One of the strong points of Siva’s perspective is his modulated portrayal of tech-savvy and tech-unsavvy kids. In his essay, he writes, “Every class has a handful of people with amazing skills and a large number who can’t deal with computers at all.” And in his first post, he observed, “Just because they can text and use Facebook does not mean they know or understand anything about digital media,” while also citing “some rather profound uses of digital technology in the university classroom.”

His range offers a measured alternative to the extremists—both the enthusiasts who laud techno-youths as an evolutionary advance over elders who stumble with e-mail and the bilious curmudgeons who title their anti-youth-tech sallies with flat invective. We have teens and young adults whose techno-habits pull away from books, ideas, history, knowledge, and eloquence, and we have teens and young adults whose techno-habits lead them to the current campaign, serious trends in music and the arts, and reading groups.

The question is: On each side, how many?

I would point the arrow well on the frivolity side, and here are a few reasons why.

—Social networking is the primary activity for teens online, as you can see here.

—When Esther Hargittai, whom Siva mentions, polled college students on their online destinations, Facebook and MySpace ranked #1 and 2, but what really surprised her was the low interest in politics, law, economics, or policy.

—Siva says that “the claim that kids won’t read books are just not true,” but the number of them who want to read books certainly has declined. The National Endowment for the Arts “Reading at Risk” study found that the percentage of 18-to-24-year-olds who read a book on their own went from around 59 percent in 1992 to 50 percent in 2002. At the same time, of course, digital tools and diverse screens began to fill their bedrooms.

—Siva also notes that library visits went up significantly from 1994 to 2004. But while visits are up, circulation of books has fallen. The rising volume is due to the spreading media offerings in the library, and I’m not confident that they use them more studiously in the library than they do at home.

Some people claim that students use technology for homework, and productively so. But look at homework numbers in the High School Survey of Student Engagement and the National Survey of Student Engagement. On the 2006 High School Survey, only 10 percent of students logged more than five hours per week “Reading/studying for class.” On the 2006 National Survey, only 11 percent spent at least 25 hours per week “preparing for class” (professors estimate 25 hours as necessary to success). Fully 44 percent of them spent less than 10 hours per week doing so.

Are the top performers acquiring knowledge and refining taste with digital tools? A few of them, no doubt. But that group is dwarfed by the group piling up heavy opportunity costs watching SportsCenter, texting buddies, posting on the day’s happenings, surfing personal profiles, talking on the cell to boy- or girlfriend . . .

Think of how our nation would advance if the rising generation took but one hour per week away from digital playtime and devoted it to studying, say, the history and cultures of the Middle East.