LONDON — In the movie “Closer,” two lives tangle after some chance eye contact on a crowded London street. Never mind that people on city streets do not bounce along in slow motion, never mind that most of them are not as beautiful as Natalie Portman or Jude Law. But do let us remind ourselves that people in cities are not friendly. And let us take a lesson from the troubled souls on the screen, for whatever their faults, they do know how to make friends of strangers.

I am from Los Angeles, where people prefer the comfort of cars and mobile phones to interaction with strangers. Still, as a child I never realized that my mother, who is from Ohio and makes friends in line at the grocery store, was an urban anomaly. But years of observation of gruff behavior have made me wiser. As it turns out, most city people don’t like to be cordial with strangers.

Real cities are not as sexy as the “Closer” London, which was full of kindred spirits looking for love. Real city people go to nightclubs to meet strangers; in public, we avoid each other at any cost. Buses and underground trains are tense and silent, and seasoned riders follow the unwritten code of conduct that forbids smiling and speaking. And God forbid you should accidentally make eye contact with somebody on the street; that gesture is always met with a cold glance to the side or above your head, a lame denial of the existence of other people in the fast and furious street.

London is a great city, but strangers here are more hostile than even in New York, which is infamous. In fact, some Londoners report that strangers in New York are remarkably friendly. Here in London, unlike any other place I’ve ever been, you get shoved. Sidewalks, crowded or not, are shoving free-for-alls where fellow pedestrians push, whack and stomp all over your poor body, leaving it bruised and battered by the time you get home. There are no apologies, not even so much as a nod.

In fairness, the same people who shove and stomp would probably give you directions if you were lost, and a lot of them give money to beggars. It’s not heartlessness that prompts rude street behavior; it’s habit. I’ve become a shover, too. Besides, we can’t all be like Natalie Portman. It’s OK to ignore strangers sometimes, but we can’t ignore the whole world the whole time. Sure, there is something cozy about headphones and cell phones. There is comfort in shutting out the street — but we still have to walk on it. It may be a harsh world, and people in cities may forget to be polite when they have packaged sandwiches to buy, telephone calls to make, and music to listen to. Unfortunately, it’s no excuse.

City life has gotten lonely. We move dazedly from one destination to the next, our social radii limited to insular groups of friends. The really sad thing is that, by ignoring each other, we’re creating problems. Growing numbers of single men and women living in cities have had it with their solitary lives but don’t know how to meet people in the city. According to the lead story in Sunday’s New York Times Magazine, growing numbers of successful people in major cities around America are hiring professional matchmakers to find them spouses.

And love lives aren’t the only things suffering in this world of, to quote the poet Adrienne Rich, “eyes met and unmeeting.” The consequences of stranger-hating reach further and, according to some, can be fatal. Hans Monderman, a Dutch traffic expert and street designer, told Wired Magazine in December that car accidents happen when drivers, overwhelmed with street signs, traffic lanes and traffic signals, don’t pay attention to other cars and people on the road.

Monderman’s observations of fast and inefficient city traffic have prompted him to redesign several major intersections in northern Holland into circular plazas that rely not on complacent rule-following, but on interaction with strangers — specifically, on eye contact. His designs remove most signs and lanes in order to promote interaction among busy city folk. Monderman’s streets — which he sees as models for all cities, even the biggest — are terribly safe. “Everyone looks out for each other,” he tells the reporter for Wired. Indeed, his designs boast a zero accident record.

College life, like country life, is a little like a Monderman intersection. Until we graduate to real cities, we actually do meet friends and strangers as we pass them on our way to class, in the dining hall, by chance. We’re open to meeting new people because our situations change as a matter of course. For us, the lesson is to take to heart the friendliness that comes naturally to campus life and never to lose it. Living in a major city this semester has thrown the pleasantness of college life into relief for me. Let us all be ever aware of the life-changing (and life-saving) potential that friendliness can have for city life.

Helen Vera is a junior in Jonathan Edwards College and an occasional columnist.