You’re familiar with the “Six Degrees of Separation” concept–that any two people are no more than six acquaintance links apart. A knows B, who works with C, who is related to D, who lives in the same town as E, who attends church with F. The idea actually traces back to a short story by a Hungarian author in 1929.
In the 1960s, a study asked 296 volunteers to send a message to a specific person living in Sharon, Mass., routing it through personal acquaintances. The average number of “hops” was 5.2, which pretty much confirmed the whole “six degrees” thing (with no Kevin Bacon involved).
Facebook developed some algorithms to test the theory with Facebook users. They found that the average distance between users, worldwide, was 5.3 hops in 2008. With the growth in number of Facebook users, it had dropped to 4.7 hops by 2011. That’s on a global scale. When limiting persons to a single country, the average was just 4 hops.
