Six Degrees of Separation Now Five, Thanks To Facebook

Facebook and the University of Milan have determined that the social-networking giant has reduced the degrees of separation between any two people in the world from six to about less than five -- and even fewer when people live in the same nation. The research continues psychologist Stanley Milgram's "small world experiment" from the 1960s that explored the structure of social networks.

Facebook and university researchers first measured how many Facebook friends people have. The distribution is much different than in past large-scale social network studies. The researchers also discovered that the degrees of separation between any two Facebook users is smaller than the traditional six degrees theory. In fact, it has been shrinking over the past three years as Facebook has grown.

The overarching conclusion: The entire world is only a few degrees away but a Facebook user's friends are most likely to be similar in age and from the same country. But does anybody really care?

Does It Matter?

"Social networks are tying people together or exposing the fact that people are more closely connected than perhaps we all thought. It's a bit of a surprise how closely connected, actually," said Greg Sterling, principal analyst at Sterling Market Intelligence. "Now if Facebook could only help solve political and social problems like budget crises, climate change or global poverty."

Sterling makes a relevant point. Although the Facebook-University of Milan study is the largest social network study ever released -- researchers examined all 721 million active Facebook users, which is more than 10 percent of the entire world population -- the results are interesting but not altogether significant in the immediate term.

But could it be possible that these interconnections could have an impact in the future? Perhaps. According to Facebook, for even the most distant Facebook user in the Siberian tundra or the Peruvian rainforest, a friend of your friend probably knows a friend of their friend. When the analysis is limited to a single country, the world gets even smaller. Most pairs of people are only separated by three degrees.

"It's easy for me to imagine that a path from me to a random person in Siberia goes first to one of my few Russian friends in California, and then hops around the globe to a friend of theirs living in Russia," Facebook said in the study report. "But, while I can imagine these short paths connecting all pairs of people in the world, this notion stands in sharp contrast to my day-to-day experience. Most of my friends live in the U.S., and the ones I am closest to live within just a few miles of me."

Contrasting Degrees

The study does highlight another interesting aspect of modern technology. Facebook concluded that social networks are both well-connected in the sense that you can reach anyone from anyone else in a relatively short number of hops, but at the same time, they are very locally clustered, with the vast majority of connections spanning a short distance.

"In our study, we found that 84 percent of all connections are between users in the same country. But this isn't the only dimension along which people tend to cluster," the report said. "We also find that people tend to have a similar, albeit typically smaller, number of friends as their neighbors, and tend to be about the same age. Somewhat surprisingly, even for individuals aged 60, the distribution of their friends' ages is sharply peaked at exactly 60."