Your behavior in Starbucks may reveal more about you than you think

How you behave in Starbucks may reveal something about whether your ancestors grew wheat or rice. That’s the conclusion of a new study in China, which finds that people descended from wheat farmers—who largely rely on themselves—typically drink coffee alone, whereas descendants of rice growers—who must work with their community to build complex irrigation fields—tend to sip in groups. These differences persist, even if a person has moved to a city and their family hasn’t farmed or grown rice for generations.

"I find the study very persuasive," says Richard Nisbett, a sociologist at the University of Michigan in Ann Arbor who was not involved in the work. "It certainly is plausible that the differences between cultures are carried across generations even though the practices that gave rise to the culture are now rare.”

Psychologists generally agree that—by very rough measure—Western cultures allow individuality to thrive, whereas most Asian cultures emphasize group responsibility. One line of thinking traces these traits back to early farming practices. Wheat farmers—such as those living in China’s north—can grow their crop pretty much on their own. But it takes a village to build the irrigation systems that flood China’s southern rice paddies. And because rice farming takes about twice as much work per hectare as wheat, early rice farming communities gave rise to cooperative systems of labor. The argument goes on to say that millennia later, these differences in behavior persist.

Thomas Talhelm, a sociologist at the University of Chicago in Illinois, decided to test those theories in an unlikely place: Starbucks. The team observed nearly 9000 people in 256 coffee shops, including local operations and international chains such as Starbucks. They ran their experiment in six cities: Beijing and Shenyang, in China's northern wheat belt; and the southern cities of Shanghai, Nanjing, Guangzhou, and Hong Kong, all in the traditional rice-growing region. Sure enough, on weekdays, roughly 10% more people were drinking their lattes alone in the wheat region than in the rice region. On weekends, that difference dropped to about 5%. (The researchers don’t have an explanation, this is their observation.)

In a second experiment, Talhelm and his team got creative. Psychological studies have also found that when individualists run into a problem they are likely to try to change the situation, he says, whereas collectivists are more likely to adapt themselves to the circumstances. So in selected Starbucks shops, the team set up a chair trap. They would position two chairs so that their backs were separated by the width of the researcher's hips. Patrons walking through the store would have to either move the chairs or turn sideways to squeeze through them. Most of the 678 Starbucks patrons just squeezed on through. But whereas only 6% of the southerners moved the chairs, 16% of the northerners did. (Follow-up questions by the researchers found that about 90% of the people in the Starbucks shops were from the respective local rice or wheat cultural region.)

The fact that these differences appeared among mostly middle-class city people suggests that rice-wheat differences are still alive and well in modern China, the authors conclude today in Science Advances .

Nisbett thinks the study did its job. "The chair technique is clever," he says, adding that it’s far superior to observational research, survey-based research, and studies in the lab.

Zhou Xiaoyu, an economist at Friedrich-Alexander University in Erlangen, Germany, who is originally from Beijing, agrees. "I believe they have done a good job at demonstrating that rice versus wheat farming has profound effects on cultural norms."

Talhelm says his team is considering trying a similar study in India, where there is also a split between rice- and wheat-growing areas. Unlike the different regions in China, where there are north-south climatic differences, the differing regions in India are all in similar climatic zones. Climate is a variable that could influence culture, so taking that issue out of the equation could answer the question of whether colder climes induce individualism.

Talhelm notes that the results also raise questions about expectations that Chinese would become more individualistic as they modernized, grew wealthy, and congregated in cities. He notes the cities in the southern rice areas are wealthier, more crowded, and more developed than the northern cities of Beijing and Shenyang. Yet the northerners still appear to be more individualistic. "People’s farming legacies seem to be more important than [gross domestic product] in explaining their everyday behavior," he says.