Short interruptions (such as the few seconds it takes to silence that buzzing smart phone) have a surprisingly large effect on one's ability to accurately complete a task. Interruptions of just three seconds can double your chances for making errors.
Journal of Experimental Psychology: General, January 2013
It's no doubt that Cell Phones have made life a lot easier and offer a great deal of conveniences not known to generations past. That being said they also have a downside and that is the constant barage of interuptions that affect productivity and accuracy as shown in the above study.
There is also an Attention Deficit Disorder effect that takes place, which is of great concern as it relates to children and teens who have cell phones.