Six Degrees of Separation? Facebook Finds a Smaller Number - The New York Times

Check this Facebook post for the research project details

"The new statistic is as much a testament to the growing popularity of Facebook as it is to a steadily shrinking human social world. The calculation includes only connections between the network’s 1.59 billion users, ignoring the approximately 5.7 billion other humans who have yet to set up accounts. (In July, the United Nations estimated that the current world population to be 7.3 billion.)

If you are logged into Facebook, the blog post will tell you your average degree of separation “from everyone.” The number is an estimate derived from statistical algorithms and not, as it seems, an intrusive estimate of the reach of your friends and family. According to the post, Facebook users in the United States are connected by an average of 3.46 people."

Six Degrees of Separation? Facebook Finds a Smaller Number - The New York Times