This species is racially diverse (within limits) and eager to assimilate the fun-seeming bits of foreign cultures — food, a touch of exotic spirituality. But no less than Brexit-voting Cornish villagers, our global citizens think and act as members of a tribe.

They have their own distinctive worldview (basically liberal Christianity without Christ), their own common educational experience, their own shared values and assumptions (social psychologists call these WEIRD — for Western, Educated, Industrialized, Rich and Democratic), and of course their own outgroups (evangelicals, Little Englanders) to fear, pity and despise. And like any tribal cohort they seek comfort and familiarity: From London to Paris to New York, each Western “global city” (like each “global university”) is increasingly interchangeable, so that wherever the citizen of the world travels he already feels at home.

Indeed elite tribalism is actively encouraged by the technologies of globalization, the ease of travel and communication. Distance and separation force encounter and immersion, which is why the age of empire made cosmopolitans as well as chauvinists — sometimes out of the same people. (There is more genuine cosmopolitanism in Rudyard Kipling and T. E. Lawrence and Richard Francis Burton than in a hundred Davos sessions.)

It is still possible to disappear into someone else’s culture, to leave the global-citizen bubble behind. But in my experience the people who do are exceptional or eccentric or natural outsiders to begin with — like a young writer I knew who had traveled Africa and Asia more or less on foot for years, not for a book but just because, or the daughter of evangelical missionaries who grew up in South Asia and lived in Washington, D.C., as a way station before moving her own family to the Middle East. They are not the people who ascend to power, who become the insiders against whom populists revolt.

In my own case — to speak as an insider for a moment — my cosmopolitanism probably peaked when I was about 11 years old, when I was simultaneously attending tongues-speaking Pentecostalist worship services, playing Little League in a working-class neighborhood, eating alongside aging hippies in macrobiotic restaurants on weekends, all the while attending a liberal Episcopalian parochial school. (It’s a long story.)