The Internet is evolving, and teenage girls are leading the charge, according to a new report by the Pew Internet & American Life Project.

More than nine out of 10 teenagers are online, according to the report, and “more of them than ever are treating it as a venue for social interaction — a place where they can share creations, tell stories, and interact with others.”

The trend is especially popular among teenage girls, who are fast becoming the new voice of the Web 2.0 era.

Girls between the ages of 12 and 17 are more likely than any other group to produce most types of online content, the study found. They are more likely to create a Web page, to start a blog and to create accounts on social networking sites like MySpace.

“Girls definitely do it more,” said Vintage High School sophomore Tanya Fregoso, 15, who created her own photography Web site this summer. “Most boys don’t even have a simple ‘Hi, my name is’ on MySpace. Girls can rant and rant and rant. … It’s just easier for girls to talk and open up about random things.”

Since 2004, teen girls have outpaced boys in Web site contributions, with 32 percent of teen girls who are online creating or working on their own Web pages, compared with 22 percent of boys, said the report. Only 14 percent of adults build their own Web pages, it said.

The study found that 35 percent of online teen girls blog, compared with 20 percent of online boys.

Seventy percent of girls between 15 and 17 years old who use the Internet have created accounts with online social networks like MySpace or Facebook, the report said, as opposed to only 57 percent of boys.

“Guys are usually just like, “Uh, I’m just going to use (MySpace) to talk to hot girls,” said Fregoso. Girls are more likely to discuss the details of their family lives, school and personal relationships, she said.

Clinical psychologist Dr. Dan Peters, who practices in Napa and San Ramon, said the virtual gender gap can be traced back to the basic differences between men and women.

“Females are more into interpersonal connection, communication and are better at expressing their thoughts and feelings generally than males,” he said. “Within the teenage culture, obviously the Internet has become a primary mode of communication and affiliation. It’s no surprise that female teenagers would gravitate toward that modality of connecting, expressing themselves and sharing their feelings.”

Teenage boys do dominate one area, said the report. Online teen boys are nearly twice as likely as girls to post videos on sites like YouTube, with 19 percent of boys sharing videos, as compared to 10 percent of girls and eight percent of adults.

Joe Manthey, who will lead a workshop in Napa this month about educating boys, said the neurological explanation for this break from the trend is that boys are generally more spatial — meaning more inclined to watch or manipulate objects — than girls, who are more verbal and emotive.

For teens, content creation is not just about sharing creative output, said the report. It is about starting a dialogue “fueled by that content.”

“Digital images — stills and videos — have a big role in teen life,” it said. “Posting them often starts a virtual conversation.” Almost 90 percent of teens who post photos for others to see say that people comment on those images at least “some of the time,” said the report. Three-quarters of teens reported commenting on blog posts written by others.

Fregoso said feedback is crucial to the success of her Web site, where she posts her own photography.

“You find out, maybe people will like this one, maybe this affects somebody,” she said.

According to the report, 95 percent of teenage girls participate several times a week in at least one activity related to communication, as do 84 percent of boys.

Phone conversations and face-to-face meetings are still the most frequent forms of communication for teenagers, the report said, but “communications patterns among teens are shifting as their array of options grows.”

This increase in screen time doesn’t necessarily come at the expense of other activities, said the report. “In fact, in many cases, those who are the most active online with social media applications like blogging and social networking also tend to be the most involved with offline activities like sports, music, or part-time employment,” the report said.