Degree of separation down to 3.57

The social network has found there are on average just three and a half people between any one person and another.

It’s a theory that has been around for almost a century: There are no more than six degrees of separation between any two people on the planet.

But according to a study from Facebook, the world is actually smaller than we think. The social network has found there are on average just three and a half people between any one person and another.

Facebook analysed the hundreds of billions of connections between its users to determine a new figure for the six degrees of separation theory, which was coined by the Hungarian playwright Frigyes Karinthy in 1929 and has been extensively studied.

While Karinthy speculated that a chain of just six individuals between people can link any two on the planet, Facebook’s study suggests there are in fact just 3.57 intermediaries, or degrees of separation.

The figures only account for Facebook's membership, which stands at 1.6 billion - roughly one quarter of the world’s population.

The researchers suggested that the degrees of separation are actually shrinking as the world goes online. In 2011, when Facebook had just over a tenth of the world’s population, a study claimed there were 3.74 degrees of separation. In 2008 the number was 4.28.

The number of connections between any two people are also far lower in areas where Facebook has a higher density of users, so having more friends will mean fewer degrees of separation. In the US, there are an average of 3.47 degrees of separation.

For some, the figures are much lower: Facebook’s founder Mark Zuckerberg has 3.17 degrees and its chief operating officer Sheryl Sandberg has 2.92. The vast majority of people have between 2.9 and 4.2 degrees.

Facebook, which now has more than 1 billion people logging in every day, marks its 12th birthday last Thursday.