How rice farming remade East Asians

Rice farming, Ming dynasty (Wikicommons)

Why are East Asians more collectivistic? Why is their approach to thinking more relational and less abstract? They may have been pushed in that direction by the requirements of rice farming.

We humans have adapted not only to nature but also to culture—in short, to ourselves and our creations. This is seen in our genetic evolution, which accelerated more than a hundred-fold when hunting and gathering gave way to farming, which led to further changes in our cultural environment:

• population growth

• rise of villages, towns, and cities

• formation of the state and its monopoly on violence

• resolution of disputes through codified law and state-imposed justice

• development of written language to store information for future use and to reach a wider audience across time and space

• increase in peaceful interaction with non-kin, and a corresponding decrease in the role of kinship as the organizing principle of society

• and so on.

Humans have adapted to an ever-widening range of cultural environments, and not just to a limited range of natural environments. Genetic evolution has speeded up accordingly (Cochran and Harpending, 2009; Hawks et al., 2007; Rinaldi, 2017).

Yes, culture can decide who will get to pass on their genes. Like climate or disease, it can remake us through natural selection, just as we can remake it through our own choices. Human bodies and human culture have thus been remaking each other along trajectories that differ from one population to another.

Rice farming vs. wheat farming: differences in mindset

That reciprocal remaking is called “gene-culture coevolution.” It caught the interest of behavioral scientist Thomas Talhelm, who wished to examine how the Chinese coevolved with different types of farming. To that end, his research team administered three psychological tests to 1,162 Han Chinese from rice-growing or wheat-growing regions. The results point to differences in mindset between the two groups (Talhelm et al., 2014).

Abstract versus relational thinking

In the first test, the participants were shown sets of three words and asked: “Choose the two that go together the best.” For example, if the words were “train,” “bus,” and “tracks,” the two words could belong to either the same abstract category (“train” and “bus” are vehicles) or the same relational category (“train” runs on “tracks”).

Participants more often chose the abstract category if they came from a wheat-growing region and the relational category if they came from a rice-growing region. Admittedly, the difference might simply be geographic: wheat farming tends to be in northern China and rice farming in southern China. The type of farming might therefore be incidental because northern and southern China differ in other ways.

To control for north-south differences, the research team restricted their study to adjacent counties in the five central provinces along the rice-wheat border. Again, the participants from the rice side of the border thought more relationally than those from the wheat side.

Individualism versus collectivism

In the second test, the participants were asked: “Draw a picture of yourself in relation to your friends.” A previous study found that Americans drew themselves about 6 mm bigger, Europeans 3.5 mm bigger, and Japanese a bit smaller.

On average, the participants from wheat-growing regions drew themselves 1.5 mm bigger than their friends, whereas the participants from rice-growing regions drew themselves 0.03 mm smaller.

Universalism versus particularism (i.e., loyalty to friends, nepotism, cronyism)

In the third test, the participants were asked: “Imagine yourself going into a business deal with 1) an honest friend, 2) a dishonest friend, 3) an honest stranger, and 4) a dishonest stranger.” In this imaginary story, a dishonest businessman causes the participant to lose money, and an honest one causes the participant to make money. In each case, money can be used to reward or punish the business partner.

In an earlier version of the test, Singaporeans were more likely than Americans to reward a friend than to punish a friend. In Talhelm’s study, the participants from rice-growing regions were more likely than those from wheat-growing regions to reward a friend than to punish a friend. The two groups did not differ in their treatment of strangers.

In summary:

• Chinese from rice-growing regions seem to be more collectivistic, more relational in their way of thinking, and more likely to make a big distinction between friends and strangers.

• Chinese from wheat-growing regions seem to be more individualistic, more abstract in their way of thinking, and less likely to make a big distinction between friends and strangers.

• The above differences were just as true for participants who had only an ancestral connection to farming of either sort.

For Thomas Talhelm, the cause lies in the different requirements of 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, pp. 603-604)

Rice farming has been much more widespread in East Asia than in the West. That difference may have pushed the two regions in different directions, not only in their means of subsistence but also in their ways of being and thinking:

Western culture is more individualistic and analytic-thinking, whereas East Asian culture is more interdependent and holistic-thinking. Analytic thought uses abstract categories and formal reasoning, such as logical laws of noncontradiction—if A is true, then "not A" is false. Holistic thought is more intuitive and sometimes even embraces contradiction—both A and "not A" can be true. (Talhelm et al., 2014, p. 603)

Rice farming vs. wheat farming: differences in age at first birth and in alcohol tolerance

The above findings have been expanded upon by agricultural economist Chen Zhu and her research team. Using genetic data from 4,101 individuals across China, they calculated the polygenic score of each participant for various physical and behavioral traits (Zhu et al., 2021).

What’s a polygenic score? It’s a sum based on all the genetic variants that are known to influence a particular trait. If your score for stature is high, you have a genetic propensity for being tall. And you probably are.

For each participant and for each trait, Zhu’s research team compared the polygenic score with the county of birth, specifically the proportion of farmland used to grow rice. The trait/county correlations were then investigated for possible confounds. Because rice farming is more common in southern China, there could be confounds with latitude, temperature, certain minority groups, and so on.

After controlling for those confounds, the researchers were left with two significant findings. In rice-growing regions, the participants had:

• A younger age at first birth - The reproductive schedule was shifted toward younger ages, perhaps because of shorter life expectancy.

• A lower tolerance for alcohol – There was a higher frequency of defects for alcohol-metabolizing enzymes, more so for aldehyde dehydrogenase than for alcohol dehydrogenase.

A defect in either enzyme makes it harder for the liver to break down alcohol, but the first defect is more serious. In about 36% of East Asians, it causes facial flushing, nausea, and tachycardia after alcohol consumption. Not surprisingly, carriers suffer less from alcoholism and alcohol-related liver disease (Brooks et al., 2009; SNPedia, 2020).

Why did rice farming select for alcohol intolerance?

Chen Zhu argues that natural selection had more time to favor alcohol intolerance in rice-growing regions than in wheat-growing ones. This was because rice farmers were the first to produce a grain surplus that could be used to make fermented beverages.

Zhu seems to be assuming that alcohol consumption has always been maladaptive; therefore, once people began to consume alcohol, natural selection favored those who were less alcohol-tolerant. Yet fermented beverages have long been enjoyed, and physically tolerated, in much of the world—at least for eight thousand years in the Mediterranean region (McGovern, 2003).

So why are fermented beverages still consumed in much of the world? They are safer to drink than untreated water, and such water was usually the only kind available until recent times. Wine in particular kills bacteria through the combined effect of its organic acids, ethanol, and low pH (Carneiro et al., 2008; Cueva et al., 2012; Møretrø and Daeschel, 2004; Waite and Daeschel, 2007).

Alcohol was thus adaptive as long as people had no safe alternative. Then, during the Tang dynasty, the Chinese discovered a safe alternative in the form of boiled water, particularly tea:

A tea revolution marked the Tang dynasty (618-906), permanently relegating alcohol to a lesser position among the culturally privileged intoxicants. … [It] was a significant shift away from heavier patterns of intoxication, all the more so since the previous period had been a ‘golden age’ for alcohol. (Dikötter, 2004, p. 29)

As tea culture spread throughout East Asia, it was accompanied by a decline in alcohol consumption. Among East Asians, that decline coincided with a sharp increase during the last 100 generations in the frequency of the defective variant of aldehyde dehydrogenase (Chen et al., 2022; Okada et al., 2018).

Relative abstinence continued until the nineteenth century:

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, 2023)

But why did alcohol intolerance become more frequent where rice was grown than where wheat was grown? One reason may be the more collectivistic mindset. Once tea drinking took hold, rice farmers may have been more willing to jump on the bandwagon.

Another reason may be the difference in alcohol content between rice wine (18-25%) and wheat/millet beverages, notably Huangjiu (8-20%). Once a safe alternative to alcohol became available, with none of the latter’s drawbacks (i.e., drunkenness, alcoholism, loss of cognitive and motor function), fermented beverages may have encountered more opposition where rice was grown because of their higher alcohol content.

Thus began the East Asian tradition of drinking beverages made from boiled water (Ye, 2017). Elsewhere, fermented beverages remained the preferred drink.

Facial flushing, before and after alcohol consumption (Wikicommons, Brooks et al., 2009)

What about alcohol intolerance in Amerindians?

There is still no consensus on alcohol intolerance among Amerindians, partly because the topic is largely taboo, partly because certain studies were poorly done, and partly because the degree of alcohol intolerance seems to vary among different Amerindian groups (Bennion and Li, 1976; Goedde et al., 1992; Zeiner, 1983).

Perhaps all humans were alcohol-intolerant when they were hunter-gatherers. When some of them adopted farming, they now had a grain surplus and could make fermented beverages. Natural selection then began to favor the ability to break down alcohol in the liver. The physiological difference may therefore exist between those Amerindians who adopted farming and those who did not.

That scenario is the reverse of Chen Zhu’s. In other words, natural selection initially favored alcohol tolerance because fermented beverages were the only safe alternative to water. Later, East Asians discovered a better alternative in the form of boiled water. At that point, natural selection went into reverse and began favoring those East Asian individuals who had less tolerance for alcohol.

East Asians vs. Northwest Europeans: The Large Society Problem

Because of its importance among East Asians, rice farming has shaped their culture and, hence, their mindset and behavior. That basis of their society seems to be key to their trajectory of gene-culture coevolution. 

Nonetheless, the East Asian trajectory is far from unique. Whatever the geographic context, certain adaptive problems inevitably arise as a society becomes larger and more complex, and those problems cannot be solved in an infinite number of ways. This is true for things like how to trade, how to read and write, how to resolve disputes peacefully, how to abide by codified rules and, above all, how to live together in a large society where most non-family interactions are no longer between close relatives.

That is the "large society problem" (Frost, 2020). It has not been fully solved anywhere, but East Asians and Northwest Europeans have gone the farthest toward a solution. In general, the solution has been to weaken the relative importance of kinship and to strengthen forms of sociality that can include everyone, and not just close kin.

To that end, a special mindset is needed. You must be susceptible to social norms that are absolute, universal, and independent of kinship. You must feel guilt or shame if you break those norms, and you must feel empathy not only for family but also for non-kin. Above all, you must be socially oriented, and not just self-oriented.

Despite the above constraints on solutions to the large society problem, the workable solutions do differ significantly, particularly between East Asians and Northwest Europeans. Because East Asians are more collectivistic, due to the influence of rice farming, their behavioral controls tend to be more external to the individual. Northwest Europeans, because of their greater individualism, tend to be more susceptible to internal controls. 

The similarities and differences can be summarized as follows: 

Similarities:

• East Asians and Northwest Europeans have both adapted to a larger social environment by becoming more empathetic toward non-kin and more susceptible to universal social norms.

Differences:

• East Asians are more collectivistic. Their internal controls over behavior have been strengthened by an increase in cognitive empathy. Their external controls over behavior have been strengthened by an increase in shaming, family-community surveillance, and inculcation of correct behavior by parents and community.

• Northwest Europeans are more individualistic. Their internal controls over behavior have been strengthened by an increase in affective empathy and guilt proneness. Their external controls have been strengthened but not to the same extent. Western societies are primarily “guilt cultures” and not “shame cultures” (Bedford and Hwang, 2003; Benedict, 1946; Frost, 2020; Lebra, 1971).

As with evolution in general, neither trajectory has been teleological. East Asians did not adopt rice farming in order to solve the large society problem. Through rice farming, they became “pre-adapted” to the future: they unintentionally created a cultural model that would become more useful as their societies grew larger. Other societies were not so lucky.

Remember, we see the past from a biased point of view. The present is composed of societies that have survived, whereas the past is composed largely of those that have not. We easily forget the latter and wrongly assume that our ancestors took one of the few paths possible for humans. In reality, there were many paths. But most led to dead ends.  

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