The ubiquitousness of smartphones and digital devices is certainly making people ruder and more selfish to be around, but now new research from the University of Texas at Austin has found that the mere presence of your phone significantly reduces your cognitive capabilities.

Investigators did two studies on almost 800 subjects, with the first one testing cognitive abilities on a computer while either having their phone on the desk next to them face down, in their pocket or bag, or in a separate room, with all set to silent mode. That experiment showed that those with the phone in the other room scored much higher on the brain game.

"We see a linear trend that suggests that as the smartphone becomes more noticeable, participants' available cognitive capacity decreases," said co-author Adrian Ward, Ph.D., an assistant professor at the McCombs School of Business. "Your conscious mind isn't thinking about your smartphone, but that process—the process of requiring yourself to not think about something—uses up some of your limited cognitive resources. It's a brain drain."

The other test used the same computer cognitive test and the same phone protocol, but some participants were asked to turn their phone completely off. Researchers discovered that those who were most dependent on their phones did worse on the tests, but only if their phone was on the desk or close to them in a bag or pocket. "It's not that participants were distracted because they were getting notifications on their phones," said Ward. "The mere presence of their smartphone was enough to reduce their cognitive capacity."