Keeping a smartphone around isn’t smart.

Simply being near your phone can tax your ability to think, according to a recent study released by the University of Texas, Austin. That’s true whether it’s on the table during lunch, face down on your desk at work, or charging by your bed. It’s even true when the phone is switched off.

The researchers had 800 participants take a series of tests like remembering a phone number and logical reasoning questions like “which of the following things does not belong with the rest” — both with a smartphone near them and with the smartphone in a different room. The result: People who’d been instructed to leave their phones in another room performed better than those participants who had their phones either face down on a desk, in a purse, or in a pocket.

 

This simple iPhone hack can help boost your brainpower and increase cognitive performance at work.(Jay Zehngebot/illustration)

 

The reason? Simply ignoring your phone takes a toll on your brain. Even If the participants told the researchers that they hadn’t been thinking about their devices, the researchers believe their brains were spending energy in the background, resisting the temptation to check email or instagram.

Smartphones, of course, have plenty of pros to them that even include things like educational apps that can teach us everything from a foreign language to cooking. But this is far from the first study to show that smartphones have a serious downside. Indeed, they can do everything from ruin your dinner date to lower your ability to empathize and prevent you from connecting deeply with the people around you.

The lesson: Leave the phone at home — or at least in another room. It may make you smarter, more engaged, and frankly, less annoying to be around.