “fatherhood of God.” Watson has a lot of great things to say about religion so far–no surprises, but still fun.

He also has a lot of good academic career advice in handy numbered lists at the end of each chapter (e.g., “Have friends close to those who rule,” “Channel rage through intermediaries,” “Extend yourself intellectually through courses that initially frighten you,” etc.,).

• Category: Science • Tags: Evolution, Intelligent Design, Watson 
🔊 Listen RSS

In this invited address to the American Psychological Association, Roy Baumeister has quite a lot of fun with his topic: “Is there anything good about men?” His major themes will be familiar to GNXP regulars–Larry Summers, the high male variance of IQ, genetic and cultural explanations, a rejection of the culture war and a call for science–but it’s a tale well told. A typical quote:

[M]en really are better AND worse than women.

Great to see the APA having this kind of discussion.

(Hat tip: Bryan Caplan of Econlog.)

• Category: Science 
The “war hero” candidate buried information about POWs left behind in Vietnam.
Are elite university admissions based on meritocracy and diversity as claimed?
The sources of America’s immigration problems—and a possible solution