One of the more striking findings in the study of adults' social networking site use is the growth among older Internet users in recent years, a Pew release reported Monday.
Internet users age 65 and older have roughly tripled their presence on social networking sites in the last four years, from 13 percent in the spring of 2009 to 43 percent currently.
Online adults' use of Twitter has also grown, the survey found, more than doubling since November 2010 to 18 percent.
The age group mostly likely to use Twitter are those age 18 to 29, the survey found; 30 percent of that group are tweeting regularly.
The survey was conducted by telephone from April 17 to May 19 among a sample of 2,252 adults age 18 and older, with a margin of error of plus or minus 2.3 percentage points.