Many years ago, a cybernetic friend told me that we are connected to any person as if by invisible threads, and that no matter how big the planet seems to us, only five other individuals separate us from the person we believe is most distant. I thought it was just another mania for representing everything with numbers and analogies; it sounded like a statement that was a bit crazy, tremendous, futuristic, but, in fact, there’s one theory, that of six degrees of separation, that's what it's called.

What is it about? It turns out that for almost a century we have had hypotheses about how easily connected we are to others. And all this before social networks, which show that we really have a lot in common with those who make up our network.

According to different sources, the concept refers to the fact that the number of acquaintances we have increases depending on the number of links we manage to reach, and that a small number of these links is enough for that set of acquaintances to become the entire human population.

That is, the theory supports this statement based on the fact that, if we calculate that each person knows approximately a hundred others, and if each of those acquaintances is related to the same number of individuals, then anyone can have access, by transitivity, to about ten thousand people through their contacts. On top of that if we continue adding, until we have the six proposed links, it would only be enough to multiply to know that the figure will increase exponentially.

It’s thought that the first time this topic was addressed was in 1929, when the Hungarian writer, Frigyes Karinthy, recreated it in a story named Láncszemek (Chains). Later, almost 40 years later, the American psychologist Stanley Milgram carried out several experiments to test the theory. And so on, many have studied it to ratify it.

However, the first assessment I had about my friend was not entirely wrong, to whom I attributed an obsession with explaining everything mathematically. I say this because an article in the journal Physical Review

In fact, let's think about social networks, Facebook, for example. It’s true that there, all the time, we find coincidences among our friends, who know someone who we thought was distant, but it was only enough for us to know the correct connection. Which represents that the world is smaller than we thought, really small, as the phrase goes.

Translated by Amilkal Labañino / CubaSí Translation Staff