Move over, kiddos. Social networking is attracting new — and older — devotees, according to a Pew Research Center analysis released last week. It finds that 35 percent of adult Internet users now have a profile on at least one social networking site. And among online adults ages 35-44, 30 percent have a profile.

Although the share of online adults with a profile quadrupled from 8 percent in 2005, Pew found that the young are still more likely to use the sites. Among 18- to 24-year-olds, 75 percent of those who go online have a profile.

The value of these sites grows with the numbers, suggests social psychologist Robert Kraut of Carnegie Mellon University in Pittsburgh.

He says his son and daughter-in-law now post pictures and videos of his new grandchild on Facebook. "So my wife and I are looking at Facebook much more because there's actual value."

Pew found that most adults use social networking for personal rather than professional reasons. About half of adult users are on MySpace, and just under a fourth use Facebook. Just 6 percent use Linked In, which is geared toward business networking.

"If you choose one site over another, you go to a site where there's already more people," Kraut says.

Adults say they use social networking for various reasons:

• 89 percent to keep up with friends;

• 57 percent to make plans with friends;

• 49 percent to make new friends.

Some use the sites to organize with others for an event, issue or cause; to flirt; to promote themselves or their work; or to make business contacts.

Of social networking site users, 51 percent have two or more online profiles; 43 percent have only one. About 60 percent let only friends view their profiles.

Cate Riegner, vice president of Netpop Research, a San Francisco firm that studies online behavior, says social networking grew 93 percent from 2006 to 2008.

During that time, Facebook grew 500 percent. That site began for college students and opened to the public in 2006.

The Pew report is based on two telephone surveys — one completed in December of 1,650 Web users ages 18 and over, and a survey completed in May of 328 adults who use social networks.