The carbs that divide the north and south in China

I'm a bit skeptical but apparently people in the north and south of China have different personality traits driven by the staple carbs they have historically cultivated (WSJ):

A study published Friday by a group of psychologists in the journal Science finds that China’s noodle-slurping northerners are more individualistic, show more “analytic thought” and divorce more frequently. By contrast, the authors write, rice-eating southerners show more hallmarks traditionally associated with East Asian culture, including more “holistic thought” and lower divorce rates.

The reason? Cultivating rice, the authors say, is a lot harder. Picture a rice paddy, its delicate seedlings tucked in a bed of water. They require careful tending and many hours of labor—by some estimates, twice as much as wheat—as well as reliance on irrigation systems that require neighborly cooperation. As the authors write, for southerners growing rice, “strict self-reliance might have meant starvation.”

A bit of warranted skepticism from Sarah Hoyt guest blogging at Instapundit: "’d need to see a lot more studies done before I thought it was even a major influence. Also, culture is not genetic. Yes, certain propensities might be genetic, but the human individual can still shape himself to a great degree."