In 1929, Hungarian author Frigyes Karinthy wrote the short story Chains, containing a concept you’re probably familiar with thanks to the star of My Dog Skip and Footloose.
In the story, a group is chatting when the narrator has a minor revelation about how the world has shrunk due to quickening communication and transport. During the discussion, they decide to play a game: they would choose one person out of the 1.8 billion people on the planet (at the time), and would try to figure out if they could contact them using no more than five people in a chain.
Again and again they find that they can do it, without ever needing a sixth person. The idea – now referred to as the six degrees of separation – is that anyone on Earth is connected to anyone else by a chain of acquaintances no longer than six people. You may know the concept from the updated game Six Degrees of Kevin Bacon, in which someone names an actor and you must link them to Kevin Bacon in five moves or fewer.
In 2016, Facebook research found that there are in fact on average 4.57 degrees of separation between people using the social network site and any other individual on the platform. So why does it take so few steps to get from one person to any other on the planet? A recent study claims that it’s due to how we construct our social networks, and how much effort they take to maintain.
According to the team, six degrees of separation results from people attempting to widen their networks and form connections that may benefit them.
The team goes through a game where at each step an agent (or human) can decide whether it is more profitable to gamble and form connections with other “nodes” outside of their own, or to remain in their current situation. Costs are applied, to replicate how real life connections have costs too (think how in order to stay friends with Jeff, you sometimes have to pretend you enjoy his horrible music). Agents were assumed to want to increase their own importance within their networks, and act to improve their situation. Allowing these networks to evolve, they got a surprise.
“We theorematically prove that any network where nodes strive to increase their centrality by forming connections if and only if their cost is smaller than the payoff tends to evolve into an ultrasmall-world state endowed with the six degree of separation property, irrespective of its initial structure,” the team wrote in their paper.
“We need to understand that each individual in the network acts independently, without any knowledge or intention about the network as a whole,” one of the llead authors, Professor Baruch Barzel, added to The Jerusalem Post, “but nevertheless, this self-driven game shapes the structure of the entire network. It leads to the small world phenomenon, and to the recurring pattern of six degrees.”
The study is published in Physical Review X.
Source Link: The 6 Degrees Of Separation Finally Gets An Explanation
