Last week, my wife and I went out to dinner in a crowded restaurant that, lucky for us, had one open booth in a faraway corner.

In the booth next to us sat a family – Mom, Dad, Teenage Son, Teenage Daughter and Grandpa.

At first glance, this multigenerational slice of American life had good times written all over it. As the late Barbara Bush once observed, “At the end of your life, you will never regret not having passed one more test, not winning one more verdict, or not closing one more deal. You will regret time not spent with a husband, a friend, a child, a parent.”

To which, alas, we now must add one more family member – and I’m not talking about Grandpa.

Enter the smartphone.

While Mom and Dad chatted quietly, both kids stared hypnotically at their phones, scrolling and occasionally tapping their screens between bites of burger and fries. And there in the middle sat Grandpa – no phone, no one to talk to and, saddest of all, no chance to revel in what life is supposed to be all about.

I thought about this family on Wednesday when I read that come September, a new law will greet kids age 15 and under returning to school in France: No smartphone or tablet use allowed. Period.

The goal is twofold – keep kids focused on the classroom and, in the process, combat their ever-growing addiction to the small screens that now virtually rule their young lives.

As Jean-Michel Blanquer, the country’s education minister, told French media this week, “We know today that there is a phenomenon of screen addiction, the phenomenon of bad mobile phone use. Our main role is to protect children and adolescents. It is a fundamental role of education, and this law allows it.”

Vive la France!

And at the same time, heaven help the United States.

According to a recent report by the National Center for Education Statistics, the percentage of American public schools that prohibit cellphones and other devices capable of sending text messages fell from almost 91 percent in 2009-2010 to just under 66 percent in 2015-2016.

Why the rapid decline?

Some researchers point to pressure from parents, particularly in this age of school shootings, who want to be able to reach their children at any instant during the school day. According to Nielsen’s “Fourth Quarter 2016 Mobile Kids Report,” 90 percent of parents surveyed cited easy access to their kids as their primary reason for providing them with a cellphone in the first place.

But at what cost?

Check the average adolescent’s phone usage and I guarantee that contact with Mom or Dad pales by comparison to the endless messaging with friends, the self-obsessed selfies, the mind-numbing parade of video games and the constant social media check-ins to see who’s saying what about whom.

It’s what the social psychologists call “behavioral addiction.” One of them, New York University associate professor Adam Alter, told the New York Times last year of a private school in the San Francisco Bay Area that prohibits any and all tech devices.

“The really interesting thing about this school is that 75 percent of the parents are tech executives,” said Alter, author of “Irresistible: The Rise of Addictive Technology and the Business of Keeping Us Hooked.”

He added, “What was it about these products that made them, in the eyes of experts, so potentially dangerous?”

Or, in the case of our dinner neighbors the other night, so anti-social.

Not long after we sat down, a man approached the booth next to us, hand outstretched, and greeted the father of the family with a rousing, “Great to see you!”

Dad rose from his seat, stepped a foot or two away from the booth, and the two proceeded to chat one-on-one for at least the next 15 minutes.

Then the guy’s wife arrived with her two teens in tow, greeted Mom the same way, and off they went on their own extended tete-a-tete.

But here’s the truly lamentable part.

Teenage Daughter never, not once, even looked up from her phone. Nor did Teenage Son.

And the two kids who dutifully followed their mother over to the booth? Both retreated to a nearby wall, where they too stared unblinking at their cellphones for the entire “visit.”

“Maybe they’re all texting each other,” I whispered to my wife.

Or maybe they were in another world, far from the chatter and clatter of the restaurant, oblivious to anything and everything going on around them.

And Grandpa? He just sat there, staring around the restaurant with a pleasant-but-vacant look on his face. So much for bonding with the grandkids.

Don’t get me wrong. On balance, smartphones are an amazing technological development. For a journalist like me, they represent a radical shift from how I used to do my job to how I do it now.

And while we might debate the age at which most kids should get their first cellphone – according to Nielsen, more than half have one by the time they’re 10 – there’s no question that kids are safer (and more trackable) with an iPhone or whatever in their backpack or pocket.

But the next time you walk down Main Street or visit the mall, spend a few minutes counting the number of adolescents (or grownups, for that matter) riveted to their phones.

Then, picture them doing the same thing while in school.

Some Maine school systems, at least, recognize the problem. The Maine Principals Association website now lists 17 cellphone policies imposed by schools and/or districts around the state – my favorite is Morse High School in Bath, where students deposit their phones in a hanging shoe organizer as they enter class, then pick them up on their way out.

So, here’s to the French and all those other educators who recognize the slippery slope from smartphones to stupidity.

And here’s to Grandpa, who undoubtedly could have taught his two grandchildren a thing or two about what real memories are made of.

If only they’d looked up long enough to ask.

Bill Nemitz can be contacted at:

bnemitz@pressherald.com