NEW YORK (AP) -- More people are embracing social networks like MySpace and Facebook, but use of these friend-gathering sites remains a much bigger phenomenon among the young, according to a report released Wednesday by the Pew Internet & American Life Project.
Of the roughly three-quarters of U.S. adults who go online, 35 percent use social networking sites such as MySpace, Facebook or LinkedIn, Pew found in a survey of 2,250 people late last year. Just 8 percent of adult Web users were on social networking sites four years ago.
Through the most recent survey and other polls last year, Pew determined just how much more likely it was for younger people to be participating in social networks. Some 65 percent of online teenagers 12 to 17 use the sites, and three-quarters of Internet users between 18 and 24 have a profile. In comparison, just 7 percent of Internet users who are 65 and older are on the sites.
Among the more surprising of Pew's findings released Wednesday: Some 17 percent of adults have multiple profiles on one site and 4 percent have profiles for "different parts of their personality."
But before you start wondering just how many of your friends have multiple personalities, Pew senior research specialist Amanda Lenhart noted that these accounts often emphasize different parts of someone's life, such as sports or hobbies. Someone might have a hockey-focused profile and a separate one indulging his interest in gardening.
Men and women used the sites in equal proportions, but there were differences when it came to race. About 31 percent of white Web users said they have a profile on at least one social network site, compared with 43 percent of black and 48 percent of Hispanic adults.
Lenhart said the difference can be attributed to the respondents' ages, as "younger segments of the population (are) much more diverse." Similarly, because young people tend to make less money, the survey also found that respondents with lower household incomes were more likely to use social network sites than their richer counterparts.
The median ages of MySpace and Facebook users were 26 and 27 years old, respectively. At the career-focused LinkedIn, it was 40.
Though a growing number of companies have a presence on social networking sites, friendship is people's main reason for logging on. The bulk of adults, 89 percent, said they use their online profiles to stay in touch with friends. Only 28 percent said they use it to make business or professional contacts and promote themselves at work.
To flirt was the least popular reason: Only 20 percent of grown-ups said this is a reason they log on.
Facebook has about 150 million active users, mostly outside the U.S., with people over 30 the fastest-growing demographic. MySpace boasts 125 million active users, with 76 million of them in the U.S. and the grown-up demographic its biggest growth area in December.
Pew's surveys had margins of error ranging from 2.4 to 6 percentage points.