Jewish Geography

Jewish geography is a popular "game" sometimes played when Jews meet each other for the first time and try to identify people they know in common. The game has become something of an informal social custom in the Jewish community, and it's often surprisingly easy for strangers who play it to discover mutual acquaintances and establish instant context and connection.

As Etan Diamond observes in his book And I Will Dwell in Their Midst: Orthodox Jews in Suburbia:

This "game" of "Jewish geography" follows a simple pattern. One person asks, "You're from ? Do you know ?" The other one usually responds something like, "Sure, he sits behind my uncle in synagogue," or "I met her once at a youth group convention," or "She is really good friends with my sister's college roommate." Non-Jews often find it astonishing that such links are made so easily, but given both the relative smallness of the Jewish community - and the even smaller size of the Orthodox Jewish community - and the extensive overlapping social circles within these communities, it should not surprise too much. .

Sonia Pressman Fuentes describes it in her memoir Eat First - You Don't Know What They'll Give You: The Adventures of an Immigrant Family and Their Feminist Daughter, "... When two or more Jews meet who share a connection to a particular ... locality ... they will question each other until they find that they know, or know of, at least one other Jew in common."