Colder climates favor civilization even among Whites alone

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Last year I had a crazy idea about how winged insects might influence civilization. I only pointed to winged insects as an exemplar, not to suggest a “Mosquito Theory of History” or something stupid and sexy like that. The reasoning is simple: insects are more likely to be winged in certain climates, and that means more effective vectors of disease in such environments; and a greater disease burden makes you dumber, more tired, and more irritable, which stunts the growth of civilization. [1] A qualitative follow-up post looked at where civilizations have ever appeared, and in what climate types they existed.

Well, now I’ve done some quantitative work, and it turns out that I was right. One critique against an international study is that natural selection may have adapted people to be more or less civilized in different environments, so that the only influence of climate is as a selection pressure for genetic change. There are at least two such studies already out there: one by Templer & Arikawa (2006) and another by Vanhanen (2004). I’m arguing that it matters even when people start out pretty much the same genetically, so I will look just at the US. It varies enough in climate and degree of civilization that any correlation should jump out.

Motivation

In particular, I will look at the correlation, on the level of states, between average annual temperature and the average IQ of Whites, post-secondary degrees awarded to Whites per capita, and the percent of the White population that’s imprisoned. I only look at Whites in order to avoid the confound of climate with racial composition (for example, the cold Mountain states are heavily White, while Blacks make up a larger fraction in the hot Southeast).

The reason I look at basic measures like IQ or being in jail, as opposed to the loftier things we associate with civilization, is that smarts is the key determinant of propelling the institutions of civilization forward, while crime gives us a good rough idea of how barbaric we are on a personal level. I’m sure that governments can improve or screw things up too, but it’s the raw cognitive and behavioral materials that matter most, as Lynn and Varhanen show in IQ and the Wealth of Nations (see all GNXP posts on this topic). Moreover, studies of representative samples of the population always show a strong influence of IQ on how cultured a person is. See, for example, a National Endowment for the Arts report on the demographics of arts attendees (PDF p. 19), which shows that attendance increases nearly monotonically by education level.

The results

As you can see, hotter average temperature is associated with lower White IQs, fewer degrees being awarded to Whites per capita, and a higher percentage of the White population being imprisoned. The relationship looks pretty linear in each case, and the data are on an interval scale, so we check the Pearson correlation coefficient: between White IQ and temperature, it is -0.48 (p = 0.0005, two-tailed); between degrees to Whites and temperature, it is -0.57 (p = 0.00002, two-tailed); and between percent of Whites in jail and temperature, it is +.40 (p = 0.005, two-tailed). Even conservatively correcting for three independent hypotheses still leaves all results significant (and IQ and getting a college degree are not even independent). At any rate, average temperature accounts for 23%, 32%, and 16% of the variance in White IQ, degrees to Whites, and percent of Whites in jail, respectively — pretty damn good for social science. [2]

Methods

I took the average annual temperature for each of the 48 continental states (Alaska and Hawaii were not included in the source, so I left them out). Next, I used Audacious Epigone’s estimates of White IQ by state, which are based on NAEP data from 8th grade math and science test scores (read about his methods here). I turned to Statemaster.com for the per capita number of post-secondary degrees awarded to Whites. For the number of Whites in prison per 100K Whites in the state’s population, I used the data from 1997 in a study by the National Center on Institutions and Alternatives (PDF here), which separates non-Hispanic Whites from Hispanics, unlike most crime data from government agencies. [3]

Discussion

Here, correlation probably is causation, as climate precedes the other three variables in causality, and again because these are unlikely to be genetic differences that reflect adaptation to different environments — one of the few cases where natural selection “has not had enough time.”

An objection is that the differences could reflect a “brain drain,” whereby smart people flock to colder states, and their smart children boost the state’s NAEP scores. Even in this case, where climate does not cause group differences in IQ, it still confirms the hypothesis that colder climates favor civilization — why else would smarties flock there? But I doubt this anyway, since Montana, Wyoming, and North and South Dakota are not exactly fonts of civilization that smarties pour into, yet they have White IQs on par with the highly developed New York City metro area.

If it is causation, as seems likely, the mechanism could be anything. Pathogen load is surely part of it, hence the fields of study called “tropical disease” and “tropical medicine.” Also, you might sweat too much in hotter environments, bringing you closer to dehydration. As mild as these effects may seem, when accumulated over the course of development, they could result in your body spending more resources on bodily maintenance than on luxury items like IQ and toil. Heat could also just make you more fatigued — that wouldn’t affect IQ, but it would affect your work ethic, making you less likely to complete college and more likely to pursue quick fixes like crime to get what you want.

The correlation is stronger for getting a college degree than performance on 8th grade math and science tests, and that could be because college work is more g-loaded, because it also taps into work ethic aside from IQ, and because out-of-staters show up in the college figures but not the 8th grade figures. As tough as the environment may seem to natives, it must seem unbearable to college students raised in a different climate.

To the best of my knowledge, as the saying goes, this is the first demonstration of an association between climate type and IQ, civilization-related achievement, and crime, even among a population that’s pretty homogenous genetically (for the traits of interest, at least). Even what genetic diversity there is among Whites would underestimate the effect — Whites adapted to hotter environments, such as Italians and Greeks, are far more concentrated in the colder states within the US. To put the final nail in the coffin, though, you’d want to look at babies of Whites who are adopted into White families in a state of noticeably different temperature than that of the biological parents.

Still, it seems pretty unavoidable: hotter environments are less conducive to civilization, at least for Whites, and not just in extreme cases like the failed attempt to colonize sub-Saharan Africa. Civilization may have started in hot areas, but that was then. It apparently flourishes much more in colder climates. Just as we provide iodine in table salt to prevent a nutrient deficiency from lowering IQ, it might be just as well to encourage people to settle colder areas.

It’s not like they’d be abandoning civilization — just the opposite. They could take their accents, music, and whatever else with them, but they would not suffer the environmental insults that lower their group’s IQ, lower their ability to get a college degree, and make them more likely to commit crime. Fortunately for them — and unfortunately for current residents — the Mountain states have incredibly low population densities and could absorb some Whites from hotter states. That would certainly burden the locals for a generation, but again since lower White IQ in the Southeast is probably due to largely treatable environmental causes, it won’t take long for them to contribute as citizens on the same level as the locals.

Notes

[1] Underlying this is likely a tendency for all sorts of things to be more migratory in such environments — winged insects were chosen because there’s lots of solid data to illustrate the point. Basically, environments that are highly unstable favor migratory features since your environment may go from good to bad from one day to the next, or from one spot to the next — and being able to quickly move on to greener pastures will be well worth it. When environmental quality does not change much in space or time, then the expensive wings (or whatever) will not pay off.

[2] If you don’t have statistical software, you can do a lot for free on Wessa.net, including correlation.

[3] Although I didn’t run a test of normality on the distributions for temperature, iq, degrees, or crime, I did check the skewness of all, and only crime was significantly skewed: for crime, skewness is +2.1 standard errors of skewness (SES); for temperature, +1.24 SES; for degrees, +0.35 SES; and for IQ, -1.51 SES.

Addendum from Razib: I put up a related post at my other weblog.

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122 Comments

  1. Hmmm… could it just be that cold climates mean that people are more likely to stay in and read rather than go out and cause trouble. 
     
    Wonder if the incarceration rate has a negative correlation with precipitation.

  2. Is there a potential confounding variable in what might be called the Albion’s Seed Effect? – that the climate-oriented civilizational patterns you’re seeing are more (or to a large extent) the result of 300-year-old settlement patterns from England rather than current climate?

  3. A better title might be “Less Sticky climates favor civilization even among Whites alone”. It’s sizzling hot in the middle east/mesopotamia and yet that was “the cradle of civilization.” Also, when stickiness is equal, such as between western europe vs. northern europe, the colder place doesn’t do better, in fact it does worse!

  4. Great. The threat of global warming just took on a whole new dimension.

  5. Now do the same analysis for China, please! In the U.S., there’s a stereotype that Southerners aren’t as bright on average as Northerners, and I guess you’re saying that this stereotype has a degree of validity. Here in China, the stereotype is the reverse.

  6. Assume that people emigrate because they find it hard to progress in a mature society where there is lots of competition, with the niches all full. The “Scots-Irish” of the south had emigrated twice – once from Scotland and the English borders to Ireland, and then from Ireland to the US. So they had twice been filtered to leave behind the people who could cope with high levels of competition. Whereas the Puritans of the north had been filtered only once.

  7. The “Scots-Irish” of the south had emigrated twice – once from Scotland and the English borders to Ireland, 
     
    according to albion’s seed these were exemplars, but there were plenty who came directly from the borders as well. 
     
    It’s sizzling hot in the middle east/mesopotamia and yet that was “the cradle of civilization.”  
     
    *during the summer* in dec-jan the average high is less than 70 and the low less than 50. i think there are other dimensions that might be analyzed such as humidity, and the average low temperatures across the year (which might have a culling effect on pathogens annually). 
     
    Is there a potential confounding variable in what might be called the Albion’s Seed Effect? – that the climate-oriented civilizational patterns you’re seeing are more (or to a large extent) the result of 300-year-old settlement patterns from England rather than current climate? 
     
    i was wondering this too. perhaps a good way to check it would be to get data from appalachia, which spans southern pennsylvana to the northern part of alabama-georgia?

  8. Great post. Don’t stop at whites alone, do the same for blacks. The correlation between latitude and IQ firmly exists in the US when only whites or only blacks are considered. And the correlations are almost identical: .52 for whites (click here for visual representation of estimated white IQ by state) and .51 for blacks (here for visual). (The correlation between latitude and average annual temperature is surely robust, as our correlations with IQ are almost the same). 
     
    Some other speculations on why the farther north you head the smarter the population tends to become: 
     
    Regarding whites, the English Puritan families of the northeast that had become established and affluent stayed put while those with less to leave had more to gain by heading out onto the frontier. Whites working in the South as indentured servants made up a large portion of the labor supply early in the 1600s until well into the 18th Century. This was the ticket to the New World for many Europeans with few prospects at home, and sometimes even presented convicts a way to avoid prison time. Give consideration also to how the gullible types, hoping to strike it rich, flocked to California in the 1840s and 1850s with dreams that, for the most part, didn’t quite ‘pan’ out. A rebirth of the California Dream pulled destitute menials from the Heartland to the Southwest during the Great Depression (a la The Grapes of Wrath). 
     
    Regarding blacks, those in southern states tend to, with exceptions, have less European ancestry than those in the north. Pulling off successful escapes from the antebellum South could have selected for intelligence among those who were able to do so as well. 
     
    Contemporarily, for both whites and blacks, warmer climates produce a greater demand for outdoorsy labor (landscapping, lawn mowing, construction, tourism, etc), which tend to have low skill-level requirements. That rougher climates selected for attributes to attenuate the physical threats posed by severe cold, while also selecting for greater intelligence to deal with more scarcity, may mean that, on average, smarter people are less bothered by chilly weather. Personal experience suggests it to me.

  9. I like Audacious Epigone’s comments about the initial stocks being different in the North and South. That, along with slavery, helps to explain the earlier industrial and technological development in the North, which would have amplified the effects. 
     
    It seems like earlier industrial and technological development in the North would have attracted the higher-IQ Southerners. Conversely, since WWII there has been a lot of North-to-South migration. People who could do well for themselves in the North probably stayed; I’d guess it was mostly the ones who couldn’t find as good a job in the North who went to the comparatively low-wage South. Also, who is more likely to move south: a Northerner who wants to raise a family in a quiet suburban locale, or one who wants all the cultural amenities provided by sophisticated Northern cities? And which has a higher IQ? (Think of Sailer’s “Baby Gap” work.) 
     
    So in the 19th century there were “pull factors” attracting high-IQ Southerners to the North, and in the 20th century there were also “pull factors” attracting lower-IQ Northerners to the South. 
     
    The equality between the Dakotas and New York City probably can be explained by the Dakotas being almost all Northern European, while New York City has lots of Southern Europeans. That effect would make up for the opposite effect of the “brain drain” attracting people to New York. You can’t just discount the “brain drain” hypothesis, though. It seems like one of the most significant factors. 
     
    I remain skeptical that there is an environmental factor that would continue to depress Southern IQ to this day, as opposed to something like malaria that affected people in the past. I can name plenty of diseases that still affect people in Africa and other tropical regions of the Third World, but I can’t name anything that Southerners in this country suffer from that Northerners don’t.

  10. Conversely, since WWII there has been a lot of North-to-South migration. People who could do well for themselves in the North probably stayed; I’d guess it was mostly the ones who couldn’t find as good a job in the North who went to the comparatively low-wage South. 
     
    exactly! look at all those northerners who are moving to austin, the research triangle and south florida. it’s because they’re attracted to low-skilled work. also the hard work that residents of fairfax county do day to day. 
     
     
    The equality between the Dakotas and New York City probably can be explained by the Dakotas being almost all Northern European, while New York City has lots of Southern Europeans. That effect would make up for the opposite effect of the “brain drain” attracting people to New York. You can’t just discount the “brain drain” hypothesis, though. It seems like one of the most significant factors. 
     
     
    new york city has a lot of ashkenazi jews too.  
     
    let’s not ignore facts which reduce the probability of our assertions, shall we? ;-) (assuming we know facts)

  11. does this work for the Southern Hemisphere?

  12. Here is the previous gnxp post on Templer/Arikawa. They find the relationship between latitude/temperature and IQ both within and between continents. At the bottom I linked to Audacious Epigone’s post that the same relationship exists within races within the US.  
     
    As I’ve stated before, an interesting experiment would be to test the intelligence of related animals (such as common house pets) in the north and south. Are, say, German shepherds in North Dakota more quick-witted than German shepherds in Georgia? Cross-fostering would be completely feasible. Such an experiment might reveal important environmental effects on IQ. 
     
    (In nature, btw, there is no relationship between coldness and intelligence for species of animals – so it would more likely be an environmental rather than evolutionary effect)

  13. does this work for the Southern Hemisphere? 
     
    they call queensland the “deep north” in oz :-)

  14. Extremely extremely interesting and thought-provocative research. But the data isn’t perfect. A LOT of times, the center of population of the state is *drastically* different in climate from the rest of the state. (this probably won’t change the overall correlation, but it may change some data figures). Some examples: 
     
    States with centers of population much warmer than average state:  
     
    Colorado: Denver (avg. temp 50), Colorado Springs (avg temp 48), Grand Junction and Pueblo (avg temp 53), compare with average state temperature of 45 
    Idaho: Boise (avg. temp 51) is very warm compared to rest of Idaho 
    Washington: Seattle (avg. temp 53) 
    Oregon: Portland 
    New York: New York City is in extreme southeast of state, the northern parts are much cooler 
    Pennsylvania: Philadelphia is in extreme southeast and much warmer than the rest of the state 
    Maine: Portland, ME is in extreme southeast 
    Wyoming: Cheyenne and Casper are generally warmer than the western half of the state 
    Nevada: Las Vegas is exceptionally hot relative to an otherwise cool state 
    California 
    Wisconsin, Minnesota, and most of the other northern states probably fit as well but I don’t have data on those 
     
    States with Centers of population much cooler than average state: 
     
    Illinois: Chicago much cooler than rest of state. 
    Arizona: Phoenix + Tucson are v. hot relative to other areas of the state 
     
    So this could weaken the correlation, perhaps, since the centers of population of northern states tend to be in the warmer regions of them. Mountain states are also cooler than other states, and the centers of population of mountain states tend to be in the relatively warm lowlands of them.

  15. Also, the relationship would probably be reversed in Germany, which, if I’m remembering correctly, has higher IQ in the south.

  16. Ugh, I made a mistake, put Arizona into the first category.  
     
    Actually though, other than Illinois, there don’t seem to be many states with centers of population cooler than the average state temperature (that being said, the United States is generally relatively cool). This is different for the rest of the world though, especially the tropics, where the capitals often tend to be in the cooler regions of the hotter countries (e.g. Nairobi, Mexico City, Quito, Bogota, La Paz). In Europe, the northern capitals tend to be warmer than the rest of their respective countries, but the temperature variation within European countries doesn’t seem to be as high as that within countries in, say, Asia

  17. Razib, according to the map, the states you mention defy the pattern at least in the case of Texas and Virginia. Those are abnormally intelligent for their latitude. Florida has always attracted a lot of Northerners anyway. 
     
    You make a good point about the NYC Jews; I was just trying to suggest we should compare apples to apples. Do we know if the Jews pull up the NYC average enough to compensate for lower-IQ ethnic groups there? Also, comparing a state to a single city doesn’t seem like proper methodology in any case. 
     
    Agnostic’s conclusion is not necessarily wrong; I just don’t see enough evidence for it to be totally convincing. 
     
    I would tend to say the high performance in the North Central states is more due to the source of the people, being almost exclusively from the highest-IQ groups in Europe, whereas in the Northeast it might have more to do with attracting top talent from elsewhere, though offset somewhat by the presence of lower-IQ groups.

  18. Razib, according to the map, the states you mention defy the pattern at least in the case of Texas and Virginia.  
     
    yes, i was being sarcastic about your point about the post world war ii migration to the south. i’m sure there were low skilled people that moved, but a lot of the shift has been driven by the rise of post-agricultural economy which required high skilled workers. e.g., the research triangle in NC and northern virgina being classical examples, but also the information economy in cities like dallas, houston and austin. 
     
    Florida has always attracted a lot of Northerners anyway. 
     
    southeast florida has the second highest proportion of jews in the usa outside of new york. the nothern transformation there isn’t one of low skilled labor, it’s retirees. 
     
    I just don’t see enough evidence for it to be totally convincing. 
     
    that’s a fair point, but frankly your comment above indicates you haven’t thought much about the real nature of migrations as opposed to what you might assume based on your model. your predictions are obviously wrong because the data isn’t mysteriously hidden away, you can find the nature of north-south white migration post world war ii in standard sociology texts. so i appropriately re-weight the value of your opinion based on the proven quality of your knowledge base and the minimal constraint it seems to make upon the inferences you generate from your priors. and i assume others will as well.

  19. “they call queensland the “deep north” in oz :-)” 
     
    Yep. South is north and north is south. And it really is – Victoria is like their New England (settled, rich, prosperous, educated, etc.)

  20. Couldn’t this just be because better weather drives up property values, and only smart people are wealthy enough to afford houses in those climates?

  21. Couldn’t this just be because better weather drives up property values, and only smart people are wealthy enough to afford houses in those climates? 
     
    look, i don’t want to be rude, but please think before you post. do a quick check. yes, property values are high in the eastern and western enclaves…but are they that high in montana, the dakotas, minnesota, iowa and wisconsin? additionally, who would really say new england weather is ‘better’? yes, less disease, but it ain’t san diego for sure. and minnesota isn’t good weather either.

  22. Razib, 
    Very interesting post. I think there’s little doubt about work-ethic and the effect of climate on work-culture (Los Angeles and Rome are not known for their workaholics the way New York and London are).  
     
    As for IQ; weather is definitely the sort of thing people have a “taste for.” Are tastes/sensitivities to weather uncorrelated with IQ? It seems unlikely that there is no correlation at all, but I’m not sure what data to look at. My guess — White’s hate hot and humid more than they hate cold (admittedly just a guess). 
     
    A minor criticism: I think using states (instead of population) as your unit of measure is probably a bit misleading.

  23. I think it’s an interesting finding. However, some criticisms: 
     
    Intuitively, one would reason that heat and weather become less of an issue given that people spend less and less time outdoors (i.e. people are air conditioned for the majority of the day). 
     
    The types of intelligence required to thrive in a rural and urban setting are vastly different, and the ability to quantify those differences has escaped psychologists for decades. The ‘put a yuppie on a tractor’ bit. This could potentially weaken the IQ findings. 
     
    Degrees earned by whites also poses a problem. It would be interesting to see how this correlation looks if results are normalized for the # of prestigious universities in each state (measured by some kind of impact factor?).  
     
    The white crime rate would also be interesting to compare to state unemployment rates. Given that employment rates would probably be higher in colder, more urban centres (assuming of course that employment is a function of economy, and not temperature), it only makes sense that a higher proportion of people commit crimes in hotter states with lower employment rates. 
     
    I get the whole ‘tropical disease’ point of view. It’s interesting, but there are so many angles here. And with the advent of Google, one can find a correlation in just about anything: 
     
    http://scienceblogs.com/goodmath/2008/07/petabyte_scale_dataanalysis_an.php

  24. I’ll respond more in-depth after I’ve had my caffeine, but just re: this – 
     
    And with the advent of Google, one can find a correlation in just about anything: 
     
    To wave away the significance of the correlations that I found, you’d need to show that I tested 2500 independent hypotheses for the heat / degrees to Whites correlation, 100 for heat / IQ, and 10 for heat / crime. However, I tested 3. 
     
    Sometimes you “find a correlation in just about anything” by chance, but that’s why Bonferroni corrections are there. Other times, you find a correlation in just about anything because pieces of the world fit together. If it seems easy to do, that’s because it is — I did all of this work in an afternoon or two, all on the internet and Excel.

  25. The types of intelligence required to thrive in a rural and urban setting are vastly different, and the ability to quantify those differences has escaped psychologists for decades. 
     
    two words: UPPER MIDWEST
     
    many of the objections are premised on southern differences from the northeast, but the upper midwest is an immediate rejoinder. so what’s different between whites in the south and the upper midwest? ethnicity, yes, more germans and scandinavians vs. more british isles in the south. climate as well. various historical and economic differences.

  26. “Razib, 
    Very interesting post.” 
     
    the author of the post is assman. just an fyi.

  27. Sorry, I’m totally not buying this. Are you seriously arguing that “disease burden” is the major causative factor in “degree of civilization” among US states? 
     
    What nonsense is this that climate “precedes” the other three variables and therefore must be causative? There’s a reason you left blacks out of your analysis — to avoid a confounding factor. So your conclusion that heat “must” be the causative factor is erroneous — there could be an overlooked “confound”.  
     
    Let’s look at an obvious, alternative explanation that avoids the insect-vector hypothesis. 
     
    How about, I don’t know, the Civil War? Hot states lost. The losing states stayed impoverished for over a generation in people, money, infrastructure, and political muscle, giving the North a huge, long-term educational advantage. Or do you attribute the South’s loss to the inevitable effects “disease burden”?  
     
    There are so many variables that correlate with “heat” in the US — not just mosquitoes but vegetation, politics, religion, caloric intake, rates of military service, etc. etc. I would believe all of those have an effect on education level and IQ before I believed that “disease burden” is the major causative factor in “degree of civilization” among US states.

  28. Hey Ralph, did Arizona and New Mexican Whites lose in the Civil War? Cuz they live in hot states and have lower IQs than elsewhere. 
     
    I left out Blacks because if I included them, someone would say, “Well, sure the average IQ of the Southeast is low compared to Montana and the Dakotas — they have a lot more Blacks.” 
     
    Try not being a dumbass next time you comment.

  29. What about humidity and heat, my anecdotal feeling is that where tis humid civilization falters a bit.

  30. my anecdotal feeling is that where tis humid civilization falters a bit. 
     
    anyone who lives on the west coast can tell you that is totally true ;-)

  31. So your conclusion that heat “must” be the causative factor is erroneous  
     
    what the fuck? ;-) what’s up with the quote, assman didn’t even say that! 
     
    The losing states stayed impoverished for over a generation in people, money, infrastructure, and political muscle, giving the North a huge, long-term educational advantage 
     
    this retarded because the north already had a huge educational advantage. also, as a matter of fact reconstruction was not over a generation, it was less than a generation. not only are you a dumbass, but you’re a sloppy dumbass, ironic given your ostensible factual critique (there’s also the not-too-small point that you seem to stupidly imagine that federal investments on the scale of the new deal era and later can be anachronistically back-projected to the 19th century).

  32. OK, I’ll let Razib comment more on the Albion’s Seed stuff (also over at his ScienceBlogs post), but as he’s already said, I’m not talking about the Southeast vs. the Northeast — I am talking about the entire country, and on the level of states, not regions. 
     
    Even within the Mountain states, IQs get lower as you increase in heat from Montana to Arizona and New Mexico. IQs decrease monotonically going southward from North Dakota to Oklahoma. 
     
    Losing the Civil War has zero to do with current IQs — god, you’d only find a dopier explanation from Dick Lewontin himself about why Blacks score lower than Whites. Southerners have modern schools, textbooks, tutoring companies, bla bla bla. 
     
    When I say “disease burden,” I am not talking about malaria, typhoid, or anything else we’ve gotten rid of. I’m talking about the gajillion bugs that you don’t even know you have, and that we don’t even know what they’re doing. 
     
    It’s common knowledge among nerds now that Toxoplasma Gondii affects human behavior, but it wasn’t well known very long ago. There are surely many other examples of harm to humans caused over the long-term by pathogens — see Cochran, Ewald, & Cochran’s (2000) “New germ theory of disease” article (called “Infectious Causation of Disease: An Evolutionary Perspective”). That’s why I’m using heat — we have no measurements of the concentration of all these largely unknown pathogens. We do know that pathogen concentration correlates with heat, so that’s the proxy we use. 
     
    That’s another reason why air conditioning may not have totally remedied the bad environment: it will cool you off, but it won’t kill bugs or pathogens (unless you turn it to winter-like temperatures, I suppose). 
     
    You don’t want to normalize the degrees awarded to Whites by taking into account the number of universities because that obscures the relationship between climate and degree of civilization. Let’s say each college ended up granting identical numbers of degrees to Whites in Alabama and in Massachusetts. You would totally miss the fact that Massachusetts has far many more elite colleges per capita — because it is a more advanced state. 
     
    I initially planned to use “number of colleges per capita” instead of degrees awarded per capita, but number of colleges doesn’t give us data on Whites only. Plus, if the college just sits there, it doesn’t tell us how developed a state is, while if people are making good use of it and earning degrees, we get a better idea.

  33. Fair enough razib and agnostic. You make good counter-arguments, and I’m no social-scientist or statistician. But I still say there’s not that much to discuss until we add in a more direct link to support the ‘pathogen’ hypothesis. I must admit, I have no interest in doing the analysis myself, but does the CDC keep any useful records regarding west nile, malaria, etc…? Or are we talking just a general ‘blah’ feeling about being humid? I’m Brazilian, and I have to tell you, I love heat and humidity.

  34. My bad didn’t read your latest post agnostic… so basically your hypothesis is irrefutable, because it could be anything. Well that’s no fun.

  35. An interesting case, but as someone once said, what of South China? Or for that matter, Japan? I have no idea how they did anything here between late May and early September before air conditioning, and as the historical and archeological records show, both places were rife with cyclical seasonal epidemics and parasitic infections respectively. 
     
    As it is, climate strikes me as a contributive factor contingent on certain priors, not a decisive one. The climactic difference between say Knoxville and Charleston is striking, much less to say Yuma and Flagstaff. In terms of pathogen load, New Orleans and Tucson are apt to be quite different, just as the macrofauna is quite different for both areas, so should the microfauna.  
     
    Add to that the historical factors such as the Albion’s Seed thing, the phenomenon of post-Civil War brain drain until recently and well… you can see where this is going.

  36. the best comparison might be to closely look at scores in deep south states with a lowland and appalachian sector. south carolina comes to mind as one of the more balanced ones.

  37. so basically your hypothesis is irrefutable, because it could be anything. Well that’s no fun. 
     
    My hypothesis about climate and civilization is irrefutable because the data make it so. My hypothesis that the part of the mechanism is pathogens is difficult to test, but so are all germ theories. That’s why no one believed Semmelweis — “Oh, so anything could be killing these women during childbirth? Well, then we don’t have to worry, until you deliver irrefutable proof.” 
     
    And until that irrefutable proof comes, Southerners will remain dumber and more crime-prone. Great… 
     
    Plus, my hypothesis about the mechanism makes a hell of a lot more sense than most of the alternatives I’ve heard.

  38. the best comparison might be to closely look at scores in deep south states with a lowland and appalachian sector. 
     
    Which states specifically? I’ll run another test and see what pops out — though the power to detect effects will be a lot lower with fewer data-points obviously.

  39. As it is, climate strikes me as a contributive factor contingent on certain priors, not a decisive one. The climactic difference between say Knoxville and Charleston is striking, much less to say Yuma and Flagstaff. 
     
    these specifics matter, but the key to me is systematic gradients. the research triangles, austin, etc., are islands of in-migration. local contingent events are just that, local.

  40. Well yes, they matter deeply, particularly in validation of this particular hypothesis, but still saying the whole Southern gradient is suffering from a relatively same affect? The same load hitting soggy Louisiana cannot be the same one hitting the dry and semi-alpine Arizona and New Mexico, which relatively speaking share more of their climactic range with the states to the north of them. 
     
    There’s too much apples and oranges here, plus chicken and eggs for me to think it’s a decisive factor, particularly when one looks at it in the global scale.

  41.  
    Which states specifically? I’ll run another test and see what pops out — though the power to detect effects will be a lot lower with fewer data-points obviously.
     
     
    south and north carolina. also tennessee and kentucky are bissected. georgia, alabama and mississipi have much smaller appalachian segments, but they have it.

  42. Oh, you mean just the Appalachian parts… hmmm, someone else can crunch county-level data!

  43. It’s an interesting idea, but aren’t there some historical considerations that cloud the picture, e. g. the long aftermath of the Civil War on the South for the whites (destroyed infrastructure and depleted population of males in their prime years, and generations of substandard, segregated schools for blacks starting with a generally low or non-existent literacy?  
     
    I wonder where you could get a population to make such a study without such factors. And what after all does IQ measure to begin with? If you gave a standard IQ test to a Chinese coolie working on the transcontinental railroad in 1864 how would it compare with a Chinese physics post-doc at MIT today?

  44. If you gave a standard IQ test to a Chinese coolie working on the transcontinental railroad in 1864 how would it compare with a Chinese physics post-doc at MIT today? 
     
    badly, cuz a MIT physics post-doc is REALLY, REALLY, smart by definition, even for physics phds. can we keep the analogies in the realm of useful information transmission? ;-)

  45. I think it pertinent to mention that the regional stereotypes in China impute greater intelligence and aptitude for business to people from the far warmer south. If you ask anyone in China – regardless of their geographic origin – about the difference between northerners and southerners, they will always mention the fact that southern Chinese possess a higher level of intelligence, and are better suited for entrepreneurship. Whenever I have asked northerners about this topic, they will shake their head with admiration, as they concede the superior intellect of their southern compatriots.  
     
    On the flip side, southerners are also supposed to be shrewd, calculating, effete and untrustworthy.  
     
    My suspicion has always been that the waves of immigrants who fled south from invasion of the Chinese heartland by pastoral nomads were comprised primarily of those who had the means: i.e. members of the landed gentry/scholar-official class. The people who remained were probably peasants yoked to the land, who then intermarried with the provisional master race of hardy Central Asians.

  46. Wait a sec… what if you were asked to decide solely on temperature which states suffer from the heat IQ deficiency.  
     
    Make 3 groups, one hot dumb group, one medium not-so-dumb-group, and one cold smart group or however you want to split it. 
     
    If you did a one way ANOVA on the IQ scores of the three groups, would the P-value be significant? Because then you’re using your model to make predictions… maybe even you could try your hand at other climatically similar countries.  
     
    Given the traveling patterns of individuals, and the lack of screening for unknown microbes, would you expect ‘unknown microbes’ to proliferate in other climates similar to the US? 
     
    And how do these predictions hold up for Canada? Do people in Yellowknife have higher IQ’s than people in Toronto or Vancouver? Very interesting post which raises a lot more questions than answers. 
     
    However I do take issue with one thing you said agnostic. Your data does not make anything irrefutable, you are only presenting data which suggests a lack of support for a null hypothesis. Significance is not ‘proof’.

  47. One aspect of modern civilization, is the aspect of hygiene. The microbes you speak of would have to cause ‘asymptomatic’ (i.e. no explosive diarrhea) behavioral changes, and have to be extremely resistant to many of the antibacterials commonly used in our society. As a biochemist I can vouch for the danger super-bugs, and for the complexity of immunology…  
     
    I can say it’s unlikely, but I’d definitely be intrigued by this new facet of microorganism… You’re proposing a sort gene outside the organism, which frankly I just find… cool.

  48. A great source of information on the interplay of climate and civilization is Ellsworth Huntington; in particular, take a look at MAINSPRINGS OF CIVILIZATION (PUB. 1945) and CIVILIZATION AND CLIMATE(3rd ed. 1924). The books are full of data on the relationship between climate and civilization; as a plus, since Huntington was, in essence, a pre-WW2 product, PC doublethink is almost entirely absent.

  49. Great stuff trajan23, thanks

  50. Regarding blacks, those in southern states tend to, with exceptions, have less European ancestry than those in the north.  
     
    Audacious, did you just make this up to prove your point? This is clearly incorrect.

  51. “Heat could also just make you more fatigued — that wouldn’t affect IQ, but it would affect your work ethic, making you less likely to complete college and more likely to pursue quick fixes like crime to get what you want.”  
     
    I think the above is a partial explanation along with the pathogens. As a 100% pure white guy who has lived in the following states: PA, VA, WA, CA, FL, IL, IN, OH, NC and MD, I can opine that heat is the enemy to the Northern European intellect and psychology. Hot climates feature something that makes life very difficult for some of us. Even the A/C cannot fend the overwhelming dreck that is life in Florida summer. As I write this, I have the A/C turned to 72 degrees, but I still feel blanketed in humidity.  
     
    From my experience, I believe that if you extracted the German and Irish from the South and sent them North, their children would be at the societal mean for intelligence. I have not noticed an overt lack of intelligence in Southerners compared to Northerns. Rather, I have noticed a malaise that reflects a climate to which we are not adapated. Moreover, as someone with severe eczema I am very susceptible to infection and I believe the pathogen theory has merit. I was never so sick in Seattle as in Palm Beach. I think there is something to the notion of small, intraceable infections affecting mental capacity and overall mood. My beautiful brown wife has noticed the same. Unfortunately, she is adapted for the heat and cannot stand the cold. However, my misery and the beauty of Boulder are prompting our relocation to that part of the country.  
     
    Brilliant post and brilliant work on GNXP. Since you are all employed or young enough, I will send $20 to Steve on your behalf.  
     
    Justin

  52. When we lived in Queensland, we admired the local wisdom: “For 4 months of the year it’s too hot to work and for the other 8 months it’s too nice to work”.

  53.  
    Audacious, did you just make this up to prove your point? This is clearly incorrect.
     
     
    i’m pretty sure he’s right, there’s data all the way back to classical markers which suggest.

  54. Agnostic, 
     
    An interesting book that contains some similar ideas about climate zones affecting personality and achievement, is this one I read over 20 years ago: 
     
    Heaven’s Breath: A Natural History of the Wind 
    by Lyall Watson 
     
    He drew correlations between people living in New England and North East Asia, as well as Ireland/Britain compared to the Pacific North West. 
     
    He felt that latter climate zone was optimal for academic achievement.

  55. Try not being a dumbass next time you comment. 
    I was certainly incredulous in my post, but I was not insulting. I simply suggested that historical and political factors that happen to trace temperature might be confounding an analysis that attempts to use heat as a proxy for “disease burden”, and I cited the Civil War as an example.  
     
    Apparently, though, only a “dumbass” could fail to recognize that Arizona’s test scores prove that the Civil War had no long-term impact on the education level of the American South. Apparently the genius of your approach and the barb of your wit is too much for a “dumbass” PhD like me to handle.  
     
    Sorry to have contaminated your discussion with professional, academic, skepticism; I won’t do it again.  
     
    Have fun with your blog.

  56. professional, academic, skepticism 
     
    lol. your phd didn’t prevent you from making obvious mistakes. if you can’t keep turds out of your own pool you expect us to take a dip? no thanks.

  57. “Actually though, other than Illinois, there don’t seem to be many states with centers of population cooler than the average state temperature”  
     
    Chicago is in a region of Illinois that is more strongly tied economically and socially to Wisconsin than to the rest of Illinois. The region that surrounds Chicago was once referred to as “South Wisconsin” and is also ethnically similiar to Wisconsin. The rest of Illinois, south of Interstate 80 or so, is really in the orbit of St. Louis and is very southern in many ways. Much of the region in Downstate Illinois was settled by southerners (Lincoln, who settled near Springfield, was from Kentucky) and the region still retains its ties to the south and to the southern Midwest, St. Louis and Kansas City. Southern Illinois also does not in general consider Chicago to be a part of Illinois.

  58. Not being an academic or a statistician, may I ask exactly what is meant by “civilisation” here? Is there an exact set of behaviours, structures, world views that you have in mind when you talk about that?

  59. “Regarding blacks, those in southern states tend to, with exceptions, have less European ancestry than those in the north.  
     
    Audacious, did you just make this up to prove your point? This is clearly incorrect.” 
     
    Actually Audacious is correct according to genetic and heredity studies that have appeared on places like, well, gnxp. The percentage of European ancestry is higher among blacks in northern states. Not by much, but it is higher.

  60. In regards to Lyall Watson’s theory regarding the Pacific Northwest as the optimal climatic zone, Huntington does something similar in MAINSPRINGS OF CIVILIZATION, arging that the optimal areas in the world for “High Efficency” are: Northwestern Europe (descrbed as a “rough rectangle with corners near Liverpool, Copenhagen, Berlin, and Paris”); the North American Atlantic zone, from New Hampshire to New Jersey;the Puget Sound area;the California coast;New Zealand; and the Southeastern Coast of Australia (p. 393).

  61. Concerning Chinese IQ. Over and over,in reading about IQ distribution, emphasis is placed on the difference between “northern” East Asians whose IQs average a little over 100, and southeeast Asians, whose IQs average below 100. 
    Question. Where’s the geographical division in China? While some Chinese have denied that this is true today, I have read that in the past there was a recognized division between the “high” nosed Chinese and the “low” nosed Chinese. Are the northern Chinese really dimmer, or just more phlegmatic, as Scandinavians and British are said to be.  
    A majority of Chinese are blood type O or B, but there is a large minority, centered in southern China, who are predominantly type A. The Japanese are also predominantly type A, also differing from other Asians who tend to type B and O, in that order.

  62. Again, in MAINSPRINGS OF CIVILIZATION, Huntington attempts to objectively analyze the relationship between climate and mental activity by studying the percentage of non-fiction versus fiction books in North American city libraries, the premise of the study being that readers of non-fiction are engaged in a somewhat more strenuous form of mental activity than readers of fiction (Barring, of course, such esoteric works as, say, ULYSSES). The data for the study comes from the 1920-1939 period. 
    8 most southerly cities in the survey:Tampa; Houston; New Orleans; Jacksonville; El Paso; Savannah; Shreveport; SAn Diego:Percentage of non-fiction in libraries:28.9 
    8 next most southerly cities:Atlanta; Los Angeles; Oklahoma City; Nashville; Richmond; Oakland; Kansas City; Cincinati:percentage non-fiction:51.3 (41.3 if L.A. is omitted). 
    6 more northerly cities:Baltimore; Denver; New Haven; Chicago; Boston; Hamilton, Ont.: percentage non-fiction:53.5 
    6 most northerly cities:St. John, N.B.;Minneapolis;Portland, Oregon;Seattle;Spokane;Vancouver: percentage non-fiction:55.2  
    (HUNTINGTON, MAINSPRINGS OF CIVILIZATION, P. 353).

  63. you should figure in flouridated water. 
    No, really. 
    makes you lethargic, an drops your iq. 
     
    thats why the germans were going to use it to poison the water supply in WWII

  64. A good 2/3 of China (at least in the east where over 75% of people live ) is tropical to subtropical. Most of Japan from Tokyo and south is tropical to Subtropical…only central Japan and the area of Tohoku and North to Hokkaido are colder than Subtropical. 
     
    There IQs are higher than most of Europe where there is similar climate along the Med. 
     
    What explains this?

  65. I should add that in East Asia…the Northern people were always barbarians. Even inside of present day China, Beijing was a city with a Han Chinese population but control by barbarians since the Later Jin Dynasty (in the 10th century) and was not ruled consistently by Han Chinese until the Ming Dynasty. Manchuria was obviously full of Tungustic barbarians and also Mongol-related peoples. No one ever accused these people of being the epitome of civilization in East Asia, in fact the opposite…even the Koreans considered them barbarians. It is true that many Turkic, Mongol, and Tungustic peoples were absorbed into the Han after the Sinified but great civilization was not created by these people. 
     
    They all lived in the North of China proper at the time. 
     
    Even today, the Chinese with the highest IQs and highest living standard live in Shanghai and South…one can argue this is due to history and not genes, but it is also known that when various barbaric tribes invaded and conquered Northern China, Han Chinese tended to flee South. This is why Cantonese call themselves Tong Yi (Tang Ren or Tang Dynasty People). 
     
    I say all of this to show that the premise does not hold for East Asia. Historically Cambodians (Khmer) were more advanced than people in Manchuria, Mongolia, and maybe even Korea at various periods. The Chinese spoke favorably of early Khmer society and these people were in a definite tropical zone. 
     
    Going back to Japan, Japanese civilization (Yayoi) is thought to have started in Northern Kyushu and/or Southern Honshu, and most of the history involves moving North and South from there…displacing and absorbing “barbarians” like the Ainu/Emishi. 
     
    So I’m not seeing this theory holding up.

  66. So I’m not seeing this theory holding up. 
     
    east asia, especially china, presents a really good objection IMO. that being said, there’s a lot of variables floating around. in plagues and peoples there was stuff about how much the han complained about the climate and disease in south china. there’s some genetic (see cavalli-sforza) and cultural anthropology and historical evidence that most south chinese dialect groups are compounds of han from north china and the indigenous peoples (e.g., there are cantonese marriage rituals which have analogs to those of nearby non-han people and none among other han). it may be that selection had more time to operate in china, where the north-south population exchanges and movements have been going on for 1,500 years, as opposed to 350 years for the united states. 
     
    the point about how beijing was never a stronghold of the han is well taken. most people do not know that manchuria became predominantly han only the last century or so (the manchus kept it as a reserve for their own ethnicity). the center of gravity of chinese civilization was on the north china plain, but on the axis between xian and kaifeng, not further north in beijing. and a major secondary axis was in the yangtze river valley, evidenced by the fact that nanjing and yangzhou have both been capitals of all-china governments.

  67. I should add that in East Asia…the Northern people were always barbarians … So I’m not seeing this theory holding up. 
     
    I’m not arguing, but Michael Hart interprets the same history in support of the same general theory (p 412):  
    Throughout history, most of the instances of people from one region attacking and 
    conquering substantial portions of another region have involved “northerners” invading 
    more southerly lands. The European conquests of third-world countries in recent 
    centuries are the most obvious examples of this, but the pattern existed long before 
    modern times. 
     
    China, for example, has never been attacked by any of the populous countries south 
    of it, but it has been repeatedly attacked from the north. Indeed, on two occasions 
    northern invaders conquered all of China. In both cases (the Mongols in the 13th 
    century; the Manchus in the 17th) the northern invaders had much smaller populations 
    than China. Furthermore, within China itself, it was the northerners (under Shih Huang 
    Ti, and the Han dynasty rulers) who first created a unified country by conquering 
    southern China.  
    Sailer cites one paper that also suggests north-to-south intrusion is the historical pattern, presumably facilitated by greater technology at higher latitudes. The trend of increasing technological sophistication with distance from the equator also holds for hunter-gatherers.

  68. Jason: 
     
    I agree with you and Sailer on this North to South intrusion. 
     
    This also occurred inside Europe. Germans and Slavs came from the North East and invaded South into former Roman (Latin and Greek) lands. 
     
    In turn…Romans invaded Greece, Egypt, Carthage. Greeks invaded Egypt. 
     
    Unlike the European examples…Mongols, Turks, and Tungustic tribesmen have never been shown to have higher IQs than Han Chinese in the South or Japanese. 
     
    I would argue this is not as much about IQ as it is about being desperate, that likely compensates for a 2-5 point lapse in IQ. The Northern tribes were highly mobile and far more war-like, as competition for scares resources was more intense on the Eurasian Steppe than on the Chinese plain or in Japan. They developed a aggressive, mobile, fast hitting style of warfare that was not needed in China. 
     
    I would point out that the Mongols had serious problems and loses in Myanmar, Vietnam, Japan, and Java. It appears the Mongols were never very good at fighting where they could not use their horsemanship extensively. Their type of warfare needed wide open grazing lands where they could support their horses, scavenge, and maneuver, feint retreats, etc. 
     
    The Chinese raided to the North of them, but they rarely attempted to colonize anywhere to their far North, beyond the Great Wall. It was not until the Manchu (who were Northern) did the Chinese completely absorb Manchuria and all of Mongolia. They didn’t need to. For what? It would be expensive to hold the territory and there is nothing there…it would and did provide security that is it. 
     
    The Japanese did invade to their North consistently all the way into Siberia, displacing and absorbing occupied lands (although the Russian took those islands back illegally after WWII). 
     
    Egyptians briefly controlled the Levant, but not for very long and the less populated areas of Nubia to their South invaded and controlled them for a short time. 
     
    Despite these examples, I agree that generally invasion has been North to South…and while this may correlate roughly with IQ in many cases, it does not always (as in China and Japan). 
     
    Razib: 
     
    You are definately right…the Y Chromosome (I edited Wiki myself on this) for Han Chinese do not vary much. The variation is on the maternal side. It is well documented in Chinese history that there were many Chinese military movements into the South (all the way into Vietnam) since the Han Dynasty and during the Tang their was a mass exodus of Han Chinese (once again many court officials and soldiers)…it appears they married local woman (related to various South East Asian groups)…which is interesting in the fact that they should have dropped the average Chinese IQ…not increased it. Another mystery for another day.

  69. Furthermore, within China itself, it was the northerners (under Shih Huang Ti, and the Han dynasty rulers) who first created a unified country by conquering southern China.  
     
    this is pretty much misleading. there were no “southern” chinese during this period. china was basically the yellow river plain, and the historic dynamic from the the zhou (1100 BCE) to the tang (600 CE) is one where the elites of northwest (around xian) periphery tended to conquer the rest of the country. form what i recall the rise of the tang was enabled in part by an alliance of the northern military class with the southern based literati. 
     
    also, the north-south conquest of barbarians had a pattern where the barbarians pushed into north china, on occasion to the yangtze, but usually south china was the redoubt of han rulers. the mongols and manchu were exceptions. from this one might infer that south chinese are military more advanced than north chinese, explaining their greater success at resistance to barbarian incursion. of course, that’s obviously a retarded inference for plain reasons, just like the entrenched ming resistance in south china and taiwan might have been enabled by the innate cleverness of the fujianese vis-a-vis the north chinese ;-)

  70. I would argue this is not as much about IQ as it is about being desperate, that likely compensates for a 2-5 point lapse in IQ. The Northern tribes were highly mobile and far more war-like, as competition for scares resources was more intense on the Eurasian Steppe than on the Chinese plain or in Japan. They developed a aggressive, mobile, fast hitting style of warfare that was not needed in China. 
     
    the mongols drove the chinese before them for the same reason that the khalkha mongols had to make an alliance later with the manchus against the dzhungars: civilization softens you. the chinese never held military pursuits in high esteem, perhaps with the exception of the early tang, so soldiers were either temporary levies, convicts, or foreign mercenaries. the consist pattern for northern ‘barbarian’ dynasties was for a few generations of sinicization to ‘soften’ them up and make them easy for other barbarians beyond the limes to take down. the khitan fall before the jurchen in the 12th century is a classic exemplar, but there are plenty others.

  71. Romans invaded Greece, Egypt, Carthage. Greeks invaded Egypt. 
     
    yes, but the byzantine reconquest, and hegemony over portions of the western roman empire from the 6th to the 10th century marks the decline of italian IQ in the face of a greek resurgence!

  72. I don’t really see this working too well in South Asia either.  
     
    The Pashtuns aren’t exactly seen as the harbingers of civilization in modern day Pakistan, for instance.

  73. It appears the Mongols were never very good at fighting where they could not use their horsemanship extensively. Their type of warfare needed wide open grazing lands where they could support their horses, scavenge, and maneuver, feint retreats, etc. 
     
    but recall that china was conquered in large part after kubilai retrained the mongols in chinese siege warfare. the southern song took a while to fall. they also used what they learned to good effect in the west. i think this is clear evidence of high mongol IQ assimilating the useful technology of lower IQ people quickly, who couldn’t adapt appropriately since they were too stupid to figure out how to simultaneously grow enough crops to feed their population and also use it as pasture for horses who could be used in steppe warfare. no horses, and the nomads never lose, even if they can’t win (ask han wu-ti, whose IQ was obviously so low that he couldn’t figure out his armies were not going to be able to defeat the xiongu when they always kept running away).

  74. Razib…too funny, but your points are well taken. 
     
    It appears the normal pattern we see in Europe and Africa don’t seem to apply well in East Asia. Even in Europe is it sketchy. Still one can say that generally Northern people have invaded to their South more than the other way around. 
     
    One can also argue that the Arabs invaded considerably far to their north…all the way to present day Southern France.

  75. It appears the normal pattern we see in Europe and Africa don’t seem to apply well in East Asia. Even in Europe is it sketchy. Still one can say that generally Northern people have invaded to their South more than the other way around. 
     
    yes. the romans are the main exception. the legions which were powerful during the imperial period in making emperors though went from being those of the rhine (trajan), to those of the east (severus), and finally to those of the danube (the emperors of the late 3rd century restoration). that being said, it seems a pre-historic dynamic was a east west movement; the celts and germans for example both came out of central europe, moved to what became france, and fanned out northwest to the british isles and southwest to spain (the celtic and germanic stamp on the british isles remains, that in spain was totally submerged and/or assimilated by the latinate element, perhaps attesting to the greater assimilative power of high IQ latins speakers?). the germans did thrust to the northeast, we don’t remember that as much because they were ethnically cleansed in the 20th century. slavic expansion in eastern europe seems to have been more successful in the north (where non-slavs are the hungarians, who showed up later and assimlated the slavs) than in the south (where greeks, albanians and romanians preserved their identities). 
     
    One can also argue that the Arabs invaded considerably far to their north…all the way to present day Southern France. 
     
    arabs made it to khazaria too, around the latitude of france. the khazars bottled them up at the caucasus though. the ottomans were forces to be reckoned with in the ukraine and poland, though they originally came from the north if you think of their turkic origins. 
     
    in india the north-south dynamic doesn’t work well either. or not as well as you might think. the early empires were often based in bihar, in the center-east (maurya, gupta [though there is circumstantial evidence that ancestrally the gupta were from the west]). before the rise of the muslims there was a period when south indian (chalukya) and bengali (pala) dynasties regularly invaded and fought on the north-central gangetic plain. later the islamic pattern was north-west centric, but this is large part because this was the source of constant new troops and horses.* most indian readers know that the hindu counter-response was eventually led by the central indian marathas. 
     
    * i am pretty sure looking at some of the provenance of the levies that there was regular attrition and assimilation of turks and persians who resettled in india in a manner reminiscent of conquistadors. that’s probably the main reason that the mughals constantly seemed to have need of central asian warriors every generation.

  76. I do know that currently quite a large proportion of China’s entrapanuerial class, even as far north as Beijing, is of southern (Zhejiang, Fujian, etc.) extraction. Even before substanial foreign investment started to flow into China, the southerners were taking advantage of the pro-capitalist economic reforms. Today southern cities like Wenzhou are doing very well and home to numerous large businesses, many of which are oriented around manufacturing. Even in the rural areas, lots of peasants are doing well by setting up their own businesses or sending their working age males to conduct business in other parts of China. Compared to the quickly prospering southerners, it seems like the northerners in the interior and rustbelt are having far more difficulty adjusting to China’s modernization. I think the entrapanuerial culture of the south explains their success, but I wouldn’t neccessarily rule out some type of selection effect…. Let’s also not forget that almost the entire Chinese diaspora is of southern origin too….  
     
    “Throughout history, most of the instances of people from one region attacking and 
    conquering substantial portions of another region have involved “northerners” invading 
    more southerly lands”
     
     
    If the northern climate had a much more difficult living environment than the south, it’d be only logical to expect the northerners to encroach on southern territory…. 
     
    “The European conquests of third-world countries in recent 
    centuries are the most obvious examples of this, but the pattern existed long before 
    modern times.”
     
     
    Well what about the Moorish invasion of Spain? The Ottomans conquering the southeast? The Muslims occuyping the Holy Land? Or the Roman empire’s invasion of northern lands? I wouldn’t disagree that there’s a trend of north invading south, but technologically/economically advanced southern civilizations have done well against northerners at times.  
     
    “China, for example, has never been attacked by any of the populous countries south 
    of it, but it has been repeatedly attacked from the north.”
     
     
    I would imagine that the Himalayan mountains and Tibet acted as a natural barrier to a southern invasion.

  77. I think the entrapanuerial culture of the south explains their success, but I wouldn’t neccessarily rule out some type of selection effect…. Let’s also not forget that almost the entire Chinese diaspora is of southern origin too….  
     
    the fujianese in particular have always been “freelancers” who defied central imperial edicts attempting to control their trade with the outside world. aside from the cantonese in the USA they are the overseas chinese diaspora by and large from what i know. their freedom is partly a function of the fragmentary nature of the local topography and protection via mountains from easy landward access. some of these communities have nearly 1,000 years of cultural fluency with a mercantile outlook hooked into international trade networks, generally with southeast asia.  
     
    that being said, i wouldn’t bet against north china. beijing is doing fine, and the south koreans were an isolated confucian hermit state under chinese hegemony for something like 600 years before their conquest by japan, and they’re doing fine. i wouldn’t be surprised if south chinese lineage networks are just better equipped to handle the ad hoc and somewhat chaotic transition to a capitalist order; but once there’s something of an equilibrium state i think the other groups will catch up.

  78. I would imagine that the Himalayan mountains and Tibet acted as a natural barrier to a southern invasion. 
     
    hart must have been talking about vietnam, nanchao (which was in yunnan), the khmer empire, the thais and what not. notwithstanding the differences in cognitive capital, i think the key here is to think about the comparative advantage of the thai state vs. say the ming empire in the 15th century. it didn’t have any. the thai state was gov. predicated on taxes from peasants ruled by a small civil and military elite. the chinese state was the same (except for possibly a inferior position to the military elite). since china was bigger and more populous there’s just no way that thailand would have been stupid enough to attack china. 
     
    OTOH, nomads had comparative advantage against the chinese state. every single adult male was a potential soldier, and, in terms of conflict the nomads had no fixed capital which the chinese could destroy, while nomads could constantly hit the chinese by disrupting the complex and interlocking systems which kept their society humming just under the malthusian limit. if the chinese won a battle the nomads would just run away, and the mongols had a habit of even switching to hunter-gathering in the deep forest when things got bad. eventually they’d come back out and give it a good college try. at some point they’d break through and succeed (the han ultimate victory against the xiongu wasn’t military, they bribed and assimilated the xiongu elite and so sapped their unity and power). 
     
    this pattern changed in the 18th century. the arrival of guns and cannons increased the power accessible to a semi-modern manchu state. when the dzhungar tribes of western mongolia attempted to recapitulate the standard dynamic whereby they harass and bleed the chinese polity the manchus simply exterminated on the order of 90% of the tribes. guns and cannon made the killing much more efficient. fight smarter, not harder. a large number of dzunghar emigrated to the russian empire and became the kalmyks.  
     
    (p.s., in after tamerlane the author makes the assertion that tamerlane was the turning point between the old style nomad empire and the new style hybrid polities based on guns + horse; the dzunghars were somewhat successful in asserting hegemony across central asia, but they were a pale shadow of the mongols or the first turk empire, suggesting to me i think the shrinking comparative advantage of nomads vis-a-vis the sedentarists)

  79. that being said, i wouldn’t bet against north china. beijing is doing fine, and the south koreans were an isolated confucian hermit state under chinese hegemony for something like 600 years before their conquest by japan, and they’re doing fine. 
     
    China has a long history of advanced civilization and I don’t think that could’ve come about unless there were deep pockets of human capital in the country. So I agree that betting against them might be not be a good idea. 
     
    I’m just a little perplexed as to why Central Asians, Mongols, and some of the other northern ethnicities seem to be really far apart from the Koreans and Japanese.  
     
    i wouldn’t be surprised if south chinese lineage networks are just better equipped to handle the ad hoc and somewhat chaotic transition to a capitalist order; but once there’s something of an equilibrium state i think the other groups will catch up 
     
    I think that’s true to some extent, but it seems that there are quite a few south Chinese that are coming up without any significant support structures too. Lots of peasants in Zhejiang independently transitioned from agriculture to small-scale manufacturing in the opening years of the reforms. Zhejiang peasants are now being held up as a model for the rest of the Chinese peasantry to follow. The same seems to be true of a lot of Fujianese and Cantonese that have gone to diffrent provinces, or even overseas, in search of opportunity. It’s really remarkable how dynamic these people are and how quickly they’ve risen. Though as I said earlier, we definitely can’t discount the role that culture plays in their success. I also think you are right that if you look at historical Chinese migration to SE Asia, lineage played a major role. In my opinion, they benefit from a lot of different factors.

  80.  
     
    I’m just a little perplexed as to why Central Asians, Mongols, and some of the other northern ethnicities seem to be really far apart from the Koreans and Japanese.
     
     
    uh, communism, it fucks you up ;-)

  81. “I’m just a little perplexed as to why Central Asians, Mongols, and some of the other northern ethnicities seem to be really far apart from the Koreans and Japanese.” 
     
    It’s hackneyed and tired, but I really do think Confucianism accounts for a great deal of the difference in mentality and economic performance. 
     
    I suspect that in many respects, the root affinities between the Koreans and Japanese, and their Altaic cousins in Central Asia are quite understated. Korean and Kazakhs often look incredibly similiar. Just a couple of anecdotal examples – I once took a Korean girl to a Uighur restaurant in Shanghai. She was completely unfamiliar with these people, and started in shock when she heard them speak – she was amazed that these long-nosed and hirsute Central Asians were speaking a langauge that sounded so similiar to her own. She even momentarily thought that they were speaking an odd dialect of Korean – I guess in the way that if an English speaker briefly overhears people speaking Flemish, they might mistaken the language for an odd variation of their own.  
     
    I also knew a Kazakh girl who, in spite of being able to perfectly understand Azerbaijanis and Turkmens, was quite convinced that the Kazakhs were closer to the Koreans. This is of course primarily on the grounds of superficial phenotype.  
     
    To me, the Koreans and Japanese are just like any one of the innumerable nations of the north who partook of Yellow River civilization. The only difference is that they have managed to retain and develop distinct identity until the present because of a) a mountainous peninsula and b) an archipaeligo.  
     
    In terms of economic performance and entrepreneurial prowess, however, they of course vary enormously. The track record of the Japanese and South Korean nation-state is obvious. Yet in central Asia, their Kazakh and Kirghiz cousins are considered lazy and backwards compared to the Russians, the Muslim Chinese communities, or other Turkic groups who have a longer history of sedentary life (i.e. Uighurs and Uzbeks).

  82. Incidentally, I am at a loss as to how Confucianism might have increased IQ’s in Korea and Japan. In China, the theory is that the examination system, implemented from the Sui Dynasty onwards, boosted average cognitive ability, since all the spoils and rewards (and thus breeding opportunities) were conferred upon society’s most caable students. But to the best of my knowledge, no such similiar system was ever installed in either Korea or Japan. Instead, Confucian culture was adopted by the pre-existing power holders – feudal barons in Japan and an entrenched class of aristocrats in Korea (yang ban). There was no mass selection mechanism like the empire-wide examination system. I’d be curious if anyone knows otherwise.

  83.  
    I also knew a Kazakh girl who, in spite of being able to perfectly understand Azerbaijanis and Turkmens, was quite convinced that the Kazakhs were closer to the Koreans. This is of course primarily on the grounds of superficial phenotype.
     
     
    the azeris and anatolian turks are turkicized. the kazakhs look more like the original turks, who were extant in mongolia. 
     
    Yet in central Asia, their Kazakh and Kirghiz cousins are considered lazy and backwards compared to the Russians, the Muslim Chinese communities, or other Turkic groups who have a longer history of sedentary life (i.e. Uighurs and Uzbeks). 
     
    also, remember that central asia has a large korean  
    community
    .  
     
    But to the best of my knowledge, no such similiar system was ever installed in either Korea or Japan. Instead, Confucian culture was adopted by the pre-existing power holders – feudal barons in Japan and an entrenched class of aristocrats in Korea (yang ban). There was no mass selection mechanism like the empire-wide examination system. I’d be curious if anyone knows otherwise. 
     
    i think it is important to distinguish korea from japan. korea was ‘more confucian than china.’ japan less so, with the tokugawa period being a time when confucian ideas percolated thoroughly into the country, so rather late.

  84. also, an irony: the most economically advanced south koreans, roman catholics, are the least confucian in their avowed values.

  85. Razib, Arrowsmith, please provide links. 
     
    You do realize that the IQ gap between northern blacks and southern blacks is about 5-7points. That is about half-way the black-white gap. If this were all due to admixture, this would mean that northern blacks are exactly biracial and all southern blacks are fully black. Ridiculous.  
     
    By the way, it’s been shown that most of the blacks at ivies are children of african and caribbean imigrants (ie mostly nigerian, ghanaian and jamaican kids) These kids tend to be even more “black” genetically than the domestic blacks. So clearly, admixture is not helping mixed race blacks that much in the intellectual sphere. 
    Ask the ethiopians – they have the highest caucasian admixture on the continent, yet score in the low 60s – 10pts below the black africa mean.

  86. Eniola,  
     
    A few things. Despite having the largest black populations in the country, Census data on southern states show proportionally smaller mixed race proportions than the rest of the country. 
     
    Slaveholders were most likely to free the offspring they helped create, and those freed were more likely to travel northwards than were those who remained enslaved. On the ellipitical this morning, propitiously enough I read this in Sowell’s Black Rednecks and White Liberals (p42-3): 
     
    As a group, the “free persons of color” also differed from the slaves in racial mixture. As in most of the Western Hemisphere, freed slaves were often the offspring of those who freed them, and the adults freed were more often female than male [mixed/black females are less likely to marry someone more European than themselves than mixed/black males are]. While only 8 percent of slaves met the stringent US Census requirement of half or more white ancestry to be classified as mulatto, 37 percent of the “free persons of color” did. 
     
    Also, anecdotally I find it hard to believe otherwise. I used to live in Redmond, WA and the small black population in Seattle is visibly lighter than the black population in Memphis or Jackson, at least that’s been my experience.

  87. I used to live in Redmond, WA and the small black population in Seattle is visibly lighter than the black population in Memphis or Jackson, at least that’s been my experience. 
     
    I wonder how much the sun might have to do with that – and with other health issues? Is there a notably different health profile among Seattle blacks than, say, Atlanta blacks?

  88. Sorry, I did my best to read through a few days’ worth of comments & didn’t see this mentioned explicitly, but I might’ve missed it. The South is poorer than the North, as one poster alluded to. Poor people score lower on IQ tests than do wealthier people. I do not think the comment “climate precedes the other three variables in causality” applies as neatly to the issue of wealth as it does to the other three variables, again, as alluded to earlier, the South was poorer than the North before the Civil War because it was less industrialized, lost the Civil War because it was less industrialized, & continues to be less industrialized to this day. Whether this itself is due to the climate seems less clear – reliance on slave labor can’t exactly be a spark for achievement. 
     
    I think it would be interesting to account for wealth in the analysis. If it gives the same basic results, it’s not particularly informative (we’re still stuck at hot weather makes you stupid vs. hot weather makes you poor – and poor is essentially stupid & vice versa, if you’ll pardon my gross generalizations). If it is different, in that areas of the South with comparable levels of wealth to the North have similar IQs to the North, then the hypothesis that hot weather makes dimwits is shot.

  89. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8JDD-4R41S55-12&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=53a028b7aea1f33b0a025060162a5709#sc3.1 
     
    Population WLS Gene Identity 
    Maywood, Ill. 18.8 ± 1.4 18.2 ± 0.5 
    Detroit 16.3 ± 2.7 16.9 ± 0.8 
    New York 19.8 ± 2.1 20.2 ± 0.2 
    Philadelphia-1 12.7 ± 1.5 12.6 ± 0.0 
    Philadelphia-2 13.8 ± 1.9 13.2 ± 0.3 
    Pittsburgh 20.2 ± 1.6 20.1 ± 0.4 
    Baltimore 15.5 ± 2.6 15.4 ± 0.8 
    Charleston, S.C. 11.6 ± 1.3 12.2 ± 0.2 
    New Orleans 22.5 ± 1.6 22.8 ± 0.5 
    Houston 16.9 ± 1.5 16.6 ± 0.6 
    Jamaica 6.8 ± 1.3 7.4 ± 0.2 
     
    these results aren’t as clear as i recall, so i’ll reduce my p a bit…. 
     
    By the way, it’s been shown that most of the blacks at ivies are children of african and caribbean imigrants 
     
    http://www.gnxp.com/blog/2005/11/diversity-harvard-reminder.php 
     
    n = 170 
     
    Ethnic self-identification of Harvard black students 
     
    Black American, 57.1% 
    Afro-Caribbean, 21.2% 
    African, 13.6% 
    Bi-ethnic or biracial, 25.9%

  90. uh, communism, it fucks you up ;-) 
     
    Well, I think the Koreans in Central Asian and the Soviet Union did fairly well, in comparison, under Communism even with their humble origins. I believe many had good positions in the Communist governments and they economically/professionally compare fairly well to the ethnic Russians. In contrast, the other ethnicities (Uighurs, Hui/Dungan, Kazakhs, Mongols, etc.) in that region haven’t yet transitioned away from the rural agricultural economy to urban properity. So I do think even amongst genetically similar northern ethnicities, there could possibly be some significant variation in human and cognitive capital. I think it’s important to remember that both Korea and Japan were genetically isolated, so selected alleles could’ve more easily spread throughout the populaces. Northern/Central China plains and the steppes are expansive enough that this may have been less likely to have occurred. Of course I would tend to first look at a cultural explanation behind different outcomes.  
     
    I used to live in Redmond, WA and the small black population in Seattle is visibly lighter than the black population in Memphis or Jackson, at least that’s been my experience. 
     
    I know the black populations of Atlanta and Washington D.C. are fairly prosperous in comparison. Does anybody know if they phenotypically differ from the black mean?  
     
    I’ll note that the African population in the U.S. seems to be very well educated. Just read this: 
     
    http://en.wikipedia.org/wiki/African_immigration_to_the_United_States 
     
    In an analysis of Census Bureau data by the Journal of Blacks in higher education, African immigrants to the United States were found more likely to be college educated than any other immigrant group. African immigrants to the U.S. are also more highly educated than any other native-born ethnic group including white Americans. Some 48.9 percent of all African immigrants hold a college diploma. This is slightly more than the percentage of Asian immigrants to the U.S., nearly double the rate of native-born white Americans, and nearly four times the rate of native-born African Americans.[6] 
     
    In 1997, 19.4 percent of all adult African immigrants in the United States held a graduate degree, compared to 8.1 percent of adult whites and 3.8 percent of adult blacks in the United States, respectively 

  91. In the Southern tip of America, IQ weakens with higher latitudes. The cold theory is nonsense.

  92. I think it’s important to remember that both Korea and Japan were genetically isolated, so selected alleles could’ve more easily spread throughout the populaces. 
     
    japan more than korea. water barriers make a HUGE different in preventing gene flow.

  93. Well, I think the Koreans in Central Asian and the Soviet Union did fairly well, in comparison, under Communism even with their humble origins. I believe many had good positions in the Communist governments and they economically/professionally compare fairly well to the ethnic Russians. 
     
    Do you remember where you read about this? I’d like to look into it.

  94. they’re called koryo-saram if you want to google ‘em….

  95. http://ci.nii.ac.jp/naid/110003106435/en/ 
     
    Most Koreans residing in Central Asia came there not by choice but as a result of political forces beyond their control. The third section will define some specific features of Korean social structure and economic trends, with a special emphasis on the Republic of Kazakhstan. Through hard work, the Koreans have managed to improve their situation greatly. They have educated themselves, and adapted to urban, modern lifestyles, while paying the price with loss of both language and culture.  
     
    http://www.orient.su.se/centralasia/FocasWien.html 
     
    The Koreans in the former Soviet Central Asia were generally regarded as a well assimilated, well educated and well-to-do minority. Their adjustment and assimilation to Soviet standards may have been due not only to their ?Confucian? industriousness but also to several decades of inaccessibility to their own history and isolation from any deeper contact with contemporary Korean society and culture. After the disintegration of the Soviet Union, conditions have changed radically. New details about the former Soviet Koreans in Central Asia have become known through documents which were formerly not accessible for study and publication.  
     
    I recall reading somewhere that quite a few Koreans were prominent in the Communist hierarchy too…

  96. Razib, 
    Ethnic self-identification of Harvard black students 
     
    The children of african and caribbean immigrants would generally self identify as African-american being that they are US citizens. If not, they would not qualify for affirmative action. Those reports greatly understate their numbers – this nytimes article puts their numbers at ivies at about 66% 
     
    http://query.nytimes.com/gst/fullpage.html?res=9F03E6DD1E39F937A15755C0A9629C8B63 
     
    You blogged on this a while back at  
    http://www.gnxp.com/MT2/archives/week_2004_06_20.html 
     
    June 24th 
     
    McGraw 
    I know the black populations of Atlanta and Washington D.C. are fairly prosperous in comparison. Does anybody know if they phenotypically differ from the black mean?  
     
    Washington DC’s overall black population has a bimodal income distribution. Lots of low income 20% white african americans and lots of 100% black africans. DC has the highest proportion of African Immigrants in the country. Their average family income is significantly higher than the country average.  
    Lots of foreign blacks in Atlanta as well but that is likely not the driver of black prosperity there.

  97. Yeah, I think I remember reading about D.C. having lots of successful African immigrants. Eniola do you have any stats for how the children of African refugees perform in this country?  
     
    I recall reading that black Carribean and African children in the UK tend to perform much closer to the white mean than African-Americans, but I don’t think black Carribeans neccessarily test at high IQs. Perhaps immigrant blacks overperform relative to IQ due to cultural factors……

  98. razib- 
     
    How do you know if the people classified as “White” are really White? It could be that people who consider themselves White in the South, are actually Mestiz, and it is a well-documented fact that Mexicans have lower IQ’s than Whites, on average.

  99. How do you know if the people classified as “White” are really White? It could be that people who consider themselves White in the South, are actually Mestiz, and it is a well-documented fact that Mexicans have lower IQ’s than Whites, on average. 
     
    LOL. lots of mestizos in the south, huh! that explains why mississipi and alabama with all their mestizos significantly lower white IQs relative to texas with its trivial number of lying mestizos! can you do math and figure out the algebra that would explain the weight of hispanics you’d have to have to explain the difference? either you can, and are lazy, or you can’t. an ideal comment would actually show the proportion of latinos which you would need to depress IQs instead of asking a skeptical question which requires zero effort (note that some of the plots specifically bracketed out non-hispanic whites). also, the methods were those of audacious epigone and i recall his regression *predicted* the IQs of whites. additionally, razib (me) did not write the post. the comments would also indicate that razib did not write the post, if you read them closely
     
    finally, my follow up post where i used the GSS for english & welsh, irish and germans and excluded hispanics showed the same pattern. of course, someone like you is liable to claim that a bunch of hispanics in the south lied and pretended they were non-hispanic. *shrug*

  100. Is this thing still going? Yikes, Razib, you have greater tolerance for idiocy than I do. 
     
    I’m pretty sure I said that climate affected IQ, etc. for Whites. Like I said, once you go international, you have the problem of selection adapting people to their environment. Take Asian-Americans, who are free to move around, and see what their IQs look like as a function of heat — I haven’t done it, but that’d be better than seeing which parts of China are more developed. 
     
    Any takers on the bet that Asian-Ams in colder states will be smarter than those in hotter states? 
     
    South America is a counterpoint, admittedly using the same non-ideal method as above. Obviously true for Whites, who inhabit the colder regions. But also true for the indigenous — the most advanced were the Incas, and they lived in a colder mountain climate. I think Inductivist or Audacious Epigone did estimates of non-White Latin American IQ, and Peru came out higher than other groups. 
     
    In the Southern tip of America, IQ weakens with higher latitudes. The cold theory is nonsense. 
     
    Dumbass commenters, dime a dozen. I measured average annual heat, not latitude — the former is real, the latter is a construct. Do a correlational analysis, report the p-values, then I’ll believe your stupid little remark.

  101. Yikes, Razib, you have greater tolerance for idiocy than I do. 
     
    hm. perhaps. the thread will close around the 1st of august automatically, so no worries. you can close it early if you want, 99% of the value has already been extracted i think.

  102. Singapore’s success depends a lot on a cool indoor climate and the (relative) absence of bugs. Lee Kuan Yew embraced air conditioning and cleared out the swamp lands in Singapore. All work places and schools are climate controlled. The same is true in most places in hot and humid Asia where high IQ work is being done. Without air conditioning, they are toast.

  103. I’m just a little perplexed as to why Central Asians, Mongols, and some of the other northern ethnicities seem to be really far apart from the Koreans and Japanese.  
    —————————- 
    I’ve read that alcoholism is very widespread in Mongolia–this could certainly have a devastating effect on a civilization.  
    http://www.hartford-hwp.com/archives/55/507.html 
    http://news.bbc.co.uk/2/hi/asia-pacific/3138806.stm

  104. Equivalently, you’re saying that low-latitude dwellers are genetically smarter than they appear, while Canadians, northern Europeans, Eskimos and so on are genetically dumber than they appear. 
     
    That’s an interesting hypothesis, and also an appealing one if you happen to be a fan of Mediterraneans, browns, etc.

  105. Any takers on the bet that Asian-Ams in colder states will be smarter than those in hotter states? 
     
    Based on GSS: The sample of Asians is small, so I combined seven regions into “North” and “South” (but left the Mountain and Pacific regions out since they range north to south). Combining Chinese- and Japanese-Americans born here, the North mean IQ is 103.8; the South is 98.0 (N = 18). To beef up the sorry N a bit I added in Filipinos: North mean becomes 101.0, and the South becomes 96.8. N is still only 25.

  106. We can assume that IQ is normally distributed among Northern and Southern Asian-Ams, since it typically is. Ditto for the variance being the same in the two groups. A t-test doesn’t need that large of a sample size if these things are true, and especially if the true difference is noticeable — which it certainly is in the case of Whites (I didn’t regroup the states by region, but by inspection, looks like 3 or 4 IQ points). 
     
    So even with that small sample size, we can tell that the two groups don’t have the same average IQ.

  107. Correct me if I’m wrong then, but wouldn’t the same patterns holding true for Asian-Americans along a North-South gradient make the hypothesis that it’s pathogenically caused somewhat problematic? Asian-Americans didn’t have much of a population outside of California, the Pacific Northwest and Chicago and New York until well after the advent of the air-con, treated water and nation-wide economy of scale food distribution. Add to that they mostly habitate urban areas with less insect vectors to boot. 
     
    Also it’s easy to handwave a small sample size if one already believes such things to be true, but if one is still dubious, well then… 
    I’m going to be looking at it a bit closer. My non-mathematical mind needs more time to actually crank the data myself.

  108. your being silly. this is pointless till you normalize for all other possible variables. 
    * there are more small states in the north, smaller states get more per-capita funding from the federal government. 
    * population is more urbanized in the north then the south, that might have some effect. 
    * perhaps you should normalize for income level also.

  109. HSwerdfe — are you the moron who emailed me saying I should normalize for income? That reminds me of a joke Steve Sailer tells: African-Americans are no taller than Asian-Americans, when you normalize for the length of their inseam. 
     
    No shit — once you remove lots of variance in one variable (e.g., height varying a lot less for men who wear a given inseam), then the other variables have less variance to account for. 
     
    It’s a standard smokescreen — normalize for income, level of education, number of books in the house, etc., and magically anything correlated to IQ no longer correlates with it. 
     
    Spike — it’s a standard result from statistics. It takes balls to pose a mathematical objection when one doesn’t know the mathematics. Take a simple case — how big of a sample size would you need to tell that men are taller than women on average? Probably 5 of each sex would do.

  110. Agnostic: 
     
    Hence my saying I’m going to look closer at it. I never dismiss anything with a reasonable amount of data and a good train of logic out of hand, but nor do I accept rather outstanding claims on such without a decent amount of rumination either on the train of thought. I do think one of the problems with some conclusions put for here by some posters is the conflation of simple claims with outstanding claims. In other words, I do think that saying this and statistical inferrence of height by gender from a small sample size, particularly given the hypothesis as to why it may be so is not just apples and oranges, but apples and orangutangs! 
     
    Also, I may not be the best with data-crunching, but I can do it if I put my mind to it over a period of time. So, it’s not that “one doesn’t know the mathematics”; I have other intellectual strengths, if I may be so bold. 
     
    Of course, if it’s far easier to dismiss the objections of anyone who’s not as adept as you are in your strengths out of hand, far be it from me to suggest that there may be the loss of something valuable, especially since my primary objections have very little to do with math and more to do with areas in which I’m stronger (scroll upwards to find them again if you so desire, though Razib has provided a good counterpoint to one of them which has partially satiated me). It’s just I’ve always valued outside analysis and criticism, as a counterpoint to my own weaknesses as a thinker. If I didn’t, well then, I wouldn’t be here talking about h/bd as a person who became convinced of it’s merit, right? That’s just me, though. If you’re really convinced in all your conclusions and the weightlessness of outside objections, then good for you. Why, I would venture that you have far more testicular fortitude than you grant me!

  111. What about the brilliant Tamils? How does one explain them! The Tamils are all in all a very successful group, smart, charming and rich. 
    Yet, they come from way down south, and they got more heat than North Indians.

  112. Agnostic, 
     
    Yeah, the thread is still alive. Much as I dig the stuff you write on how to get teenage girls and why girls in their twenties should act as though they were still teenagers, this is even better. 
     
    Re: Peruvians, it’s from a post measuring immigrant performance by six factors: % using one or more welfare programs, % self-employed, % without health insurance, % with less than a high school education, % with a bachelor’s and beyond, and the % in poverty. Peruvians came out second among Latin American immigrants, behind only Colombia.

  113. Re: Peruvians, it’s from a post measuring immigrant performance by six factors: % using one or more welfare programs, % self-employed, % without health insurance, % with less than a high school education, % with a bachelor’s and beyond, and the % in poverty. Peruvians came out second among Latin American immigrants, behind only Colombia. 
     
    My results are similar for the educational attainment of Hispanic Americans: Peruvians were 4th out of 21 groups–only Argentineans, Chileans, and Venezuelans were higher.

  114. Much as I dig the stuff you write on how to get teenage girls and why girls in their twenties should act as though they were still teenagers, this is even better. 
     
    I consider these posts as a kind of Pascal’s Wager, just in case God reads my personal blog.

  115. Inductivist, 
     
    Immigrants from Chile and Argentina weren’t included in the analysis I did due to small numbers. I suspect they’d come out #1 and #2 among Hispanic senders if they were.

  116. This debate is leading nowhere because you are all thinking within the box. Chinese and mongols, Scandinavians and Mediterraneans, etc. But take America as a continent before Columbus. It is a vertical piece of land going from north pole to south pole. The Southern end people, the Onas and Yanaconas, were – according to Darwin and other scientific people who met them before they were exterminated – the most primitive people on Earth, going around naked and feeding on rotten fish. The pattern of occupation, if there is one, seems to be: from the high valleys to the low lands. Mexico City (Tenochitlan) was (is) in a high plateau and ruled the whole region.  
     
    And the reindeer people in the north, the Lapps, never invaded Gothland in the South.  
     
    Therefore geography seems unrelated to Ghenghis Khanness.

  117. Oh come on, surely no one on GNXP buys that rubbish about peaceful indigenous tribes who’d neeeever hurt anyone? Saamis have never had the numbers to wage actual war on southerners, but northern nomads are the best for hit and run. You don’t think they ever used that opportunity? Ha. 
     
    Goddamn Saami propaganda. 
     
    the most primitive people on Earth, going around naked and feeding on rotten fish. 
     
    So I guess today it’s a competition between Finns and Swedes. We do the naked, they do the rotten fish…

  118. Oh come on, surely no one on GNXP buys that rubbish about peaceful indigenous tribes who’d neeeever hurt anyone?  
     
    I do! I’m a product of the American university system, and I believe everything I was told in my required anthropology, sociology, and psychology courses! Why, indigenous peoples were living in a harmonious, peaceful state with nature before the arrival of those bad Europeans. It was all similar to one giant Grateful Dead concert! I read somewhere that the Mohawks invented tie-dye, and the Europeans gave the Mohawks something like $24 dollars worth of plastic beads for the trademark rights!

  119. Why, indigenous peoples were living in a harmonious, peaceful state with nature before the arrival of those bad Europeans. 
     
    Of course. According to my daughter (a sociology major) all the badness in the world comes from evil European colonialism. Before that, the world was a paradise with no fighting or war or violence or disease.

  120. Is there anything out there about brain-generated heat and a possible climate related limiting effect? 
    Is there some point where the brain limits itself if it reaches a higher temperature? Would a culture that values innovation find ways around this?

  121. Gosh, is this thread still going? Maybe we can shoot for one of those records.

  122. I do! I’m a product of the American university system, and I believe everything I was told in my required anthropology, sociology, and psychology courses! Why, indigenous peoples were living in a harmonious, peaceful state with nature before the arrival of those bad Europeans. It was all similar to one giant Grateful Dead concert! I read somewhere that the Mohawks invented tie-dye, and the Europeans gave the Mohawks something like $24 dollars worth of plastic beads for the trademark rights! 
     
    Is there any Western country whose education system that teaches proper, scientific-method, non-bullshit sociology?

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