Blogging by teenagers and young adults has dropped by half over the past three years as they turn instead to texting and social networking sites such as Facebook, a new study shows.

The study released this week by the Pew Internet and American Life project also found that fewer than one in 10 teens were using Twitter, a surprising finding given overall popularity of the micro-blogging site.

According to the report, only 14 percent of teenagers who use the Internet say they kept an online journal or blog, compared with a peak of 28 percent in 2006 -- and only 8 percent were using Twitter.

It was a little bit surprising, although there are definitely explanations given the state of the technological landscape, Pew researcher Aaron Smith told Reuters.

Smith said the report's authors attributed the decline in blogging to the explosion of social networking sites such as Facebook, which emphasize short status updates over personal journals.

According to the study, 73 percent of teens who were online used social networking sites.

He also cited the ubiquity of cell phones. Much of the communication between young people now takes place on mobile devices, which don't lend themselves to long-form writing.

He said teens may be shying away from Twitter because they see it as designed for celebrities, and because of reluctance to put their thoughts on such a public forum when they can post them to their Facebook page instead.

It was somewhat interesting in the sense that teens tend to be the early adopters, Smith said. They were the first to use social networking and texting. Its certainly unusual compared to what we've seen with other technology.

Blogging among adults has held steady since 2005, Pew found, but it has dropped among Internet users between the age of 18 and 29 -- while rising in those over 30.

Older people are becoming more comfortable with the online environment and young people in the meantime have moved on to social networking and text messaging, Smith said.

The teen portion of the study was based on a telephone survey of 800 people, aged 12 to 17, that was conducted from June to September of 2009.

(Editing by Vicki Allen)