The Personal Networks and Community Survey is the first to examine this issue. It found that the amount of "severe isolation" has hardly changed since a previous study, which was conducted in 1985 before these technologies emerged. About six percent of adults, roughly the same as in 1985, report they have no one in their life that they consider "especially significant" and with whom they can discuss important issues in their lives.

Larger Discussion Networks

The study found that Internet-based activities and cell-phone ownership led to "larger and more diverse" discussion networks. And the use of social media is more likely to lead to discussion networks among people from different backgrounds, such as those of another race or a member of another political party. Facebook and blog writing were specifically cited as helping a person have a more diverse social network .

In spite of worries that using a global Internet would tend to limit people's local activities, the study found little or no such impact. Internet users, for instance, are as likely to visit neighbors as non-Internet users, and cell-phone users, people who use the Internet often at work, and bloggers are more likely to belong to a young group, a charitable organization, and the like.

Some kinds of social networking , such as MySpace or Facebook, have become a kind of neighborhood involvement, according to Pew. Any frequent Facebook user, for instance, can describe using the service to keep up with friends, even if they live nearby. In fact, the Internet is used as much for contact with people in one's local community as with people far away.

'Expand People's Social Sphere'

Pew also said the Internet doesn't discourage people from going to public places, like parks, cafes and restaurants, where a more diverse social network can be found. In fact, many public places, such as libraries and some coffee shops, now offer Internet access.

Next to in-person contact, contact by mobile phone is already the second most popular way of staying in touch with friends and family. In order of average frequency of contact with one's core network, in-person contact is 210 days annually, contact over mobile phones is 195 days, and landline is 125. Other means, in descending order, are text messaging, e-mail, instant messaging, contact through social-networking sites, and cards or letters.

Michael Gartenberg, a vice president at industry research firm Interpret Research, wasn't surprised by the survey's results. Internet-based social media, he pointed out, are intended to "expand people's social sphere," and they often end up helping users to "reconnect to people with whom they might have lost touch."

At this point in history, he noted, "we have an unprecedented ability to communicate with people in real time, anywhere on the planet, from any place we are," and we have tremendous capabilities to extend our social presence beyond the physical. Gartenberg said the bottom line is that "we're in uncharted territory."

The Pew study was based on telephone interviews of a nationally representative sample of 2,512 adults in the continental U.S., using a combination of landline and cellular random dialing.