WASHINGTON - Contrary to popular belief, technology is not leading to social isolation and Americans who use the Internet and mobile phones have larger and more diverse social networks, according to a new study.

"All the evidence points in one direction," said Keith Hampton, lead author of the report by the Pew Internet and American Life Project released Wednesday. "People's social worlds are enhanced by new communication technologies.

"It is a mistake to believe that Internet use and mobile phones plunge people into a spiral of isolation," said Hampton, an assistant professor of communication at the University of Pennsylvania.

The authors said key findings of the study - "Social Isolation and New Technology" - "challenge previous research and commonplace fears about the harmful social impact of new technology."

"There is a tendency by critics to blame technology first when social change occurs," Hampton said.

"This is the first research that actually explores the connection between technology use and social isolation and we find the opposite.

"It turns out that those who use the Internet and mobile phones have notable social advantages," Hampton said. "People use the technology to stay in touch and share information in ways that keep them socially active and connected to their communities."

The study found that six percent of Americans can be described as socially isolated - lacking anyone to discuss important matters with or who they consider to be "especially significant" in their life.

That figure has hardly changed since 1985, it said.

The study examined people's discussion networks - those with whom they discuss important matters - and core networks - their closest and most significant confidants.

It found that on average, the size of people's discussion networks is 12 percent larger among mobile phone users, nine percent larger for those who share photos online, and nine percent bigger for those who use instant messaging.

The diversity of people's core networks tends to be 25 percent larger for mobile phone users, 15 percent larger for basic Internet users, and even larger for frequent Internet users, those who use instant messaging, and those who share digital photos online.

At the same time, the study found that Americans' discussion networks have shrunk by about one-third since 1985 and have become less diverse because they contain fewer non-family members.

The study found that on average in a typical year, people have in-person contact with their core network ties on about 210 days.

They have mobile-phone contact on 195 days of the year, landline phone contact on 125 days and text-messaging contact on the mobile phone 125 days.

They have email contact on 72 days, instant messaging contact on 55 days, contact via social networking websites on 39 days and contact via letters or cards on eight days.

The study involved telephone interviews with 2,512 adults between July 9, 2008 and August 10, 2008 and has a sampling error of 2.1 percent.