A customer from Beijing and one from Hong Kong walk into Starbucks. A chair blocks the path between the counter and their seats. Who of the two moves the chair?
It's not a joke. It's a psychology experiment, designed to test the long-lasting imprints of a culture's agrarian past.
A new study in the journal Science Advances says that over thousands of years, rice farmers in southern China have evolved a culture of interdependence not found in northern, wheat-growing parts of the country.
The authors say those influences persist even in China's modern, relatively wealthy cities, among people who have never farmed. And they show up in how people behave in their daily lives — even as they navigate their local coffee shop.
The study found people were much less likely to move the Starbucks chair in southern China, where rice has been the staple crop for thousands of years, than those in the wheat-farming north.
According to what the researchers call the "rice theory of culture," growing rice demands more cooperation than growing most other crops. Neighbors in rice-farming villages have to coordinate when they will flood and drain their paddies, for example.
And since rice requires about twice as much labor as wheat, rice-growing villagers often share the workload.
Over the centuries, people developed "folkways and habits of thoughts and behavior norms that, once they're established, you're not even thinking, 'I'm doing this because I'm a rice farmer.' If you're thinking about it at all, you're thinking about it as, 'I'm doing this because I'm a good person. Because that's how I was raised. Because that's what they talk about in school,' " said psychologist Andrew Ryder at Concordia University in Montreal, who was not part of the research team.
Moving the chairs
To test their theory, University of Chicago psychologist Thomas Talhelm and colleagues went to Starbucks in five cities: Beijing and Shenyang in the wheat-growing north; and Guangzhou, Shanghai and Hong Kong in the rice-growing south.
They chose the Western coffee chain for its uniformity, introducing fewer variables in the environment that might complicate the results.
Researchers put two chairs a hip's width apart in high-traffic aisles and watched how customers got past them.
In southern China, almost everyone squeezed through them. Just 6 percent moved a chair.
In the north, on the other hand, 16 percent were chair-movers.
"Previous research has found that when people in independent cultures like the United States encounter a problem, they're more likely to want to change the environment to solve that problem," Talhelm said. "But when people in interdependent cultures like Japan encounter problems, they're more likely to try to fit [themselves] into the environment."
Moving the chair rather than squeezing past it suggests a more independent mindset, he said.
The study also found northerners were more likely than southerners to sit alone: There were about 10 percent more singletons in northern Starbucks shops compared with southern ones during the week, and about 5 percent more on weekends.
Talhelm said the findings go against the common theory that "as areas become more wealthy, more modernized [and] more urbanized, people become more individualistic or more Western."
Even in Hong Kong, among the wealthiest, most modern and most urban cities in China, chair-movers were rare and few people sat alone.
"People's farming legacies seem to be more important than GDP in explaining their behavior," he added.
The researchers also checked population density, age, gender, climate and disease presence. Nothing explained the results as well as the rice versus wheat split.
The findings fit with a different type of study Talhelm and colleagues did that tested students on measures of thinking style. They found the same cultural differences between rice-growing regions and wheat-growing regions, even among students from rice-growing or wheat-growing regions of the same county.
The rice theory had been "floating around for quite a long time," Ryder said, but "I think people hadn't even necessarily expected that it would be all that testable."
Now, he noted, several studies from different approaches are converging on the same results.
And, he added, it's an important reminder that China is not a cultural monolith. No country is.
"Get away from 'one country equals one culture,' " he said.
Next, Talhelm is testing the theory in India, another country with a rice/wheat split.