The theory of six degrees of separation may be false. It may only be four.
According to a massive study conducted by Facebook, the social network's 800 million users—a truly titanic sampling size for research—are seperated by just four degrees. Published in a blog post titled The Anatomy Of Facebook, the results are remarkable.
We found that six degrees actually overstates the number of links between typical pairs of users: While 99.6% of all pairs of users are connected by paths with 5 degrees, 92% are connected by only four degrees.
When considering 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 we limit our analysis to a single country, be it the US, Sweden, Italy, or any other, we find that the world gets even smaller, and most pairs of people are only separated by 3 degrees.