Bloggers Make Buddies Close to Home, Research Shows

Stefan Lovgren
for National Geographic News

August 2, 2005

It's a small world—even online, as social researchers have discovered.

In a recent study, scientists observed members of the online community LiveJournal.com, to track how relationships form in cyberspace. The researchers found that, even with the world at their fingertips, most users tend to select friends from their own geographical areas.

With more than 500,000 users in the United States, LiveJournal is a popular Web forum that allows its users to create and customize their own online diaries.

One of LiveJournal's features is a "friends" page that enables users to view journal updates of people they have chosen as their online friends.

When researchers examined the profiles of journal keepers, they discovered that users tended to form friendships in cyberspace with people who lived near them in the real world.

"People tend to make friends according to a particular pattern, based on the geography of their friends," said Andrew Tomkins, a research scientist at Yahoo! in Sunnyvale, California.

This tendency to make virtual friends based on geography also creates the so-called small world phenomenon, in which strangers learn that they share several acquaintances. "This pattern that people somehow happen to adopt is the only way to form small worlds," Tomkins said.

Tomkins co-authored the LiveJournal study, which is reported this week in the Proceedings of the National Academies of Science.

Blogs and Buddy Lists

Previous experiments have shown social networks to be "navigable small worlds" in which a person can transmit a message to another random person through a short chain of friends.

The concept gave rise to the famous phrase "six degrees of separation," after a 1967 small-world experiment by the social psychologist Stanley Milgram. His study found that two random U.S. citizens were connected by an average of six acquaintances.

Studies have shown that in online communities, two strangers can usually find a connection with only a few degrees of separation.

Social-network research is of growing interest to Web developers, as the Internet moves from being an informational medium to a social forum filled with blogs, buddy lists, and instant messages.

Researchers are keen to develop models to explain the small-world phenomenon.

"The goal of our research was to try to understand what makes our world small," said David Liben-Nowell, a study co-author and computer science professor at Carleton College in Northfield, Minnesota. "We were trying to understand something about the why of the small-world phenomenon in a real network."

LiveJournal provided an ideal opportunity to study the friendship networks that people form, because the site allowed researchers to easily gather information about its users, including their interests, friends, and geographic locations.

"It became clear that geography was playing a major role in what was going on in the network," Liben-Nowell said. "Geography alone is essentially enough to explain why we live in a small world."

"If I have a message that I desperately need to pass along to [U.S. Vice President] Dick Cheney via a chain of intermediate friends, then it's a pretty good idea for me to initially send it to my high-school classmate Beth, just because she works in Washington, D.C.," he added.

From Idaho to Manhattan

The researchers found that in two-thirds of the friendships on LiveJournal, the friends shared a close geographic proximity. The other third of the relationships were "nongeographic," with friendships forming regardless of the distance between people.

Previous research has shown that friendships tend to decrease with distance. But the new study shows that the tendency also depends on population density.

Members living a mile apart would more likely be friends if they lived in Idaho than in Manhattan, researchers said.

"Consider my chances of being friends with a particular person—call him Bill," Tomkins said. "Draw a circle on the map, centered at me, with Bill on the outer edge. It's natural to think that my chances of being friends with Bill depend on how big the circle is, but that's wrong. Instead, it depends on how many people are in the circle."

The proper combination of distance between friends and density among them results in a "small world" phenomenon, the researcher added.

"If people make friends according to this [geographically] rank-based friendship, then short paths will magically emerge in the network, and people will be able to find them once they are forwarding messages," Tomkins said.

"But if you deviate a little bit from the formula—if you have too many [nearby] friends or too few [nearby] friends—then suddenly you won't have those short paths anymore and the network will become very difficult to navigate," he said.

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