Who is using Tweeter?

Thirteen percent of online Americans use Twitter, up a full 5% from November 2010, according to a Pew Research Center study released Wednesday.

Much of that growth came from younger adults, Pew found. Nearly one in five U.S. Internet users ages 25 to 34 use Twitter, up from 9% in November. Fourteen percent of users between 35 and 44 also now use the service, up from 8% a half-year previous.

But Twitter isn’t exclusively the domain of young adults; 8% of participants between 50 to 64 and 6% over the age of 65 consider themselves Twitter users, respectively.

In addition, the study found that men are slightly more likely to use the service than women. Fourteen percent of online men in the U.S. use Twitter, compared to 11% of women.