Rice farming and gene-culture coevolution

 

Why didn’t alcohol intolerance evolve the same way in China as it did in southern Europe? One reason was that the Chinese have a long tradition of boiling water for drinking. So they didn’t need wine as a safe, pathogen-free alternative to water. Facial flushing, before and after (Wikicommons, Brooks et al. 2009)

 

 

In a study of 1,162 Han Chinese, a team led by Thomas Talhelm (2014) found certain psychological differences between Chinese from rice-farming regions and those from wheat-farming regions. The latter tended to be more individualistic, more analytic in their thinking, and less likely to make a big distinction between friends and strangers. Interestingly, these findings were no less true for subjects who had no connection to farming of either sort.

 

Talhelm et al. (2014) attributed these psychological differences to differences between rice farming and wheat farming:

 

The two biggest differences between farming rice and wheat are irrigation and labor. Because rice paddies need standing water, people in rice regions build elaborate irrigation systems that require farmers to cooperate. In irrigation networks, one family's water use can affect their neighbors, so rice farmers have to coordinate their water use. Irrigation networks also require many hours each year to build, dredge, and drain—a burden that often falls on villages, not isolated individuals. 

 

In comparison, wheat is easier to grow. Wheat does not need to be irrigated, so wheat farmers can rely on rainfall, which they do not coordinate with their neighbors. Planting and harvesting wheat certainly takes work, but only half as much as rice. The lighter burden means farmers can look after their own plots without relying as much on their neighbors. (Talhelm et al., 2014)

 

The term “gene-culture coevolution” isn’t mentioned, but it did cross my mind when I read that paper, and I suspect it also crossed Talhelm’s. Did rice farming favor the success of individuals who were better at rice farming? And were those individuals sometimes better because they had certain mental and behavioral tendencies?

 

That hypothesis has recently been tested in a study by Chen Zhu and other co-researchers, including Thomas Talhelm:

 

Here, we report evidence that the advent of rice domestication and cultivation may have shaped humans not only culturally but also genetically. Leveraging recent findings from molecular genetics, we construct a number of polygenic scores (PGSs) of behavioural traits and examine their associations with rice cultivation based on a sample of 4101 individuals recently collected from mainland China. (Zhu et al. 2021)

 

The polygenic scores were for height, body mass index, depression, time discounting, age at first birth, educational attainment, risk preference, and tolerance for alcohol (as measured by the ability to break it down via two enzymes: alcohol dehydrogenase and aldehyde dehydrogenase). For each mental or behavioral trait, the polygenic scores were compared with the subjects’ county of birth, specifically the county’s proportion of farmland devoted to rice paddies.

 

The trait/county correlations were then investigated for possible confounds. Because rice farming is more common in southern China, there may be confounds with latitude, temperature, certain minority groups, and so on. After controlling for these confounds, the authors found that two negative correlations remained significant: (1) age at first birth and (2) tolerance for alcohol, as measured by the ability to produce aldehyde dehydrogenase.

 

It seems, then, that people from rice-farming regions are more likely to feel sick after drinking alcohol, and that women are more likely to begin having children at a younger age. Let’s take a closer look at both findings:

 

Age at first birth

 

Rice-farming regions are associated with a younger age at first birth. Historically, rice was far more labor-intensive than wheat. The labor demands were so high that a husband and wife could not farm a large enough plot to support their family through their labor alone. Life expectancy may have also been shorter in rice-farming regions than in wheat-farming ones, with the result that the reproductive schedule was shifted toward younger ages wherever rice was primarily grown (Zhu et al. 2021). 

 

Alcohol tolerance

 

Rice-farming regions are associated with defective enzymes for alcohol tolerance. This seems to be much truer for aldehyde dehydrogenase than for alcohol dehydrogenase. Both defects reduce clearance of alcohol by the liver, but the first one has a stronger effect. In about 36% of East Asians, it causes facial flushing, nausea, and tachycardia after alcohol consumption. Not surprisingly, carriers appear to suffer less from alcoholism and alcohol-related liver disease (Brooks et al. 2009; SNPedia 2020).

 

Zhu et al. (2021) argue that selection against alcohol tolerance was stronger in rice-farming regions because rice farmers had surplus rice for wine production at an earlier date. This argument assumes that alcohol consumption was always maladaptive: once it became common, selection immediately favored individuals who couldn’t tolerate alcohol. Yet we know that alcohol consumption used to be adaptive in many parts of the world, such as southern Europe, where fermented beverages were safer to drink than water because they had no water-borne pathogens.

 

I would argue that selection against alcohol tolerance began in China when fermented beverages, notably rice wine, ceased to be the best alternative to water. Consumption of rice wine was widespread at first but later gave way to consumption of boiled water, particularly in the form of tea, during the Tang dynasty (7th to 10th centuries). There then followed a period of relative abstinence until the 19th century:

 

Following the Yangtze's incorporation into the Chinese state during the Qin dynasty, beer progressively disappeared from use over the course of the Han dynasty in favor of the stronger huangjiu and the rice wines of the southern Chinese. […] The Dutch historian Frank Dikötter describes the period between the Han and Tang dynasties as a "golden age" for alcohol […] The "rise of a tea culture during the Tang was a significant shift away from heavier patterns of intoxication".  […] Wine was reintroduced to China at Macao by Portuguese traders and missionaries, who produced small batches for communion. […] The production and its effect was minor, prior to the opening of the country by the 19th-century First and Second Opium Wars, after which European alcoholic beverages and methods of alcohol production were introduced throughout China. (Wikipedia 2022)

 

With the replacement of rice wine by tea during the Tang Dynasty, people no longer had the same need for enzymes that break down alcohol. The advantages of alcohol, in terms of preventing water-borne diseases, became outweighed by the disadvantages, in terms of alcoholism and alcohol-related diseases.

 

Thus began a long Chinese tradition of drinking hot water (Ye 2017). Rice wine, with its high alcohol content of 18-25%, became seen not only as unnecessary but also as problematic, due to the risk of alcoholism and alcohol-related diseases. Rice-farming regions may have therefore experienced a steeper decline in alcohol consumption during China’s long period of relative abstinence between the 7th and 19th centuries. If so, alcohol intolerance would be a recent evolutionary development in China’s rice-farming regions.

 

Elsewhere, as in southern Europe, people continued to drink wine as a safe alternative to water. There was thus selection for willingness to consume alcohol, but not to excess.

 

What about individualism?

 

Why didn’t Zhu’s research team look at genetic markers for individualism? Wasn’t that the main behavioral difference between rice-farming and wheat-farming regions in Talhelm’s study? The oversight is all the more puzzling because Talhelm was one of Zhu’s co-authors.

 

There is, in fact, a genetic marker for individualism: the short allele of 5-HTTLPR (Chiao and Blizinsky 2010; Schroeder et al., 2016). In addition, I would look at genetic markers for the propensity to identify social norms, to comply with them, and to ensure that others comply (Frost 2020).

 

What about cognitive ability and future orientation?

 

Zhu et al. (2021) also looked at cognitive ability (as measured by educational attainment) and future orientation (as measured, inversely, by time discounting). Cognitive ability and future orientation are both high in East Asians, but neither seem to differ significantly between Chinese from rice-farming regions and those from wheat-farming regions. In the initial results (i.e., before they were controlled for possible confounds), the first group was less future-oriented than the second, but this difference seems to be due to southern Chinese being less future-oriented than northern Chinese.

 

Things are rarely simple. No single theory can explain all the mental and behavioral differences that exist within our species. Yes, some researchers have proposed various unified theories of human biodiversity: r/k selection, selection in tropical vs. northern environments, and selection among trading vs. non-trading peoples, etc.  Each of them explains part of the picture, but none explains the whole picture.

 

There will never be a unified theory of human biodiversity, other than Darwin’s theory of evolution by natural selection. Human nature is shaped by many different selection pressures with many different causes.

 

References

 

Brooks, P.J., M-A. Enoch, D. Goldman, T-K Li, and A. Yokoyama. (2009). The Alcohol Flushing Response: An Unrecognized Risk Factor for Esophageal Cancer from Alcohol Consumption. PLoS Med 6(3): e1000050. https://doi.org/10.1371/journal.pmed.1000050  

 

Chiao, J. Y., & K.D. Blizinsky. (2010). Culture-gene coevolution of individualism-collectivism and the serotonin transporter gene. Proceedings of the Royal Society B: Biological Sciences 277: 529-537. https://doi.org/10.1098/rspb.2009.1650   

 

Frost, P. (2014). Rice farming and gene-culture co-evolution. Evo and Proud, May 31

https://evoandproud.blogspot.com/2014/05/   

 

Frost, P. (2020). The large society problem in Northwest Europe and East Asia. Advances in Anthropology 10(3): 214-134.

https://doi.org/10.4236/aa.2020.103012    

 

SNPedia (2020). rs671

https://www.snpedia.com/index.php/Rs671   

 

Talhelm, T., X. Zhang, S. Oishi, C. Shimin, D. Duan, X. Lan, and S. Kitayama. (2014). Large-scale psychological differences within China explained by rice versus wheat agriculture. Science 344: 603-607.

https://doi.org/10.1126/science.1246850   

 

Wikipedia (2022). Alcoholic drinks in China.

https://en.wikipedia.org/wiki/Alcoholic_drinks_in_China

 

Ye, F. (2017). The History of Drinking Hot Water in China (from a Cold-Water-Drinking Chinese). Radii, June 23

https://radiichina.com/the-history-of-drinking-hot-water-in-china/   

 

Zhu, C., T. Talhelm, Y. Li, G. Chen, J. Zhu, and J. Wang. (2021). Relationship between rice farming and polygenic scores potentially linked to agriculture in China. Royal Society Open Science 8(8):210382. https://dx.doi.org/10.1098%2Frsos.210382   

Coevolution with the plague

Houses being burned during an outbreak of pneumonic plague in China (Wikicommons). In China, large urban populations coevolved with deadly pulmonary infections, like tuberculosis, pneumonia, and pneumonic plague. Because resistance was boosted by regular exposure to normally mild infections by coronaviruses, there was natural selection for more susceptibility to them.



Two posts ago I argued that coronaviruses have coevolved with the Chinese population, to the point of developing a commensal relationship. A few points:

-  Such viruses include the common cold and are normally mild in their effects.

- Repeated coronaviral infections of lung tissue may actually help increase resistance to more serious pulmonary infections, like tuberculosis, pneumonia, and the Spanish flu of 1918—which curiously spared China. 

- Chinese lung tissue would thus facilitate coronaviral infections as a sort of routine vaccination. 

- If this is true, modern medicine has inadvertently made the Chinese population particularly vulnerable to deadly diseases like the Wuhan coronavirus by reducing the prevalence of milder pulmonary infections.


The examples of herpesvirus and cytomegalovirus

This cross-immunity is seen with other viruses. In mice, gammaherpesvirus 68 (similar to Epstein-Barr virus) provides immunity against much deadlier bacterial pathogens: Listeria monocytogenes; Yersinia pestis, which has caused plagues like the Black Death; and Mycobacterium tuberculosis, i.e. tuberculosis (Barton et al. 2007; Miller et al. 2019). Infection with cytomegalovirus likewise immunizes against Listeria monocytogenes and Yersinia pestis (Barton et al. 2007).

Quite a few writers have argued that many common pathogens are actually allies that help us fight more serious diseases: 

The microbial communities of humans are characteristic and complex mixtures of microorganisms that have co-evolved with their human hosts. The species that make up these communities vary between hosts as a result of restricted migration of microorganisms between hosts and strong ecological interactions within hosts, as well as host variability in terms of diet, genotype and colonization history. The shared evolutionary fate of humans and their symbiotic bacteria has selected for mutualistic interactions that are essential for human health, and ecological or genetic changes that uncouple this shared fate can result in disease. (Dethlefsen et al. 2007)

So it’s possible that humans have coevolved with mildly acting viruses as a means to ward off pathogens that cause more serious pulmonary infections, such as pneumonic plague and tuberculosis. Moreover, this coevolution may have taken different forms in different human populations, a possibility raised by Miller et al. (2019): "our results suggest human γHV-infection may be an important but unrecognized factor which modifies TB outcome, particularly in high TB burden countries where most children acquire EBV [Epstein-Barr virus] by 3 years of age."

Comas et al. (2013) describe the evolution of tuberculosis in our species and how it became more common in certain human environments, particularly "crowded" ones:

Crowd diseases are generally highly virulent and depend on high host population densities to maximize pathogen transmission and reduce the risk of pathogen extinction through exhaustion of susceptible hosts. Many crowd diseases emerged during the Neolithic Demographic Transition (NDT) starting around ten thousand years ago (kya), as the development of animal domestication increased the likelihood of zoonotic transfer of novel pathogens to humans, and agricultural innovations supported increased population densities that helped sustain the infectious cycle. The marked expansion of MTBC [Mycobacterium tuberculosis complex] during the NTD, but not during earlier human expansion events, suggests that the success of this pathogen was primarily driven by increases in human host density, which is typical of crowd diseases.

Perry et al. (2010) have shown that Helicobacter pylori, a bacterium that lives in the stomach lining, greatly reduces the risk of tuberculosis infection. Again, less serious infections help ward off much more serious ones, like tuberculosis:

Why only 10% of infected individuals succumb to tuberculosis remains one of the most vexing public health questions—one which the one-pathogen-one-disease paradigm is ill-equipped to answer. While preliminary, our work suggests that one factor contributing to the clinical outcome of TB infection may be a concurrent chronic infection. The hypothesis that the human microbiome has evolved to provide context-specific competitive risk advantages to the host also raises the intriguing possibility that our microbiota can be manipulated to modulate disease risk from M. tuberculosis, as well as other common human pathogens. (Perry et al. 2010)

Have the Chinese coevolved with coronaviruses?

Common viral infections may have a similar protective effect. If we go back to the Barton et al. study, we find that it was criticized by Yager et al. (2009) on the grounds that the cross-immunity seems to last only five months after acute infection. To benefit from this cross-immunity, lung tissue should therefore be regularly infected with a virus whose adverse effects are both mild and temporary, like most coronaviruses.

Are the Chinese innately more susceptible to coronaviruses? Attention has focused on a study by Zhao et al. (2020), who, using lung tissue from several donors, studied a receptor, ACE2, that acts as the point of entry for some coronaviruses, including the one responsible for the outbreak in Wuhan. They found that the receptor was concentrated in certain cells and that the number of such cells in lung tissue was five times greater in the Asian donor. Yes, there was only one Chinese donor, but the chances are very low that the same normal distribution would produce such an extreme outlier.

This finding is also consistent with those of previous studies. Cheng et al. (2007) looked at other receptors for viral infections and found differences between Chinese and other human populations. In the specific case of pulmonary diseases, Seitz et al. (2012) studied the prevalence of bronchiectasis in the United States and found a prevalence 2.5 to 3.9 times higher among Asian Americans than among Euro Americans or African Americans. Kwak et al. (2010) likewise found a high prevalence of bronchiectasis in Korean adults.

Since my last post on the subject, two more studies have come out.


The Cai study

Cai (2020) failed to find significant differences in ACE2 receptor gene expression between Asian and Caucasian lung tissue but did find an interaction between smoking history and ethnicity: "we found ACE2 is most actively expressed in AT2-reformed cells in former Asian smokers but not in Caucasian current smokers and African American non-smokers." However, this difference wasn’t significant. 

This study has an adequate sample size (n=345) but uses a questionable classification by ethnicity. The lung tissue samples were from a U.S. company, Gene Expression Omnibus, which classifies its samples as "Caucasian," "African American," or "Asian." Although most Asian Americans are of East Asian descent, many have roots in Southeast Asia or South Asia. As we will see, there are probably significant differences in the ACE2 receptor even between Asian groups.


The Cao et al. study 

Cao et al. (2020) looked at the different alleles for the ACE2 receptor gene in two databases: the China Metabolic Analytics Project and the 1000 Genomes Project. They found large differences in allele frequencies among human populations, not only between Asians and other human groups but also between different Asian groups. "These data suggested that there was a lack of natural resistant mutations for coronavirus S-protein binding in [some] populations."

Their conclusion more or less sums up current knowledge:

Recent reports of the ACE2 expression analysis in lung tissues from Asian and Caucasian populations are still controversial. The single-cell RNA-seq analysis reported that the Asian donor had much higher ACE2 expression cell ratio than white and African-American donors. In contrast, the ACE2 expression analysis using the RNA-seq and microarray datasets from control lung tissues indicated there were no significant differences between Asian and Caucasian, or male and female. The ACE2-expressing cells are a very small part of cells in lung tissues. The sample size and the purity of ACE2-positive cells in the selected samples would influence the conclusions. Our analysis showed the differences in distribution and AFs [allele frequencies] of eQTLs for ACE2 in different populations, indicating the diversity of ACE2 expression pattern in populations. […] In addition, our data showed the moderate difference in AFs of eQTLs between South Asian and EAS [East Asians], which suggests the potential difference of ACE2 expression in different populations and ethnics in Asia. (Cao et al. 2020)

Conclusion

Without knowing what these alleles actually do, we can only say that the ACE2 receptor has coevolved differently with different human populations and, presumably, different natural and social environments. In particular, crowded environments, with high rates of life-threatening pulmonary infections, notably tuberculosis, pneumonia, and pneumonic plague, should have favored individuals who are more susceptible to infection by coronaviruses. 

Historically, such environments would encompass not only China but also other areas that have long had large urban populations and a correspondingly long coevolution with pulmonary infections. These areas would notably include the Indo-Gangetic Plain in India and the Fertile Crescent of the Middle East.


References

Barton, E.S., D.W. White, J.S. Cathelyn, K.A. Brett-McClellan, M. Engle, M.S. Diamond, V.L. Miller. H.W. Virgin IV. (2007). Herpesvirus latency confers symbiotic protection from bacterial infection. Nature 447:326-9.
https://www.nature.com/articles/nature05762

Cai, G. (2020).  Bulk and single-cell transcriptomics identify tobacco-use disparity in lung gene expression of ACE2, the receptor of 2019-nCov. medRxiv February 17
https://www.medrxiv.org/content/10.1101/2020.02.05.20020107v2

Cao, Y., L. Li, Z. Feng, et al. (2020). Comparative genetic analysis of the novel coronavirus (2019-nCoV/SARS-CoV-2) receptor ACE2 in different populations. Cell Discovery 6: 11.
https://www.nature.com/articles/s41421-020-0147-1

Cheng, P-L, H-L. Eng, M-H. Chou, H-L. You, T-M. Lin, (2007). Genetic polymorphisms of viral infection-associated Toll-like receptors in Chinese population. Translational Research 150(5): 311-318
https://www.sciencedirect.com/science/article/pii/S1931524407000953

Comas, I., M. Coscolla, T. Luo, S. Borrell, K.E. Holt, M. Kato-Maeda, et al. (2013). Out-of-Africa migration and Neolithic coexpansion of Mycobacterium tuberculosis with modern humans. Nature genetics 45(10): 1176-1182.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3800747/

Dethlefsen, L., M. McFall-Ngai, and D. Relman. (2007). An ecological and evolutionary perspective on human-microbe mutualism and disease. Nature 449: 811-818.
https://www.researchgate.net/profile/David_Relman/publication/5902740_Dethlefsen_L_McFall-Ngai_M_Relman_DA_An_ecological_and_evolutionary_perspective_on_human-microbe_mutualism_and_disease_Nature_449_811-818/links/0deec5278790b8a5be000000.pdf

Kwak, H.J., J.Y. Moon, Y.W. Choi, T.H. Kim, J.W. Sohn, H.J. Yoon, D.H. Shin, S.S. Park, and S.H. Kim. (2010). High prevalence of bronchiectasis in adults: analysis of CT findings in a health screening program. Tohoku Journal of Experimental Medicine 222: 237-242.
https://pdfs.semanticscholar.org/dd5d/c5d64f82c84277b74024af0671c8ec070fa6.pdf  

Miller, H. E., K.E. Johnson, V.L. Tarakanova, and R.T. Robinson. (2019). γ-herpesvirus latency attenuates Mycobacterium tuberculosis infection in mice. Tuberculosis (Edinburgh, Scotland) 116: 56-60.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6876742/

Perry, S., B.C. de Jong, J.V. Solnick, M. de la Luz Sanchez, S. Yang, P.L. Lin, et al. (2010). Infection with Helicobacter pylori is associated with protection against tuberculosis. PloS one 5(1), e8804.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2808360/

Seitz, A.E., K.N. Olivier, J. Adjemian, S.M. Holland, and D.R. Prevots. (2012). Trends in bronchiectasis among medicare beneficiaries in the United States, 2000 to 2007. Chest 142(2): 432-439.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3425339/  

Yager, E.J., F.M. Szaba, L.W. Kummer, K.G. Lanzer, C.E. Burkum, S.T. Smiley, and M.A. Blackman. (2009). γ-Herpesvirus-induced protection against bacterial infection is transient. Viral immunology 22(1): 67-72.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2952138/

Zhao, Y., Z. Zhao, Y. Wang, Y. Zhou, Y. Ma, and W. Zuo. (2020). Single-cell RNA expression profiling of ACE2, the putative receptor of Wuhan 2019-nCov. bioRxiv January 26
https://www.biorxiv.org/content/10.1101/2020.01.26.919985v1.full  

A Pandora's box?

Chinese lung tissue seems to be receptive to coronaviruses, perhaps because frequent mild infections stimulate the immune system to protect against more serious pulmonary infections, like pneumonia and tuberculosis. This may be why China escaped the ravages of the Spanish flu in 1918. Have modern measures for public health opened a Pandora's box in China? (Wikipedia – CDC)



Are Chinese people more vulnerable than others to the Wuhan coronavirus? The question is raised by Zhao et al. (2020), who examined lung tissues from several donors and studied a receptor that acts as the point of entry for some coronaviruses, including the ones responsible for the SARS outbreak of 2002-2003 and the ongoing outbreak in Wuhan, China. They found that the receptor was concentrated in cells that promote viral reproduction and transmission. They also found that the number of these cells in lung tissue varied with ethnic origin:

A comparison between eight individual samples demonstrated that the Asian male one has an extremely large number of ACE2-expressing cells in the lung. We also noticed that the only Asian donor (male) has a much higher ACE2-expressing cell ratio than white and African American donors (2.50% vs. 0.47% of all cells). This might explain the observation that the new Coronavirus pandemic and previous SARS-Cov pandemic are concentrated in the Asian area.

This study is a preprint and has not yet been peer-reviewed, a fact highlighted in a notice placed above the online paper:

bioRxiv is receiving many new papers on coronavirus 2019-nCoV. A reminder: these are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information.

I often consult bioRxiv, and this is the first time I've seen such a notice. It's not as if this study has been widely publicized in the mainstream media.

A peer reviewer would make the same criticism that the authors themselves make: the sample size is small. In fact, there was only one Asian in the entire sample. Nevertheless, sampling error cannot easily explain the five-fold difference between the Asian donor and the non-Asian ones. Moreover, this finding is consistent with those of previous studies. Cheng et al. (2007) looked at other receptors for viral infections and found differences between Chinese and other human populations. In the specific case of pulmonary diseases, Seitz et al. (2012) studied the prevalence of bronchiectasis in the United States and found that Asian Americans had a prevalence 2.5 to 3.9 times higher than those of Euro Americans and African Americans. Kwak et al. (2010) similarly found a high prevalence of bronchiectasis in Korean adults.

These ethnic differences should be no surprise. Many pathogens can infect some populations more easily than others. This was shown by a study of the TLR2 polymorphism, which influences resistance to such infections as leprosy, tuberculosis, staphylococcal infections, and sepsis:

Interestingly, recent data have pointed out that TLR2 polymorphisms are associated with disseminated tuberculosis or exert specific effects on susceptibility to certain mycobacterial strains, such as the Beijing strains of Mycobacterium tuberculosis. The Beijing strains have a clear geographical distribution, raising the possibility that human TLR2 has coevolved in various populations depending on the type of infectious pressure in a particular region, similarly to what has been reported for polymorphisms in other innate immune genes such as TLR4 or Mal/TIRAP. (Iona et al. 2012)

The argument here is that an infectious disease will favor the survival and reproduction of those people who are more resistant to it. So, over succeeding generations, the average person will become naturally more resistant. The degree of resistance will vary from one population to another because the incidence of infectious pathogens typically varies from one population to another.

In this case, the average Chinese person seems to be naturally less resistant to coronaviruses. That is a bit surprising. The Chinese have cohabited with various forms of livestock for a long time, longer than most humans, and should have become more resistant to viral infections that jump the species barrier, like the current coronavirus in Wuhan. Yet, here, the reverse is true.

Perhaps we're looking at this coevolution the wrong way. Perhaps coronaviruses usually do more good than harm. Perhaps, over time, there has been selection to make the average Chinese person less resistant to them. This possibility has been explored in a recent paper by Shekhar et al. (2017). Certain viral infections of the respiratory tract seem to help their hosts by boosting resistance to bacterial infections:

Little is known about the interaction of the host with commensal viruses and fungi that inhabit the respiratory system. Latent infection with herpesviruses can lead to opportunistic infections in immunocompromised individuals. Recent findings, however, highlight a new role for these viruses in increasing host resistance to bacterial infections. Infection with herpesviruses in mice results in chronic production of large quantities of IFN-γ and activation of macrophages that confer protection from subsequent infection with Listeria monocytogenes and Yersinia pestis. (Shekhar et al. 2017)

So you periodically come down with a mild flu, and you can better resist more serious pulmonary infections, like pneumonia and tuberculosis. Of course, now and again, the flu might be deadly, like the one in 1918. Interestingly, China was largely unaffected by the Spanish flu pandemic: "in 1918, China was spared from the worst ravages of the pandemic, due to the apparent greater resistance to the virus among the Chinese population compared to other regions of the world" (Wikipedia 2020).

Since then, public hygiene measures have steadily reduced chronic exposure to mild pulmonary infections in the Chinese population. If the Spanish flu struck China today, would the Chinese people be just as unaffected? Is this why the Wuhan outbreak has been so severe?


Conclusion

The Chinese population has developed a commensal relationship with coronaviruses, which are usually mild and seem to prepare the immune system for serious pulmonary infections. Through a process of coevolution, the Chinese have become five times more susceptible to coronaviruses than other human populations. 

Far from being an enemy, these viruses may actually be a friend that plays a valuable immunological role. By creating a cleaner social environment, the Chinese authorities may have unwittingly opened a Pandora's box. 

As for non-Chinese people, it doesn't follow that they will be immune to the new coronavirus, only that they will be less vulnerable.

On a final note, the economic disruption due to the Wuhan outbreak will lead to a contraction in Chinese production, and this contraction will exacerbate the ongoing problem of China's shrinking workforce. There are going to be fewer and more expensive consumer goods on the global market. Ironically, all of this is happening as we enter the 2020s—a decade already predicted to be a time of crisis. 


References

Cheng, P-L, H-L. Eng, M-H. Chou, H-L. You, T-M. Lin, (2007). Genetic polymorphisms of viral infection-associated Toll-like receptors in Chinese population. Translational Research 150(5): 311-318
https://www.sciencedirect.com/science/article/pii/S1931524407000953 

Ioana, M., B. Ferwerda, T. S. Plantinga, M. Stappers, M. Oosting, M. McCall, A. Cimpoeru, F. Burada, N. Panduru, R. Sauerwein, O. Doumbo, J. W. M. van der Meer, R. van Crevel, L. A. B. Joosten, and M. G. Netea. (2012). Different Patterns of Toll-Like Receptor 2 Polymorphisms in Populations of Various Ethnic and Geographic Origins. Infection and Immunity 80(5): 1917-1922
https://iai.asm.org/content/80/5/1917 

Kwak, H.J., J.Y. Moon, Y.W. Choi, T.H. Kim, J.W. Sohn, H.J. Yoon, D.H. Shin, S.S. Park, and S.H. Kim. (2010). High prevalence of bronchiectasis in adults: analysis of CT findings in a health screening program. Tohoku Journal of Experimental Medicine 222: 237-242.
https://pdfs.semanticscholar.org/dd5d/c5d64f82c84277b74024af0671c8ec070fa6.pdf

Seitz, A.E., K.N. Olivier, J. Adjemian, S.M. Holland, and D.R. Prevots. (2012). Trends in bronchiectasis among medicare beneficiaries in the United States, 2000 to 2007. Chest 142(2):432-439.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3425339/

Shekhar, S., K. Schenck, and F. C. Petersen (2017). Exploring Host-Commensal Interactions in the Respiratory Tract. Frontiers in Immunology 8: 1971
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5776090/  

Wikipedia. (2020). Spanish flu
https://en.wikipedia.org/wiki/Spanish_flu 

Zhao, Y., Z. Zhao, Y. Wang, Y. Zhou, Y. Ma, and W. Zuo. (2020). Single-cell RNA expression profiling of ACE2, the putative receptor of Wuhan 2019-nCov. bioRxiv January 26
https://www.biorxiv.org/content/10.1101/2020.01.26.919985v1.full

The 2020s are here

Elderly Shanghai woman practicing tai-chi (Wikipedia – Tom Thai)



Two years ago I wrote about "The Crisis of the 2020s." I argued that this decade would see a worsening confrontation between two world views:

On the one hand, the globalist consensus will continue to radicalize in the core countries of the Western world. On the other hand, a very different consensus will dominate most of central and eastern Europe, with inroads being made into France and Germany. These opposing consensuses will diverge more and more, if only because mutual antagonism will make dialogue impossible. (Frost 2017a)

This confrontation is taking place at a time when the "consensus" no longer seems to be delivering the goods. Economic growth is sluggish not only throughout the West but also in the supposed beneficiaries of globalization—China, in particular. For some, this slowdown means that the current system has failed. For others, it means that the failings of globalization can be resolved only through more globalization.

The Crisis of the 2020s is thus primarily ideological. People are split into opposing camps, and it is far from clear which one will win. While the globalist consensus is losing ground in eastern, central, and southern Europe, it still dominates the western core of the UK, France, and Germany ... as well as North America. The West has lost its manufacturing base but is still culturally dominant. That dominance, not so much in ideas as in the packaging of ideas, is critical to promoting a model of society where people are interchangeable units in a global marketplace.

The ideological crisis will nonetheless be made worse by real-world problems:


China: a shrinking work force

China’s exports will become more expensive as its work force shrinks and grows old. This shrinkage will be worse than expected because the Chinese authorities have been overestimating the country’s fertility rate for almost two decades. The current rate is not 1.6 children per women. In fact, it had already fallen to 1.4 by 2003 and is now probably one child per woman. And this is happening even though the one-child policy is no longer in effect. The fertility rate is even lower among Han Chinese and lower still in the industrialized northeast—where it is down to 0.75 (Frost 2019a; Wang 2018). 

There are already fewer Chinese workers with each passing year, and this decrease will accelerate as the smaller cohorts of the noughts and teens enter the job market. Inevitably, the price of labor will rise. This will be good for China, which needs to reorient away from exports and toward its domestic economy. Western countries, however, will have to be weaned off their dependence on cheap Chinese goods.

Can the same goods be produced elsewhere? Unlikely. None of the alternatives sources of cheap labor have the same worker quality or, just as importantly, worker quantity. In hindsight, China was a lucky find for globalization—a country where the average worker was not only inexpensive but also intelligent and disciplined.

Western consumers are already cash-strapped, with most of them living from pay check to pay check. Where will they get the money to pay for a steep increase in the price of consumer goods?


The global food crisis

The Arab Spring was triggered by a surge in food prices. That surge was no fluke. We are reaching the end of a long increase in food production, a “green revolution” made possible by large-scale monoculture, intensive plowing, and heavy use of chemical fertilizers. That increase has come at a price, particularly degradation of soil fertility. Further increases will be modest and will require a more sustainable model of agriculture, as well as more investment in automation and robotization. Unfortunately, such changes, especially the latter, are impeded by the current heavy reliance on cheap migrant labor.

Agribusiness, particularly in the U.S., has become a conservative force that will stubbornly resist change. Like the culture industry, it will push for more of the same.


The decline of high-trust societies

The evolution of social complexity is far from easy. One of the main challenges has been the creation of large societies in which economic transactions take place mostly between unrelated individuals. Such societies are impossible in most of the world because of the high level of mistrust between unrelated individuals. Each transaction has to be checked and double-checked for lying, cheating, and outright theft. Many transactions never take place because they just aren't cost-effective.

This obstacle has been overcome in northwest Europe and East Asia. In both areas, the solution is behavioral and psychological. Northwest Europeans are more individualistic, less loyal to kin, and more trusting of strangers. Because they attach less importance to kinship, they have been able to build large, functioning societies on the basis of “impersonal prosociality,” i.e., willingness to obey universal social rules, affective empathy toward nonkin, and feelings of guilt for unwitnessed rule breaking (Frost 2017b; Frost 2019b; Schulz et al. 2019). East Asians are less individualistic but just as willing to obey universal rules, which are enforced more by shame than by guilt. Empathy is also at a high level, but less differentiated between affective and cognitive empathy:

The main difference is in the relationship between self and society. Whereas a greater sense of self has helped Northwest Europeans to transcend the limitations of kinship and, thus, build larger societies, East Asians have relied on a lesser sense of self to create a web of interdependence that extends beyond close kin. (Frost 2015)

Northwest Europeans and East Asians are now in steep demographic decline. Inevitably, less wealth will be created. I say "inevitably" because those two groups produce most of the world’s wealth. When they go, most of the wealth will go too. This is not a problem we can resolve by passing laws or changing the school curriculum. To some extent, we could force people to adopt the behaviors of a high-trust society, but that would take time and will. And we don't have much of either.


A name with a nice ring to it

When I wrote that post two years ago I settled on the name "Crisis of the 2020s." It had a nice ring to it. While doing research for this post, I googled the same name ... and got over 56,000 hits. The oldest hit seems to be a 2011 article: "Global Aging and the Crisis of the 2020s." I hadn't read it previously, but it points to the same underlying problem:

The working-age population has already begun to contract in several large developed countries, including Germany and Japan. By 2030, it will be stagnant or contracting in nearly all developed countries, the only major exception being the United States. In a growing number of nations, total population will begin a gathering decline as well. Unless immigration or birthrates surge, Japan and some European nations are on track to lose nearly one-half of their total current populations by the end of the century. (Howe and Jackson 2011)

That article differs from mine in its implied advocacy of immigration as a solution. To be sure, it does mention "the lawlessness of immigrant youths in large cities [of Western Europe]," but it remains upbeat about the United States "because of its higher fertility rate and because of substantial net immigration, which America assimilates better than most other developed countries" (Howe and Jackson 2011). That optimism was already exaggerated in 2011. Today, mass immigration is just as much a process of cultural and demographic replacement in the U.S. as it is in Western Europe.

Let's be frank. The high productivity of North America, Western Europe, and East Asia has profound behavioral and psychological causes. It is not due to political ideals, universal education, or a particular legal system. It is due to a higher level of social trust, as well as a higher level of cognitive ability and a lower level of personal violence. When immigrants enter that kind of environment, their productivity dramatically rises. They are now working in a society where laws are observed, where information is reliable, and where disputes are not normally settled through violence. We all benefit from that kind of society—simply by virtue of living in it.

That’s the "unearned privilege" that antiracists and right-wing economists love to denounce. Their argument is deceptively simple: “By what right do we deny this privilege to others?  It’s a mere accident of birth! Just think, they’re less productive because we’re keeping them out. So let them in! We’ll all be better off!”

Well, no. Do I have to explain why? 


References

Frost, P. (2015). Two Paths. The Unz Review, January 24
https://www.unz.com/pfrost/two-paths/

Frost, P. (2017a). The Crisis of the 2020s. Evo and Proud, December 19.
http://evoandproud.blogspot.com/2017/12/the-crisis-of-2020s.html

Frost, P. (2017b). The Hajnal line and gene-culture coevolution in northwest Europe. Advances in Anthropology 7: 154-174.
https://file.scirp.org/pdf/AA_2017082915090955.pdf 

Frost, P. (2019a). Autumn in China. Evo and Proud, March 26
http://evoandproud.blogspot.com/2019/03/autumn-in-china.html 

Frost, P. (2019b). Was Western Christianity a cause or an effect? Comment on: J.F. Schulz, D. Bahrami-Rad, J.P. Beauchamp, and J. Henrich. The Church, intensive kinship, and global psychological variation. Science 366 (6466)
https://science.sciencemag.org/content/366/6466/eaau5141/tab-e-letters  

Howe, N., and R. Jackson. (2011). Global aging and the Crisis of the 2020s. Current History, January, pp. 20-25
https://pdfs.semanticscholar.org/9879/fe3ea41e85f5fdfb6bc1ffcc2ae5c44a1a2a.pdf 

Schulz, J.F., D. Bahrami-Rad, J.P. Beauchamp, and J. Henrich. (2019). The Church, intensive kinship, and global psychological variation. Science 366(707): 1-12. 
https://web.ics.purdue.edu/~drkelly/SchulzHenrichetalTheChurchIntensiveKinshipGlobaPsychologicalVariation2019.pdf

Wang, M. (2018). For Whom the Bell Tolls: A Retrospective and Predictive Study of Fertility Rates in China (November 8, 2018). Available at SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3234861  

Stumbling into the future

China's TFR before and after introduction of the one-child policy (Chaparro and Kulkarni 2015). Did that policy really change anything?



The European world has entered "demographic autumn"—on the one hand, fertility rates have fallen below replacement level; on the other, non-European immigration has risen progressively. These two trends can have only one outcome.

A similar demographic autumn is developing in East Asia. In some ways the situation is worse—fertility rates are at their lowest here. The record is held by the provinces of northeastern China, which have a total fertility rate of only 0.75 children per woman (Wang 2018). South Korea has an estimated TFR of 0.96, and a significant number of those births are to immigrant mothers from Southeast Asia (Haas 2018). Japan is doing better only by comparison, with a TFR of 1.4.

As for China as a whole, the rate is officially 1.6 and unofficially 1.05; the authorities revise this statistic upward to include second children who go unreported because they are illegal under the one-child policy (Wang 2018). That policy was scrapped in 2016, yet those second children still seem to be in hiding. Do they really exist? Did they ever? The Chinese government is stuck in a classic quandary: what do you do when you realize you've not been telling the truth?

The truth is that China’s TFR is half of what it needs to maintain its current population. This should be no surprise. In fact, it’s in line with what we see in Taiwan (1.1), in Singapore's Chinese community (1.1), and in Malaysia's Chinese community (1.3). Looking back, one can wonder whether the one-child policy ever had much impact on the TFR (Chaparro and Kulkarni 2015). The decline seems to have deep roots in modern Chinese society:

China faces an intractable and protracted demographic crisis driven by millions of individual family planning choices made by its increasingly wealthy and urbanized population. Policies restricting births imposed by the authorities have played only a contributing role in the drama. Similar aging trends can be seen throughout East Asia, especially in Japan, Taiwan and Hong Kong — territories that never had the types of legal restrictions imposed upon mainland Chinese couples.

[...] The current relaxation of family size restrictions is simply too little, too late. Before the policy was completely abolished in 2013, the Chinese government relaxed the one-child policy by allowing 11 million couples in which both spouses had no siblings to have two children. However, by May 2015, only 18 percent of eligible couples had taken advantage of the opportunity. This shows to what extent China's declining fertility is driven by personal considerations, as opposed to public policies.

In October 2015, the country's National Health and Family Planning Commission estimated that some 90 million families would qualify for the new, two-child policy. By the end of the year, however, only two million families had applied for permission to have a second child. China Daily conducted a survey in 2016 which showed that nearly 60 percent of working mothers do not want a second child, citing time and energy needed to raise it. Other concerns of the women included career risks, the pain of childbirth and little faith in their marriages. (O'Reilly 2019)

This problem is made worse by the gender imbalance: fewer girls than boys are being born. China now has 33 million more males than females. Finally, there is no reason to believe that the decline will stop at one child per woman.


Stumbling into the future

China's workforce is already shrinking, and the total population will begin to shrink before the mid-2020s.  The decline could be offset by pro-natalist measures. For instance, men and women could be encouraged to remain in rural areas and small towns, where conditions are better for family formation. To deal with the shrinking workforce, there could be measures to phase out low-paying jobs through automation and robotization. Of course, there must first be a willingness to act. Unfortunately, such willingness is far from evident, to judge by the current denial and inaction.

China will stumble into its demographic future, with one ad hoc solution after another. One of them may be immigration: "[China] currently hosts some 900,000 legal migrants and untold numbers of illegals, most of them factory workers from Vietnam. Also, desperate Chinese bachelors, unable to find Chinese mates because of the gender imbalance, are increasingly marrying Cambodian or Vietnamese women" (O'Reilly 2019). This is not to say that immigrants will be actively recruited. As is already the case, most will come illegally, being lured by jobs and empty housing. The onus will then be on the authorities to act—in the face of opposition not only from the business community but also from the migrants' home countries, many of which provide Chinese industry with valuable raw materials.

The solutions will ultimately depend on the ideological environment. Westerners often believe that the Chinese are intensely nationalist. In reality, there is a range of views within China, with the majority supporting civic nationalism. This is not coincidentally the view that the government promotes, partly out of conviction and partly to co-opt Tibetans, Muslims, and other minorities. Meanwhile, younger, university-educated people are moving toward the globalist consensus that reigns in the West.

One such person is Yinghong Cheng, who went abroad to study and is now a professor at Delaware State University. His latest book has a chapter titled "Racism and Its Agents in China" (Cheng 2019). In it he argues:

As an ideology, racism or racial discourses do not exist for their own sake or by themselves but always reflect power relations that may be addressed in other social hierarchy-based or identity-related discourses. In China today, racial thinking can appear in various discourses addressed to the political and ideological needs of the party-state, cultural and intellectual elites, and ordinary citizens: nationalism, patriotism, statism, social Darwinism, Han Chauvinism (or Hanism), non-Han ethno-nationalism, populism, and the Chinese civilizational supremacism in general (associated with the traditional ethnocentrism of China). (Cheng 2019, p. 241)

Elsewhere, he describes Hanism as “an ultra-ethnic supremacism” that “comes close to racism in its way of essentializing differences in a condescending manner” (Cheng 2019, p. 264). “The anti-Qing Hanist racism and a racial hierarchy of the world are the twin of the discourse of race in modern Chinese history. Like any other racial discourse in the world, they reflect power relations in reality but construct imaginary orders for a racially ideal—or “natural”—world” (Cheng 2019, p. 16). “… the Han political and intellectual elite exploited the social science disciplines of history, archaeology, and ethnology to establish the centrality of the Han blood and ancestors …” (Cheng 2019, p. 7).

Cheng overstates his case when he describes racism as an ideology that always reflects power relations. This is untrue if we examine its core value: preference for one’s kind. Throughout history and prehistory, humans have cared a lot about their kith and kin, even to the point of sacrificing their lives—and this has been no less true in simple societies with no elite or ruling class. Indeed, the oldest societies were essentially clans of related individuals. Furthermore, kinship is key not only to human life but also to the lives of organisms incapable of having ideas, let alone an ideology. 

Please note: I'm not arguing that kin preference is innate (although that argument can be made). I'm simply saying that it predates ideology and has long been the main organizing principle of society. Perhaps it's now obsolete. Perhaps it’s time for us to become self-defining individuals in a global marketplace. That’s the mainstream liberal argument. But that’s not Cheng's argument. He is arguing that kin preference always was wrong, and now we finally have a chance to get rid of it for good—by eliminating the "agents of racism." How this elimination is supposed to happen is not discussed. Indeed, he never applies to himself the sort of painstaking analysis he applies to others.

In all this, Cheng’s thinking is strangely ahistorical. If kinship has always been the basis for human society, perhaps there is a reason. Perhaps it has been the best way to organize social relations. Or perhaps not. Could we at least have a debate without being accused of base motives? Or being eliminated?

A big problem here is cargo-cult reverence for the West, and this reverence extends to the individualism and globalism that has become so dominant in North America and Western Europe, particularly in elite circles. Cheng denounces China for not doing enough to follow their example, while quoting Chinese writers who point to the resulting problems. If that model of society is already problematic in the West, where it has existed for a longer time, has deeper roots in the culture, and has greater chances for success, why should it do better in a country like China?

Cheng further reveals his ahistoricism when he argues that racism suits elite interests. Yes, it did back in the nineteenth and early twentieth centuries, when elites were nation-based. But they haven’t been that way for some time. Elites no longer have a national conscience, particularly in the West. Their self-interest now pushes them to liquidate the nation-state, notably by outsourcing jobs to low-wage countries and by insourcing low-wage labor for jobs that cannot be outsourced in construction, agriculture, and services. It is this two-way movement—and not "racism"—that is steadily increasing the Gini index, the most common measure of the gap between the rich and the poor.

Do China’s elites still have a national conscience? One can wonder. Unfortunately, this question goes unanswered in Cheng's book. Only nationalism is seen as problematic in the new China, and only nationalism is viewed as serving elite interests. Yet globalism, too, exists within a context of power relations. It, too, serves certain interests. 

As China's working population continues to shrink, will the elites push for higher wages so that labor may be used more sparingly? Or will they keep wages down by bringing in migrant labor? Which scenario is more likely if policymaking is in their hands? And which scenario will get better coverage in the Chinese media?


References

Chaparro, R. and K. Kulkarni. (2015). Does high population growth help or hurt economic development? Cases of China and Pakistan. International Journal of Education Economics and Development 6. 162. 10.1504/IJEED.2015.070629.
https://www.inderscienceonline.com/doi/abs/10.1504/IJEED.2015.070629

Cheng, Y. (2019). Discourses of Race and Rising China. Palgrave Macmillan
https://books.google.ca/books?id=ht-GDwAAQBAJ&printsec=frontcover&hl=fr&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

Haas, B. (2018). South Korea's fertility rate set to hit record low of 0.96. The Guardian, September 3
https://www.theguardian.com/world/2018/sep/03/south-koreas-fertility-rate-set-to-hit-record-low

O'Reilly, B. (2019). China lacks the wherewithal to adjust to demographic decline. Austrian Economics Center
https://www.austriancenter.com/china-lacks-the-wherewithal-to-adjust-to-demographic-decline/

Wang, M. (2018). For Whom the Bell Tolls: A Retrospective and Predictive Study of Fertility Rates in China (November 8, 2018). Available at SSRN: 
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3234861