You don't have to use your phone to be distracted. The presence of your phone is enough to lose your focus.
Experiment
Researchers discovered this by having two groups of students do difficult and easy assignments. One group had a telephone on the table, while the other group had telephones hidden out of sight.
The second group scored better
The students who did not have a telephone on the table did better on average on all assignments. The difference was large, especially with the difficult assignments.
Concentration decreases
It was also recently discovered that we don't communicate as well with others when there is a telephone nearby. Are you working on a difficult task or are you having a personal conversation? Then it is best to store your phone.
