The young can get away with IM-ing while playing a computer game or the like, but there’s a risk: if you grow up assuming that you can pay attention to several things at once, you may not realize that the way in which you process such information is superficial at best. When you’re finally forced to confront intellectually demanding situations in high school or college, you may find that you’ve traded depth of knowledge for breadth and stunted your capacity for serious thought.
Along with the costs to strong learning and deep thinking, hours spent in the thrall of alluring machines exact a toll from your attention to human beings. At the very least, time online is subtracted from real-world interactions, such as conversation, sharing a meal, or even having sex.
Rapt, Attention and the Focused Life – Winifred Gallagher