Facebook Finds Just 3.5 Degrees of Separation Between Users

facebook six degrees of separation mark zuckerberg
Facebook CEO Mark Zuckerberg in front of a visualization of the social network at the company's F8 conference in California, September 22, 2011. New research suggests each person in the world is connected to every other person by an average of three and a half people. Robert Galbraith/ Reuters

The theory that every person is connected to every other person on the planet by six degrees of separation has been debunked by new research from Facebook.

The social network determined that the figure is in fact almost half that, with each of its users connected to every other user by an average of three and a half people.

The idea that everyone is connected to any other person in the world through a friend-of-a-friend chain in a maximum of six steps was first set out by the Hungarian author Frigyes Karinthy in 1929.

Several studies have since been conducted to put this theory to the test, however it is only since the advent of the Internet and social network sites that it can be explored on a significant scale.

Facebook's research drew upon its 1.59 billion active users to find that people within the U.S. are connected to each other by an average of 3.46 degrees of separation, while the global average is 3.57 degrees.

A similar study in 2011 found that across the 721 million people who were using Facebook at the time, the average was 3.74.

"This is a significant reflection of how closely connected the world has become," Facebook said. "When people connect, powerful things happen and lives are changed.

"We see this on Facebook every other day, whether it's an exchange with an old friend that brings a smile to your face or a new connection that changes your life path, or even the world."