My wife and I decided to take advantage of the spring-like weather and head for the beach.

We were not surprised to find that others had the same idea.

Foot traffic was so thick on the boardwalk that we could move only at a sluggish pace. We didn't care. We were there to look at the dark, beautiful winter water, gently lapping up close, frothy further out. Visually, we drank our fill.

But what struck us as remarkable was how many of our fellow promenaders had no interest in the view. These were the cellphone zombies. There they were, on a crowded beach on the warmest day of the year, faces buried in their phones.

Had the Long Island Sound vanished in a silent puff of mystical energy, I doubt that they would have noticed. How the cellphone zombies avoided colliding with one another is a question best left to Stephen King.

Whatever works on the boardwalk, it fails on the roads. Lately, we read that drivers using their phones are causing so many collisions that insurance premiums can't keep up. Half of teenage drivers surveyed admit to texting while behind the wheel and a two-second glance at the screen exponentially increases the likelihood of an accident. Holding a phone in the hand makes things worse, but, as Tom Vanderbilt notes in his 2009 book Traffic, statistics for hands-free phones are not much better.

Okay, all of this is reasonably well known. (Maybe not the hands-free phone bit, which was news to me, but the rest.)

Cellphones can be dangerous, but the zombies at the beach weren't behind the wheel. Yet, even distracted pedestrians seem to be having more accidents. And there is growing evidence that young smartphone users exhibit the same behaviour as addicts.

But my libertarian conscience does not want to tell anybody else how to live. If people want to come to the beach on a warm winter day and ignore the view, they should have the same freedom as anybody else to enjoy themselves in their own way. True, the zombies turned out to be the ones slowing foot traffic and, in that sense, were uncivil. Given, however, that the zombies constituted a large majority of those strolling along the boardwalk, perhaps our norms of civility need rewriting.

Colour me old: I can remember when strangers greeted each other on the street. There is a warmth in such behaviour, a welcoming, a mutual assurance that each of us belongs. In the days of Jim Crow, many of the norms that supported the segregationist state were informal. Among them was the notion that white men would greet other white men whom they happened to encounter on the sidewalk, but would ignore black men, who would be expected to stand aside. The norms for women were more complex.

Nowadays on campus, students literally bump into their professors and, noses buried in their cellphones, bounce off and keep moving without a word.

Of course, nobody has an obligation to greet anyone else on the street. But social psychologists who study the effects of technology warn us that the lack of acknowledgement creates an "absent presence".

When we are ignored by those around us, stress levels rise. The fight-or-flight reflex might even kick in. Presumably, these effects are minimal or absent in the zombies themselves: They do not notice those around them and, therefore, could hardly respond to being ignored.

But for those whose faces happen not to be buried in their phones, the stress effects of being surrounded by zombies are, in the long run, probably deleterious to health.

The obvious response is that we no longer live in a civil era.

Almost two decades ago, I published a book called Civility: Manners, Morals, And The Etiquette Of Democracy. There I defined civility not principally as good manners (although I do believe that manners matter), but as the sum of the sacrifices we make for the sake of living together.

Fans of the volume have been asking lately whether I might perhaps bring out a revised edition, to take account of our depressing national politics.

Perhaps at some point, I will. But I do not see our politics as the cause of our growing incivility. Our politics is the fruit of our growing incivility.

If we expect better from officeholders and candidates and activists, we have to demand better from ourselves. A good place to start might be saying hello on the street. If that's too big a change, how about if we all look up from our screens a bit more often and enjoy the view.

BLOOMBERG

• Stephen L. Carter is a Bloomberg View columnist.