Years of research (and culture clashes) have shown that East Asians are more collectivistic than their individualistic Western counterparts. Now, new research argues that this cultural gulf may stem from what those peoples' ancestors farmed.

Within China, people from traditional rice-farming areas have a more collectivist mindset than people from traditional wheat-farming areas, the new study finds. Other factors, such as climate or urbanization, fail to explain the cultural differences.

Though the study is limited to China, "I think this can go at least part of the way into explaining the differences between East and West," study leader Thomas Talhelm, a doctoral candidate at the University of Virginia, told Live Science. Europeans historically grew wheat and a similar crop, barley. [10 Things That Make Humans Special]

The cultures of China

Talhelm first got the idea to study the effect of farming on Chinese culture while living in Guangzhou and teaching high school in 2007. Guangzhou is in southern China, and Talhelm noticed that when he later moved to Beijing in northern China, residents were less conflict-averse and more straightforward. It's a difference Chinese natives notice as well, he said.

"They'll call people from the North more direct or more brash," Talhelm said.

Certain changes in dialects also occur as you move from southern China to northern China, Talhelm learned, with the Yangtze River acting as a dividing line. The Yangtze, it turns out, is also the point at which rice farming in the South transitions to wheat farming in the North.

Rice farming is labor-intensive and requires irrigation, which forces a community to work together, Talhelm said. Wheat farming, on the other hand, is a more individualistic pursuit. Thus, he wondered if the cultures that evolved out of these two methods of farming might still persist.

Collectivism vs. individualism

To find out, Talhelm and his colleagues recruited 1,162 students, all from the Han ethnic group, from cities across northern and southern China: Beijing, Fujian, Guangdong, Yunnan, Sichuan and Liaoning. China is an ideal place for this sort of analysis, as the country has had one central government for a long time, and as the Han ethnicity makes up about 92 percent of the population. This uniformity prevents politics or ethnic background from confounding the analysis.

Each participant performed several tasks, meant to measure his or her level of collectivism and individualism. In the first, the person was presented with images of three objects, such as a train, a bus and tracks, and asked to pair two together. Previous research finds that people from individualistic societies tend to pair the train and the bus, lumping them into the abstract category of "modes of transportation." People from collectivistic societies take a more holistic, relational view, typically pairing the train with the tracks. [7 Personality Traits That Are Bad for You]

The researchers also asked participants to diagram their social networks, drawing circles to represent themselves and their friends. Previous studies have shown that people from individualistic cultures draw their own circle larger than those of their friends. People from collectivistic cultures draw their circle the same size, or sometimes smaller, than their friends' circles.

A third task tested how people would choose to punish and reward friends versus strangers; people from Asian countries are more likely to reward their friends than punish them, while Americans are more prone to punish friends who are dishonest than reward those who are helpful, as compared with Singaporeans.

Wheat and rice

In each task, people from northern China scored as more individualistic than people from the South, Talhelm and his colleagues report today (May 8) in the journal Science. The differences were large, noted Joseph Henrich, a University of British Columbia psychologist who was not involved in the study, in an accompanying editorial. For example, people from historical wheat-farming areas in the North matched objects based on analytic categories (putting together the bus and the train, for example) 56 percent more often than people in rice-farming areas in the South.

Likewise, people from wheat-farming areas drew their social network circles about 0.06 inches (1.5 millimeters) larger than those of their friends, while people from rice-farming areas made their circles and their friends' circles the same size. [5 Ways Relationships Are Good for Your Health]

In comparison, Europeans draw their circles 0.14 inches (3.5 mm) larger than their friends', and Americans draw theirs 0.24 inches (6 mm) larger. ("Americans are number one in the world in self-inflation," Talhelm said.)

To make sure the difference wasn't due to other factors, Talhelm and his colleagues analyzed provinces along the wheat-rice border: Sichuan, Chongqing, Hubei, Anhui and Jiangsu. In these provinces, the climate is the same from county to county, but the prevalence of rice versus wheat farming differs. The results revealed the same collectivist-individualistic split among neighbors, with counties with more wheat acting more individualistically than rice-farming counties. The prevalence of pathogens and modernization also failed to explain the schism — because China's government has established Special Economic Zones in the South, these regions tend to be more developed than those in the North.

The researchers also found that while modernization has sent divorce rates up countrywide, wheat provinces had 50 percent more divorces than rice provinces. And patents held on inventions, which are more common in individualistic cultures, are disproportionately held in wheat provinces.

Ancestry's echoes

The participants in the study were all college students, and likely none of them had ever farmed, Talhelm said. But the idea that ancestors' cultures influence people in the modern day is not a new one. Cultures that arise from a herding lifestyle, known as "honor cultures," tend to be more violent and concerned with personal reputation than are farming cultures. In the United States, regions settled by Irish and Scottish honor-culture immigrants more than 200 years ago continue to have higher rates of accidental death and homicide, particularly murders related to defending one's honor.

The rice-wheat split probably doesn't explain all of the difference between East and West, Talhelm said. The magnitude of the difference between North and South China is about 60 percent of the cultural difference seen between East and West. But the finding might explain why modernized, urbanized nations like Singapore, Japan and South Korea remain very collectivist despite GDPs that match those in the West, Talhelm said — all three are historically rice-growing regions. It's not clear how these traits are passed on, Talhelm said, who cautioned that he is not arguing that they are genetic in origin.

The next step, Talhelm said, is to test the idea in other countries, including rice-growing regions in West Africa. He has already done preliminary work on India, he said, where the rice-wheat schism is east-west rather than north-south. There, he said, the cultural differences linked to farming seem even stronger.

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