Dec. 5, 2011 -- Two new studies suggest that sexting among teens may not be as common as many people think it is.
In the first study, researchers from the University of New Hampshire Crimes Against Children Research Center in Durham telephone-surveyed more than 1,500 Internet users between the ages of 10 and 17, asking whether they engaged in creating, sending or delivering sexually explicit images or videos either through their mobile phones or the Internet.
The study, published in the journal Pediatrics, found that 2.5 percent of the young people surveyed participated in some sort of sexting activity in the past year, but only 1 percent admitted activity that included material considered child pornography, meaning images or videos that featured naked genitals, breasts or buttocks.
But if the definition of sexting is broadened to include sexually suggestive images, such as provocative poses with no nudity or appearing almost nude, the number of kids participating in it jumps to nearly 10 percent. Most kids participate in sexting either as a prank or while they're in a relationship.
"One of the takeaway messages is it's good news," said co-author Kimberly Mitchell. "It's reassuring that it's not as prevalent as we thought in past research." Mitchell, also a research associate professor of psychology, said her study is the first one to break down the types of images by the degree of sexual explicitness.
Data Vary on Prevalence of Sexting
Previous research has yielded very different data on teen sexting.
A 2009 survey by the nonprofit group National Campaign to Prevent Teen and Unplanned Pregnancy found that 20 percent of teens ages 13 to 19 sent or posted sexually suggestive photos or video of themselves.
But another survey done that same year by the Pew Research Center found that 4 percent of teens between the ages of 12 and 17 who own mobile phones said they sent nude or almost nude images or videos of themselves, and 15 percent of teens said they received these types of images and videos.
Research presented early last month at the American Public Health Association's annual meeting found that 10 percent of nearly 23,000 Boston-area high school students said they sent a sext message in the past year, and 5 percent said they received a sexually suggestive image.
Dr. Michael Rich, an associate professor of pediatrics at Harvard Medical School told ABC News in November that the number of teens who sext seems to be dropping, possibly because they are more aware of the consequences of their behavior.
"In other words, their awareness of the risk is now increased," he said.
The researchers urge better assessment of what's involved in sexting, because they believe it is not an example of extreme risk-taking or sexual behavior.
"Sexting has been greeted in many media portrayals as yet another sign of the hypersexualization of youth and extreme risk-taking," the authors wrote. "In fact, however, many indicators of youth sexual behavior such as teenage pregnancy and the number of young people with multiple sexual partners have been improving in recent years, in spite of such concerns."
In a separate study, Mitchell and her colleagues also found that in 2008 and 2009, law enforcement officials across the country investigated about 3,500 cases of sexual images created by teens. Of these cases, most arrests occurred in cases in which sexting violated child pornography laws or when there was another crime involved, such as blackmail or harassment. More than 80 percent of the images remained on mobile phones and did not end up online.
"We need to look at these on a case by case basis since there are such a variety of images," Mitchell said. A lot of the behavior, she explained, is merely the result of adolescent experimentation or curiosity. In general, arrests aren't the norm unless there are adults involved in the sexting.
Regardless of the observed decline in sexting among youth and the fact that a lot of the behavior may only be sexual experimentation, Mitchell emphasized that young people need to be aware of the risks involved with the exchange of sexually suggestive material.
"It's important for teens to be aware of what they're doing," Mitchell said. "Because of the nature of technology, they can't expect it to stay with the person they send it to. It can be circulated and can be embarrassing." In some cases, it can be treated as a crime, so young people should be aware of those repercussions as well.
It can also be emotionally devastating. In the study of the Boston-area high school students, researchers found that students involved in sexting were more likely to report attempting suicide and were twice as likely to report depressive symptoms.
ABC News' Christina Caron contributed reporting to this story.