The Annenberg Center for the Digital Future at the University of Southern California is reporting this week that 28% of Americans it interviewed last year said they have been spending less time with members of their households. That’s nearly triple the 11% who said that in 2006.

These people did not report spending less time with their friends, however.

Michael Gilbert, a senior fellow at the center, said people report spending less time with family members just as social networks like Facebook, Twitter and MySpace are booming, along with the importance people place on them…

But Gilbert said the Internet is so engrossing, and demands so much more attention than other technologies, that it can disrupt personal boundaries in ways other technologies wouldn’t have.

“It’s not like television, where you can sit around with your family and watch,” he said. The Internet, he noted, is mostly one-on-one.