Don’t harass them about how much they play video games. The digital native boosters are right that this is the social and emotional world in which young people live. Just make sure when they’re doing schoolwork, the cellphones are silent, the video screens are dark, and that every last window is closed but one.

“The good thing about this phenomenon is that it’s a relatively discrete behavior that parents actually can do something about,” she says. “It would be hard to enforce a total ban on media multitasking, but parents can draw a line when it comes to homework and studying—telling their kids, ‘This is a time when you will concentrate on just one thing.’ ”

He advises students to take “tech breaks” to satisfy their cravings for electronic communication:

Those who were interrupted more often scored worse on a test of the lecture’s content; more interestingly, those who responded to the experimenters’ texts right away scored significantly worse than those participants who waited to reply until the lecture was over.

Follow-up studies performed years later found that the kids who were better able to delay gratification not only achieved higher grades and test scores but were also more likely to succeed in school and their careers.

“The depth of their processing of information is considerably less, because of all the distractions available to them as they learn.”

“Engaging in Facebook use or texting while trying to complete schoolwork may tax students’ capacity for cognitive processing and preclude deeper learning,”

memory of what they’re working on will be impaired if their attention is divided.

First, the assignment takes longer to complete, because of the time spent on distracting activities and because, upon returning to the assignment, the student has to refamiliarize himself with the material. Second, the mental fatigue caused by repeatedly dropping and picking up a mental thread leads to more mistakes.

It can happen only when the two tasks are both very simple and when they don’t compete with each other for the same mental resources.

That’s a problem, because these operations are actually quite mentally complex, and they draw on the same mental resources—using language, parsing meaning—demanded by schoolwork.

“students engage in substantial multitasking behavior with their laptops and have non-course-related software applications open and active about 42 percent of the time.

Now that these devices have been admitted into classrooms and study spaces, it has proven difficult to police the line between their approved and illicit uses by students.

“Young people have a wildly inflated idea of how many things they can attend to at once, and this demonstration helps drive the point home: If you’re paying attention to your phone, you’re not paying attention to what’s going on in class.

One large survey found that 80 percent of college students admit to texting during class; 15 percent say they send 11 or more texts in a single class period.

It’s multitasking while learning that has the biggest potential downside,” she says. “I don’t care if a kid wants to tweet while she’s watching American Idol, or have music on while he plays a video game. But when students are doing serious work with their minds, they have to have focus.”

their learning is far spottier and shallower than if the work had their full attention.

so common that many of them rarely write a paper or complete a problem set any other way.

“It really seems that they could not go for 15 minutes without engaging their devices,

“study something important, including homework, an upcoming examination or project, or reading a book for a course,” it wasn’t long before their attention drifted: Students’ “on-task behavior” started declining around the two-minute mark as they began responding to arriving texts or checking their Facebook feeds. By the time the 15 minutes were up, they had spent only about 65 percent of the observation period actually doing their schoolwork.