Texting is the main reason.

Phys reports.

Some college kids spend a fifth of class time on digital devices

(HealthDay)—College students spend one-fifth of their time in class using digital devices—such as smartphones—for non-educational purposes, new research reveals.

The main culprit is texting. Almost nine out of 10 reported that texting was their main digital diversion while in class. About three-quarters said they emailed or checked the time on their devices. Seventy percent reported checking in on social media (for example, Facebook), while 40 percent surfed the web. One in 10 spent time in class playing games on their devices.

“Most of us love technology,” said study author Barney McCoy, an associate professor in the College of Journalism and Mass Communications at the University of Nebraska-Lincoln. “And we want it to benefit us. But technology also affords a view that can be distracting.