six degrees of separation
Six degrees of separation is the theory that anyone on the planet can be connected to any other person on the planet through a chain of acquaintances that has no more than five intermediaries. The theory was first proposed in 1929 by the Hungarian writer Frigyes Karinthy in a short story called "Chains."
Although the participants expected the chain to include at least a hundred intermediaries, it only took (on average) between five and seven intermediaries to get each package delivered. Milgram's findings were published in Psychology Today and inspired the phrase "six degrees of separation."
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