Six degrees of separation


Many hypotheses have been verified thanks to technology, one of the most interesting is the “Six degrees of separation”. This theory was formulated in 1929 by the Hungarian writer Karinthy in the story Chains1. This theory states that each person is connected to everyone else through a chain of knowledge not exceeding 6. The first experiment to verify this was done in 1967 by the American psychologist Milgram.


Milgram randomly selected a group of Americans and asked them to send a package to a stranger who lived in Massachusetts, much far from the senders. Everyone knew the recipient’s name, but not the exact address. The senders were told to send the package to a person they knew who might have some chance of knowing the final recipient. The latter would have done the same until the package had reached its destination. A chain of hundreds of passes was expected, but the result was that on average five to six passes were made to reach the recipient.


Thanks to the help of technology, we tried to verify the theory with other experiments, the most famous is using Facebook. In fact, the social network records the links between people, ideal for testing the hypothesis of the six degrees of separation.

The experiment was carried out in 2011 by a group of computer scientists from the University of Milan in collaboration with facebook. The result? On average, the degrees of separation on the social network were 4.7. The data, however, is distorted because on social networks there are friendship relationships between people who do not know each other in real life. Other experiments have also been conducted, all of which lead to a degree of separation between 4 and 6. The theory is very important because it finds application in different fields, including the spread of diseases, the analysis of networks and the design of computers. You can have fun on this website to find the separation movies between two actors.

Happy Easter!