Study: No. of social-media users over 50 doubles

? This is not your father’s social network — oh, wait a minute; maybe it is.

The phenomenal growth of Facebook, Twitter and other social sites in the past year has come in part because of a surge in adoption by older members, with a new national poll released Friday saying that the share of Americans over 50 using social networks doubled in the past year.

In April 2009, just 22 percent of Americans aged 50 and over were using social networking tools such as Facebook, according to the Pew Research Center’s Internet & American Life Project. But by May of this year, 42 percent of Americans 50 and older were posting status updates or sending tweets. A near-majority — 47 percent — of people between the ages of 50 and 64 are now using social networks.

“Young adults continue to be the heaviest users of social media, but their growth pales in comparison with recent gains made by older users,” Mary Madden, author of the Pew report, said in a prepared statement.

While Facebook may have started as a way for college undergraduates to flirt, it may end up being the thing that closes the gap between generations, as the thorny question of whether to “friend” Mom and Dad becomes an increasingly universal dilemma, even for middle-aged people. The Pew report found that 13 percent of Americans aged 65 and older now log into a social network on a typical day, compared to 4 percent in 2009.