A third of U.S. teenagers with cellphones send more than 100 texts a day as texting has exploded to become the most popular means of communication for young people, according to new research.

The study by the Pew Internet and American Life Project, which offers a glimpse into teen culture and communication, found that texting has risen dramatically even since 2008, eclipsing cell phone calls, instant messaging, social networks -- and talking face-to-face.

The Pew Research Center said that three-fourths of young people between the ages of 12 and 17 now own cellphones and of those that do, girls typically send or receive 80 text messages per day and boys, 30 per day.

Texting is now the central hub of communication in the lives of teens today, and it has really skyrocketed in the last 18 months, Pew researcher Amanda Lenhart said, attributing the rise in part to payment plans that allow unlimited texting.

The study's authors also say that, unlike phone calls, text messaging can be quietly carried out under the noses of parents, teachers or other authority figures and, unlike computers, it can be done almost anywhere.

We've kind of hit a tipping point where now teens expect other teens to respond to text messaging and to be available, Lenhart said. There is definitely an element of text messaging that fits so seamlessly into their lives.

Text messaging has become so much a part of teenagers' lives that 87 percent of those who text said that they sleep with, or next to, their phone.

Study author Scott Campbell said focus groups conducted by Pew also offer insight into the subtleties of teen communication and culture, revealing for example that, while boys don't typically use punctuation, for girls such nuances are critical.

If a girl puts a period at the end of a text message (to another girl) then it comes across as she's mad, Campbell said, which explains the prevalence of smiley emoticons.

They have these practices because they've learned that texts can lead to misunderstandings, Lenhart said. It's a deliberate thing and it's also part of a culture that's interested in differentiating itself from adult culture.

The percentage of teens with cellphones who sent at least one text message a day increased from 38 percent in 2008 to 54 percent in September 2009, according to the study.

Meanwhile 38 percent of teens said they daily make at least one cell phone call, 30 percent said they talk on a landline phone and 24 percent said they used instant messaging.

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