We take a look at the well-known theory of ‘Six Degrees of Separation’. Down the years this has been something of a cultural phenomenon, with the theory attracting mass interest and heated debate. The theory proposes that everyone on Planet Earth are six (or less) steps away from every other person in the world, based on their connections. This brings the idea of a ‘friend of a friend’ to life. So what does the statistics and data suggest – is it a theory that has much credence attached, or is it wrong?
To begin with a history – the theory was originally set out by Hungarian author Frigyes Karinthy, who posited the theory in the 1920s. The theory entered popular culture in the 1990s after a play written by John Guare featured the idea. Since the play, there have been questions raised over the theory, and efforts made to test the validity of the theory. Here are some key landmarks in recent times of the theory:
After World War One
It was believed that following the bloodshed of World War One, that the world was ‘shrinking’. Rapid technological advancements made humans closer, with improvements in infrastructure and logistics enabling the world to run smoothly. Communication improved strongly.
As will become clear, Columbia University showed a profound interest in the theory in the early 2000s. Professor Duncan Watts used the Internet to test the theory out. He used citizens from 157 countries to conduct a test. His test results found that indeed six steps was the most-common amount between people. This helped to add weight to the theory, though his compatriots at the University would question it, just two years later…
Columbia University Project
The second effort from Columbia University came in 2003, as they conducted an experiment using the Internet. They used email to try and put the theory into practice. The group behind the experiment set a target of reaching 18 pre-selected people across 13 different nations. Despite 100,000 people entering, a minimal amount of targets were made. The conclusion drawn from the experiment was that the theory was incorrect.
Four years later some of the folks at Microsoft Messenger decided to do their own experiments. Jure Leskovec and Eric Horvitz examined 30 billion conversations from instant messages, emanating from 240 million people. This large study reached the conclusion that the average path length was indeed six. Of all the numbers! This added considerable weight to the argument.
The theory re-entered popular culture through media personality Kevin Bacon. A game where the player would attempt to link Bacon through no more than six connections to another actor was created. The player would need to find co-stars of Bacon in any of his films. Google also joined in the fun, helping to facilitate even more interest in the game.
There is very little that can be done to explicitly suggest whether or not this theory is correct. The common saying of ‘it’s a small world’ comes into this argument. Sometimes it can just be a coincidence, but the data presented here is quite alarming. The Microsoft Messenger study was the biggest of its kind, and provided evidence to suggest that the theory is correct. On social media it can be common to find a ‘random’ person, yet find you have mutual friends. All of this means that you are technically just six steps away from anyone – even US President Donald Trump! While this phenomenon will surely continue to raise questions, it does appear to be true. The world continues to amaze.