Is it actually 6 degrees of separation?
If you ask most people they say they have heard the fact that you can be connected to anyone in the world in 6 steps of less. That is, if given any random individual regardless of location, it should only take 6 intermediaries or edges to connect you to that person. This is one of those claims that in the past was hard to test experimentally, but with the advent of social media has made it easier to quantify and probably, as Neil Degrasse Tyson suggested, reduced 6 steps, down to 4 or 5.
Veritasium, a very popular science and thought channel on Youtube has just recently addressed this question looking at the origin of this common axiom as well as its validity. This principle was first suggested by Figures Karinthy in his writing “Chains” where he posed the challenge to find someone that he could not be connected with in 5 steps or less. The next take on this idea was done by a man named Stanley Milgram in the so called “small world experiment”. He sent out 300 packages to people who then had to get it back to him through a means other than sending it directly to him. The results of this test was an average path length of 5.2. This was the first confirmation of the 6 degrees of separation hypothesis. Although there were some flaws with the methodology. Out of all of the packages sent the majority were either sent to people living in the same town as him or in the same profession, of the packages sent to people outside those criterion only 18 made it to him.
The nature of networks also becomes relevant when seeing if 6 degrees of separation is valid. Paul Erdos looked at the nature of random networks in some detail. His findings suggested that the average number of connections to a particular node yielded some insight as to the nature of the network. It was determined that when the average number of connections is <1, the network is fragmented and has very little connectivity. However, once that number exceeds one a sort of change happens reminiscent of a phase transition from physics where any one node can be connected to another in a relatively short path length and features a high degree of connectedness. Real world networks are not random and show high levels of grouping. If you combine this grouping behavior with few random connections the average path length to any one node decreases significantly while maintaining the high degree of grouping seen in social networks. This was documented by Granovetter in his “strength of weak ties”. The weak ties are the random acquaintances and what makes the low path length possible, and therefore what makes the 6 degrees (or less) of separation possible. This is why it is also noted that you are most likely to get a job or be exposed to a new opportunity through these weak ties because in a very small number of steps the people you have access to grows exponentially.
In the ever evolving world of social media it is clear that the 6 degrees of separation will decrease. Though you may not be “friends” with all of those people on Facebook, it can be argued that one does have access to them. So in a sense the world of Facebook has just increased the number of the networks random weak ties which must serve to decrease the path length between any two nodes. In the early days of Facebook there was apparently a computer hack performed in which any time someone clicked on a page a message and that code was copied to that page. In 9 hr it reached 480 accounts, 13 hr 8880, and in 18 hr it had reached over a million accounts 1/35 of Facebook at the time; and then subsequently crashed Facebook. It is that kind of exponential growth when it comes to connection that makes it easy to see how the 6 degrees of separation are probably even less in this modern world. In a study done by Facebook they said that 92% of all its users is connected in 5 steps.
It is clear that the world is more interconnected than ever in part to the the rapid adoption all forms of social media and the internet. Even in developing countries access to the internet is more widespread than ever and is increasing. Due to the nature of networks the 6 degrees of separation is bound to decrease and perhaps already has. So the next time you here someone reference 6 degrees of separation, you can correct them and say its more like 5.
Source: Muller, Derek. [Veritasium]. (2015, August 26). The Science of 6 Degrees of Separation. Retrieved from: https://www.youtube.com/watch?v=TcxZSmzPw8k