Northern China has grown wheat and millet for thousands of years, while southern China has grown rice. The time when most of the population was involved in agriculture is long past, but the type of crop grown affects the culture so strongly, researchers have claimed that even urban residents behave differently depending on their home region's crop. Specifically, wheat farming encourages a more individualistic culture than rice, and this manifests in everyday behaviors.
Wheat farming is usually practiced as a relatively solitary activity, with each farm operating independently. Paddy rice requires irrigation systems that encourage farmers to cooperate. Chinese rice farmers are also more inclined to share labor than wheat farmers, working together to plant and harvest each other's crops.
These practices seeped into the culture of the regions, argues Dr Thomas Talhelm of the University of Chicago, and affected even non-farmers. To test this theory, Talhelm, Dr Xuemin Zhang of Beijing Normal University, and the University of Virginia's Professor Shigehiro Oishi watched people in 256 chain stores (chosen for their uniformity) in six Chinese cities (including Hong Kong).

Based on a sample size of almost 9,000 people, Talhelm reports in Science Advances that people in rice-growing regions were less likely to sit alone than those in cities where the local crop is wheat. Likewise, when the researchers moved chairs to block the aisle in the same coffee shops, responses differed by region.
In 2014, Talhelm, Zhang, and Oishi conducted a laboratory study of individualism versus interdependence, testing how people regarded their own importance against the collective good and how much weight they put on the distinction between friends and strangers. Despite 65 years of communist rule, and some migration between regions, northern Chinese were more individualistic in their outlook than collectivist southerners.
Attributing this to crops sounds almost like astrology, but it's part of "subsistence theory", which holds that the behaviors required for survival over generations affect regional cultures and continue to be seen in other activities. By testing within China, the researchers eliminated many of the alternative explanations that interfere with comparisons between nations.
On weekdays, 32 percent of people in wheat cities sat alone in cafes, compared to 22 percent of those surrounded by rice fields, although the gap shrank on weekends. Tourist areas were avoided, but it is likely the gap would have been larger still if out-of-towners could have been excluded. When confronted with inconveniently placed chairs, almost all southerners adapted themselves in the manner typical of collectivist cultures. Northerners, both employees and customers, were more likely to take control and move the furniture. The differences applied independently of age, time of day, or local incomes.
Even after centuries of British rule, and greater modernization, Hong Kong remains true to its rice-growing roots.
