Six Degrees of Separation? Try Three

Facebook Data Science calculates just how connected the world really is.

The world is getting pretty small these days. In the 90's, it was once posited that every movie star on Earth could be connected to Kevin Bacon within six degrees. Since that time, the internet has shown us that this is probably the case with every person on Earth (I myself have a Bacon Number of 2). Now, according to a new blog post on Facebook's research arm, being separated by two degrees from anybody on Earth is not unheard of.

They say that as more and more users are using the ubiquitous social media platform, these degrees of separation have been steadily shrinking.

In 2011, researchers at Cornell, the Università degli Studi di Milano, and Facebook computed the average across the 721 million people using the site then, and found that it was 3.74 [4,5]. Now, with twice as many people using the site, we've grown more interconnected, thus shortening the distance between any two people in the world.

Their most recent calculation put the mean separation between any given person to another is 3.57 degrees. If that sounds hard to believe, think of it this way: If you have 100 friends, and each of your friends has 100 friends, that's already 10,000 friends of friends. Calculating the degrees for each of the 1.6 billion users on Facebook takes a lot of computing power. Heck, I can usually only remember, like, three names at any given time.

Rather than calculate it exactly, we relied on statistical algorithms developed by Kang and others [6-8] to estimate distances with great accuracy, basically finding the approximate number of people within 1, 2, 3 (and so on) hops away from a source.

The final result is this graph.

Figure 1. Estimated average degrees of separation between all people on Facebook. The average person is connected to every other person by an average of 3.57 steps. The majority of people have an average between 3 and 4 steps.Facebook Research https://research.facebook.com/blog/three-and-a-half-degrees-of-separation/

How small is your world? You can find out your own number at Facebook's blog post on the subject here.

Hat tip to Nicola Black for sending me the link