Using your cell phone at the table is like burping: pure rudeness.

Among the most common rude gestures, with their attendant consequences, placing your cell phone at the table as soon as you sit down to eat with friends has become one of the most common. Putting your cell phone at the table like a napkin, especially at dinner, is equivalent to a burp. A harmless gesture, but one that is seriously rude, to our detriment and that of those around us during the pleasure of being together while eating. No one would dream of placing other personal items on the table—think of a set of keys that, incidentally, clutter up your pants or jacket pockets—but with a smartphone, we feel entitled to do anything. Even to cultivate a contagious bad manners that shatters the fundamental rules of table etiquette.

At this point, you might as well not care about style, and that would still be a mistake, so let's try to convince ourselves to turn off our phones at dinner with other reasons. The first is scientifically documented: you're wasting pleasure. A double pleasure, that of food and that of conviviality.

The Journal of Experimental Social Psychology published research demonstrating how much pleasure diminishes if your dinner is accompanied by a cell phone. And its possible trilling. On a scale of 1 to 7, the wasted pleasure caused by a misplaced smartphone is between half a point and one point. Not a small amount. And be careful: the wasted pleasure affects both the appreciation of the food and the enjoyment of the conversation . Over 11 percent of people who eat with a cell phone in hand don't appreciate the quality of the food on their plate. It's as if they don't enjoy it.

According to statistics, 94 percent of people get annoyed when they see the other person distracted by their smartphone screen while they're talking. And 92 percent feel the need to make eye contact when speaking to someone. So why put this gun on the table while we're eating, ready to fire—that is, to distract us? Is it really that complicated to take a break from cell phone conversations by setting up an automatic reply? People say: I have to reply for work. This is more false than true, because there are no answers that must always be given in real time. And if someone asks for one, they need to be explained that a few minutes' internet connection break, like the right to a lunch break, doesn't change anyone's work life. If anything, it improves it.

There are other side effects of this bad habit. It increases anxiety . A smartphone turned on and placed on the table always announces something. It's not detached. There could be a text message, a phone call (even an unwanted one), the relaying of a piece of news. All things that have the same effect: increasing the stress we've accumulated throughout the day. And yet, dinner should produce the opposite result: freeing us from these anxieties, thanks to good food and good company.

Smartphones at the table isolate people, creating a wall of separation between them . Even if they don't realize it. Look—and this is unfortunately a common sight—at a couple sitting at a restaurant table, having dinner, both with their smartphones turned on and on. Their heads are buried in their respective devices, they smile and tap away as if no one were there, and their partner for the evening becomes a stranger. It's a dinner party of ghosts.

Using your cell phone while dining requires small but significant etiquette tips updated with the latest technology. One thing to keep in mind is to leave it in your pocket or purse, with the silent mode on. If you're expecting an urgent call, you can get up once (not every ten minutes, and not at the start of lunch or dinner) with the excuse of going to the bathroom and checking for incoming calls. Once you've finished eating and the conversation continues elsewhere, perhaps in the living room, don't immediately pick up the phone, and don't break the spell of good company. Finally, unless absolutely necessary, avoid taking photos of the dishes.