What explains China's cultural heterogeneity?

“You must come to Chengdu!”, urged my new Chinese friend. “It’s very tolerant and liberal. Men can be openly gay. Women in my family are assertive - that’s the local culture. Beijing - where I went to university - is very different. Chinese people joke that Chengdu husbands are ‘henpecked’, controlled by their wives”.

My eyes lit up, with great excitement!

East Asia scores as culturally tight; norm deviation is strictly punished. Yasheng Huang blames China’s imperial examinations, instilling rote-learning. Southern (versus Northern) Chinese score higher for collectivism; Thomas Talhelm suggests this is because they grew rice, which requires far greater cooperation and interdependence.

But Chengdu was a major imperial city, heavily reliant on rice! How then did Chengdu become so queer-friendly - hosting China’s first gay wedding?

Obviously, I eagerly arranged to visit, then nose-dived into the empirical literature. This post harness insights from big data to understand China’s subnational heterogeneity, then uses qualitative history to trace cultural evolution and possible causes.