The idea is simple. Growing rice tends to foster cultures that are more cooperative and interconnected, Talhelm and his colleagues Thursday in the journal Science. Why? Because farming rice paddies requires collaboration with your neighbors, Talhelm tells The Salt. Self-reliance is dangerous. "Families have to flood and drain their field at the same time," he says. " So there are punishments for being too individualistic. If you flood too early, you would really piss off your neighbors." Rice paddies also require irrigation systems. "That cost falls on the village, not just one family," he says. "So villages have to figure out a way to coordinate and pay for and maintain this system. It makes people cooperate."Rice Theory: Why Eastern Cultures Are More Cooperative (NPR)
Wheat, on the other hand, as well as barley and corn, doesn't generally require irrigation — or much collaboration. One family alone can plant, grow and harvest a field of wheat, without the help of others. So wheat farming fosters cultures with more individualism, independence and innovation, Talhelm and his colleagues say. Self-reliance and innovation are rewarded.
How your ancestors' farms shaped your thinking (New Scientist)
Writing in the journal Science, a team led by University of Virginia psychologist Thomas Talhelm provides evidence that China can be divided into two regions with distinct mindsets: the area south of the Yangtze River, which conforms to the aforementioned stereotypes, and the area north of the river, where residents’ attitudes are much closer to those of Westerners.The 2 Cultures of China (Pacific Standard)
The researchers refer to these as the “rice provinces” (those in the south) and the “wheat provinces” (the north). And they provide evidence their different agricultural traditions are the keys to these divergent cultural traditions.
Not mentioned in these articles for some reason is slavery. Wheat wasn't farmed by "individualistic" farmers, it was usually farmed by armies of slaves who where owned by a single person. And debt was usually used to consolidate land holdings. Thus, greedy, selfish assholes could prosper much better than they could in rice cultures, where it is much harder to farm vast plantations with slavery. Also, before wheat agriculture, I would imagine humans were much more like rice farmers, where cooperation and teamwork were important for successful big game hunting.
It also reminds me of the theory that the reason that the Middle Ages were cooperative was because villages could only afford one team of oxen to plow the fields, and thus they had to be shared out among the various farm families and farmed cooperatively. Then came the horse collar (a Chinese invention) and much larger fields could be farmed.