I agree, and I'd say these differences between cities fall under the label of 'culture'. Population density and personal interaction are necessary but insuffici

I agree, and I'd say these differences between cities fall under the label of 'culture'. Population density and personal interaction are necessary but insufficient. I taught SAT prep in China for a couple of months. If population density and personal interaction were all that are required for innovation, my students would have been creative geniuses. Instead, the results of cultural patterns such as fear/obedience/submission to authority dominated my impressions of all but a few.