I'll just check my phone for a sec

You sit down for a chat with a new acquaintance but before you're even started they've placed their phone carefully on the table in front of them. Why? Are they waiting for a call? Do they just enjoy marvelling at its chic plastic beauty? Either way, a new study suggests this familiar habit could be interfering with our attempts to socialise.

Przybylski and Weinstein asked 34 pairs of strangers to spend 10 minutes chatting to each other about "an interesting event that occurred to you over the past month". The participants sat on chairs in a private booth and for half of them, close by but out of their direct line of view, a mobile phone was placed on a table-top. For the other pairs, there was a note-book in place of the phone.

After they'd finished chatting, the participants answered questions about the partner they'd met. The ones who'd chatted with a phone visible nearby, as opposed to a notebook, were less positive. For example, they were less likely to agree with the statement "It is likely that my partner and I could become friends if we interacted a lot". They also reported feeling less closely related to their conversational partner.

A second study with a fresh set of participants was similar, but this time some of the 34 pairs of strangers chatted about a mundane topic, whilst others chatted about "the most meaningful events of the past year." Again, some of them did this with a phone placed nearby, others with a notebook in the same position.

For participants with the notebook visible nearby, having a more meaningful conversation (as opposed to a casual one) boosted their feelings of closeness and their trust in their conversational partner. But this extra intimacy was missing for the participants for whom a mobile phone was visible. When the researchers debriefed the participants afterwards they seemed to be unaware of the effects of the mobile phone, suggesting its adverse effects were at a non-conscious level.

Why should the mere presence of a mobile phone interfere with feelings of social intimacy in this way? Przybylski and Weinstein can't be sure, but they think that modern mobile phones might trigger in the mind automatic thoughts about wider social networks, which has the effect of crowding out face-to-face conversations. Considered in this way, the present findings are an extension of the wider literature on what's known as non-conscious priming (for example, the presence of a brief-case makes people more competitive).

A weakness of the study is that the researchers didn't compare the effects of the presence of a mobile phone against an old-fashioned land-line phone, or other forms of technology. So it's not clear how specific the effect is to mobile phones.

Also, as the authors acknowledge, this is just a preliminary observation that poses all sorts of future questions requiring further research. For example, did the presence of a mobile phone alter the behaviour and conversational style of the participants, or did it merely change their perceptions of the social experience? Would the effects be the same for people who are already in a close relationship?

But for now, Przybylski and Weinstein concluded: "These results indicate that mobile communication devices may, by their mere presence, paradoxically hold the potential to facilitate as well as to disrupt human bonding and intimacy."