There's one other question which is raised by the Pinker quote just below. He says the more cosmopolitan, mobile, open regions are more inclined to impersonal exchange, and have shifted away from communitarian sharing or authority norms.
It gets me thinking about the great cosmopolitan cities - like New York. Why are they so attractive? And what has that to do with impersonal ties or liberal values that Pinker says they exemplify?
Are they more fluid and impersonal and transactional and atomistic? Yes, at least here in New York, or London or Toronto or LA. Of course, there may be vicious social hierarchies, from Ms Astor's Four Hundred through to the nightclub pecking order or the competitiveness of Wall St. But it is a plural hierarchy, with gaping holes. You pick your own greasy pole.
Is it the anonymous impersonal aspects we specifically seek when we move here? To be sure, many people hit the road to the big city because they want to leave behind the restrictions of small town life or community disapproval.
But I think it is mostly aspiration which makes people move. It is the attractive force, not the repellent force that makes people pack their bags and come. In some ways, it is like the old answer Mallory gave when he was asked why he wanted to climb Everest: "Because it's there."
Here in New York, G and I don't know our neighbors at all, apart from the people next door who we know by sight and say hello to the elevator. We don't particularly want to invest in knowing them or more extensive local ties.
We don't want a lot of social obligation or community involvement. We get home from work and we mostly just want to spend time together, after being around all sorts of others in a transaction-like way all day. We can spend our time mostly as we want after work.
But it isn't really anonymity which makes us want to live here. It's the energy and stimulation.
The city has few roots itself. There's little left of old New York, gone through fires and redevelopment and real estate speculation. It is a seething mobile mass of transition, full of every extreme - achievement, beauty, loneliness, love, greed.
New York is the cinematic dreamworld of childhood picture books and romance at the top of the Empire State and police chases under subway tracks and intrigue in skyscrapers. It is larger than life. It is a daily miracle of eight million people grinding together.
Yet it is also unequal and ruthless and cramped and noisy.
So let's step back and think about this trend from community to impersonal values. To what extent will the evolution of the economy mean the world ends up looking more (or at least feeling more) like New York? Do you get the radiant energy or just the split atoms?
Historically, after all, cities had to replenish their population from the countryside because they were so unhealthy. Ur and Nineveh and Tyre and Alexandria and Rome all fell.
Cities are fragile in long-term perspective. They go through periods of remarkable growth and creativity, and then they stagnate. Florence is beautiful in part because it has hardly grown since the quattrocento. It illuminated the world for fifty years, and then the light faded. The same could be said of turn of the 19th century Vienna.
There are different kinds of great city. The commercial city (Hellenistic Alexandria, Venice, Amsterdam, London, New York) is different from the imperial city or religious capital (Rome, Vienna, Moscow, Xi'an, Beijing) or industrial center (Cleveland, Manchester, Dusseldorf).
So it could also be an issue of the evolution of a kind of city, a great commercial capital rather than an aristocratic showpiece. Cities are not necessarily cosmopolitan or mobile at all. They can be closed fortresses or overgrown company towns.
Is it really just impersonal exchange which makes New York so exciting, though? Surely the excitement of the city is the sense that there is experience here which can't simply be bought in Peoria or Kansas City or a village back in Fujian Province. It is ambition, hope, dreams.
Is it freedom from we want here in New York, or freedom to, in Isaisah Berlin's old phrase?
Maybe that's the phase transition. We've had a century where we have - slowly and painfully - evolved institutions which deal with freedom from - want, hunger, violence, scarcity. But we haven't really begin to get our heads around the next stage, freedom to.
The trouble is in the past it has led to utopian disaster or chaos. Or a more militaristic, violent people swept in from the steppes or the hinterland or the empire and strangled the liveliness of the city. Or they just exhausted their vitality and went into decline.