A Twitter page is displayed on an Apple iPhone in Los Angeles October 13, 2009.

NEW YORK - Contrary to popular belief, the Internet and mobile phones are not isolating people but enhancing their social worlds, according to a U.S. survey.

The survey was sparked by a 2006 study by U.S. sociologists who argued technology is advancing a trend seen since 1985 -- Americans becoming more socially isolated, their social networks shrinking, and the diversity of their contacts decreasing.

But the study by the Pew Internet and American Life Project, titled "Social Isolation and New Technology," found people's use of mobile phones and the Internet is actually associated with larger and more diverse social networks.

"When we examine people's full personal network... Internet use in general and use of social networking services such as Facebook in particular are associated with more diverse social networks," the researchers said in a statement.

"Our key findings challenge previous research and commonplace fears about the harmful social impact of new technology."

The telephone survey of 2,512 adults, conducted by Princeton Survey Research International in July and August this year, found that since 1985, the extent of social isolation has hardly changed at all.

It found 6 percent of the adult population has no one with whom to discuss important matters but this figure is largely unchanged since 1985.

The survey, however, did find that people's "discussion networks" have shrunk about a third in the past 25 years and become less diverse as they contain fewer non-family members.

But people who have mobile phones and take part in a variety of Internet activities are associated with larger, more diverse core discussion networks.

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, instant messagers, and those sharing photos online.

Internet users were as likely as anyone else to visit their neighbors and take part in local community activities.

"Cell phone users, those who use the Internet frequently at work, and bloggers are more likely to belong to a local voluntary association, such as a youth group or a charitable organization," the study found.

"However, we find some evidence that use of social networking services (e.g., Facebook, MySpace, LinkedIn) substitutes for some neighborhood involvement."

The researchers said most uses of the Internet and mobile phone have a positive relationship to neighborhood networks, voluntary associations, and use of public spaces.

"Our survey results suggest that people's lives are likely to be enhanced by participation with new communication technologies, rather than by fearing that their use of new technology will send them into a spiral of isolation," they concluded.