It's understandably tempting to play with your shiny new iPhone when you're out for dinner. But new research suggests that you don't even have to shower attention on your smartphone to sour your relationship with your dinner mate; in fact, just leaving your phone on the table — untouched — can do interpersonal damage. Here, a brief guide to the research, and why, for the umpteenth time, you should really consider keeping your phone in your pocket:

What happened in these studies?
Researchers Andrew K. Przybylski and Netta Weinstein of the University of Essex in Britain wanted to see if the mere presence of a phone could affect interpersonal connections. In one experiment, they placed two strangers together in a private booth and asked them to discuss a "moderately intimate topic" (something that had happened to them in the last month, for example) for 10 minutes. The pair sat in two chairs facing each other. Off to the side, not directly in their line of vision, was a desk. Sometimes the desk had a notebook on it. Other times it had a cell phone. After the chat, participants were asked to complete questionnaires about the closeness they experienced with their new pal.

What did they find?
On average, people who didn't have a cell phone lurking nearby experienced feeling closer and more connected to the stranger they just chatted with. Their curiosity piqued, Przybylski and Weinstein decided to set up a slightly different experiment.

What did the researchers do next?
They employed the same setting, but this time, they asked strangers to discuss either a "casual topic" (their thoughts and feelings about something like plastic trees) or a "meaningful topic" (their most important life events of the past year). Again, participants were given 10 minutes to chat, with either a cell phone or notebook on a nearby desk. At the end, they filled out questionnaires about "relationship quality, their feelings of trust, and the empathy they had felt from their discussion partners," says Helen Lee Lin at Scientific American

And the results?
A cell phone's presence had no adverse effect on strangers discussing a casual, meaningless topic. But when a cell phone was near a pair discussing something meaningful, they reported feeling less trust in their their partners, and felt the person who sat across from them was less empathetic overall. "Thus, interacting in a neutral environment, without a cell phone nearby, seems to help foster closeness, connectedness, interpersonal trust, and perceptions of empathy," says Lin — "the building-blocks of relationships."

Why are phones such a distraction?
The research team has a few ideas. Among them: While the increasing sophistication of phones certainly make the gadgets more diverting — with games, apps, and social media all just a few taps away — the gadgets also subconsciously signal a person's wider network of connections. The mere presence of a wired-up smartphone is a reminder that its owner knows lots of people, and chats, texts, and Facebooks with them on that phone — even if it's not happening right at that moment. That inhibits feelings of intimacy you'd otherwise get when you're sitting face-to-face with someone. The lesson? "Put your cell away when you're chatting with your partner or friend," says Diana Villbert at Care 2, "before your only companionship is Angry Birds."

Sources: Care 2, New York Daily NewsScientific American