Researchers at the University of Southern Maine studying distraction and cellphones have discovered something interesting: not only does your ability to handle complicated cognitive tasks diminish when you try to use a cellphone while doing something else, the “mere presence of a cell phone may be distracting.”

As the article’s abstract [pdf] explains,

Research consistently demonstrates the active use of cell phones, whether talking or texting, to be distracting and contributes to diminished performance when multitasking (e.g., distracted driving or walking). Recent research also has indicated that simply the presence of a cell phone and what it might represent (i.e., social connections, broader social network, etc.) can be similarly distracting and have negative consequences in a social interaction. Results of two studies reported here provide further evidence that the ‘‘mere presence’’ of a cell phone may be sufficiently distracting to produce diminished attention and deficits in task-performance, especially for tasks with greater attentional and cognitive demands. The implications for such an unintended negative consequence may be quite wide-ranging (e.g., productivity in school and the work place).

This isn’t the first study to measure the impact of the presence of phones on people: one recent study found that during a 10-minute conversation, participants reported lower “relationship quality” when a cell phone was present than when it was not.

In this experiment, undergraduates in a psychology course took surveys to report their level of attentional difficulty, and their level of attachment to their cellphones. They were randomly paired, set at a long table, and told they’d be working on “a set of timed tasks that required attention and concentration for quick and accurate completion.”

There were two tests. In the digit cancellation test, students had to cross out either a target number in a long string of numbers, or (in the harder version) two adjacent numbers that added up to the target. In the trail making test, they had to draw lines between numbered circles (think of those connect-the-dots pictures you drew when you were a child) without picking up the pencil, or (in the harder version) alternate between consecutive numbers and letters.

After explaining the test, the researchers would then leave the room, but “accidentally” leave behind either a small notebook, or a cellphone.

So what did they find?

For the simple digit cancellation task, there were no differences as to the number of lines completed or the number of correct cancellations due to presence of a cell phone or notebook (Fs < 1). Neither was there a difference with regard to the number of lines completed with the additive cancellation task (F < 2). However, the correct additive cancellations achieved did differ significantly as a function of the cell phone presence versus notebook…. On this more demanding task, those with the cell phone had poorer performance than those with the notebook (Ms = 19.81 and 23.25, respectively).

Considering the performance on Part A of the TMT, the number of sequential circles successfully realized did not differ between the cell phone and notebook presence (F < 1). On the more difficult Part B task, however, those with the cell phone present achieved fewer circles (M = 12.42) than their counterparts with the notebook (M = 15.46), F(1, 48) = 6.79.

A second experiment run with student’s own phones yielded similar results:

Results of this study provide support for a ‘‘mere presence’’ effect of the cell phone in reducing attentional capacity and performance, but only when the task was more attentionally and cognitively demanding. Interestingly, based on the number of lines completed, the quantity ofwork was comparable for cell phone and notebook groups; it was the quality of the work (i.e., accuracy) that suffered.

So what’s going on? As first author Bill Thornton told Time,

The sight of a cell phone reminds people of the “broader social community” they can access via texting and the internet…. “With the presence of the phone, you’re wondering what those people are doing…. Even if it’s just mental, your focus is not on the task at hand, whether it be trying to write an article, get this spreadsheet set up, or just socializing; your mind is elsewhere.”

Obviously this has implications for phone policies at school, but also for policies regarding laptop and tablet use as well: if such effects are present with iPads, for example, that needs to be factored into use policies. It would also be interesting to know if there are other things you can do to make phones less distracting: for example, having different modes or identities on a device (e.g., switching from a personal user / identity to student user / identity when in class), switching on whitelists during school hours, or wearing a device like the Memi that alerts you only of critical incoming calls.