"Six Degrees of Separation" refers the theory that any person on Earth can be connected to any other person through a chain of no more than five other people.
The theory was first mentioned in the 1920s by the Hungarian author Frigyes Karinthy discussed social networks. In the 1950s, an attempt (make) by two scientists to prove the (theory) idea. However, they were unsuccessful. In 1967, Stanley Milgram tried using a new method to test the theory. He (random) chose a sample of people in the middle of America (send) packages to a stranger. Amazingly, only took between five and seven people to get the parcels (deliver). It was this research that inspired the phrase "Six Degrees of Separation".
In the last few decades, the theory and the phrase have appeared again. Its name was used as the title of a play and then a film. In 2003, Columbia University tried to recreate Milgram's experiment on the Internet. In 2011, an experiment at the University of Milan analysed relationship between 721 million social media users and (find) that 92 percent were connected by only four stages, or five degrees of separation.
