expression, noun
six degrees of separation
Refers to the hypothesis that any two people are connected by at most six social links. Often used in discussions of social networks.
六次の隔たりという考え方によれば、世界中の誰とでも六人以内の知り合いを介してつながっているらしい。
According to the idea of six degrees of separation, it seems that you are connected to anyone in the world through six or fewer acquaintances.