“Six Degrees of Separation” is a theory that suggests any two people on Earth are, on average, about six acquaintances apart, or in other words, a chain of “a friend of a friend” statements can connect any two people in six steps or fewer. This concept came to light in 1929 by Frigyes Karinthy and later gained popularity through Stanley Milgram’s experiments in the 1960s. It has since influenced popular culture, online platforms, and even mathematical models. Significant studies and services, such as the Columbia Small World Project and Six Degrees of Wikipedia, have further explored and applied this idea. It has profound implications in understanding human interconnectedness, social networks, and psychology.
Six degrees of separation is the idea that all people are six or fewer social connections away from each other. As a result, a chain of "friend of a friend" statements can be made to connect any two people in a maximum of six steps. It is also known as the six handshakes rule.
The concept was originally set out in a 1929 short story by Frigyes Karinthy, in which a group of people play a game of trying to connect any person in the world to themselves by a chain of five others. It was popularized in John Guare's 1990 play Six Degrees of Separation.
The idea is sometimes generalized to the average social distance being logarithmic in the size of the population.
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