I don’t own a smartphone. I’m guessing that there are only about ten other people in the world who don’t have one. (They probably live in super-remote areas or they’re too young to push the buttons.) I’ll probably have to cave in and get one eventually. But if I do, it looks like I’ll need to be cautious about where I store it.

Most of my friends and coworkers love their smartphones. So they keep them close by – often right next to them on their desks. But according to a recent research study, this may not be a good idea. It seems that keeping your phone close by could actually cause cognitive impairment.

In the study, 520 subjects were asked to silence their phones, so the phones wouldn’t ring or vibrate. Then the researchers divided the subjects into three groups:

  • The first group were told to leave their phones in the lobby, outside of the laboratory.
  • The second group kept their phones in their pockets or bags (wherever they would normally store them).
  • And the third group were told to place their phones next to them, face-down on their desks.

Then the subjects were asked to perform a series of cognitive tasks. For instance, they had to solve math problems, complete complex patterns, and recall lists of randomly-generated letters.

Investigators found that the people who left their phones in the lobby were the most successful. They did slightly better on the cognitive tasks than the people who had their phones in their pockets or bags. And they did much better than the people who had their phones sitting next to them.

The researchers concluded that when people have their smartphones nearby, it’s more difficult for them to think clearly. They don’t even have to be looking at their phones. Just being in close proximity with their phones causes what the investigators called “brain drain.”

When people have their phones nearby, they have to work to ignore them – and this requires some cognitive effort. Thus, their ability to focus on other things, solve problems, and complete tasks is reduced.

So what should you do to prevent this from happening? Get rid of your smartphone!  (Ha! No, just kidding. I know you don’t want to do that.) But here’s a pretty simple solution – researchers suggest that you store your phone in your bag or a closed desk drawer. If it’s out of sight, it will help to keep it out of mind.


Ward, A. F., Duke, K., Gneezy, A., & Bos, M. W. (2017). Brain drain: The mere presence of one’s own smartphone reduces available cognitive capacity. Journal of the Association for Consumer Research. 2(2), 140 – 154.