Washington, DC (Scicasts) – A new study from conducted by the Pew Research Center’s Internet and American Life Project found that 19% of U.S. Internet users now say they use Twitter or another service to share updates about themselves, or to see updates about others. The company says these figures represent a significant increase over previous surveys in December 2008 and April 2009, when 11% of Internet users said they use a status-update service.

The study shows that three groups of Internet users are mainly responsible for driving the growth of such activity: social network website users, those who connect to the Internet via mobile devices, and younger Internet users, under the age of 44.

In addition, the study suggests that mobile devices play a key part in this growth of Twitter users, as figures highlighted that the more devices someone owns, the more likely they are to use Twitter or another service to update their status. Fully 39% of Internet users with four or more Internet-connected devices (such as a laptop, cell phone, game console, or Kindle) use Twitter, compared to 28% of Internet users with three devices, 19% of Internet users with two devices, and 10% of Internet users with one device.

However, Pew Research said that it will probably become more difficult to track status updating as an independent activity, since social network updates feed into Twitter and vice versa. Though, the company affirmed that a “social segment” of Internet users is actively flocking to both social network sites and status update services. This segment is likely to grow as ever more Internet users adopt mobile devices as a primary means of going online.

The full report is available here.