Jewish geography is a popular "game

Game

A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...

" sometimes played when Jews

Jews

The Jews , also known as the Jewish people, are a nation and ethnoreligious group originating in the Israelites or Hebrews of the Ancient Near East. The Jewish ethnicity, nationality, and religion are strongly interrelated, as Judaism is the traditional faith of the Jewish nation...

 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

Norm (sociology)

Social norms are the accepted behaviors within a society or group. This sociological and social psychological term has been defined as "the rules that a group uses for appropriate and inappropriate values, beliefs, attitudes and behaviors. These rules may be explicit or implicit...

 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

Book

A book is a set or collection of written, printed, illustrated, or blank sheets, made of hot lava, paper, parchment, or other materials, usually fastened together to hinge at one side. A single sheet within a book is called a leaf or leaflet, and each side of a leaf is called a page...

 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 [insert name of city here]? Do you know [insert person's name here]?" 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. [p. xv].

Sonia Pressman Fuentes

Sonia Pressman Fuentes

Sonia Pressman Fuentes is an American author, speaker, feminist leader and lawyer. She was born in Berlin, Germany, of Polish parents, with whom she came to the U.S. to escape the Holocaust. In the U.S., she became one of the founders of the second wave of the women’s movement...

 describes it in her memoir

Memoir

A memoir , is a literary genre, forming a subclass of autobiography – although the terms 'memoir' and 'autobiography' are almost interchangeable. Memoir is autobiographical writing, but not all autobiographical writing follows the criteria for memoir set out below...

  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."

Origins

The origins of "Jewish Geography" are unclear. An Israeli version of the game, pitsuchim, has been a common pastime among young Israeli backpackers traveling the world, taking its name form a 1980s television quiz show. As to the origins of Jewish Geography itself, Sarah Benor, a linguist and professor of Jewish Studies at Hebrew Union College has noted "Sometimes that kind of thing is really impossible to find."

Analysis

The term "Jewish geography" not only functions as the name of the game, but also describes the unique smallness and closeness of the worldwide Jewish population

Population

A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...

. The Jewish population's "Jewish geography," therefore, is what makes the game possible and lets Jews from different cities, regions, and countries easily discover people they know in common.

Both the game and the concept are Jewish-specific examples of the six degrees of separation

Six degrees of separation

Six degrees of separation refers to the idea that everyone is on average approximately six steps away, by way of introduction, from any other person on Earth, so that a chain of, "a friend of a friend" statements can be made, on average, to connect any two people in six steps or fewer...

 theory

Theory

The English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...

 proposed by Hungarian writer Frigyes Karinthy

Frigyes Karinthy

Frigyes Karinthy was a Hungarian author, playwright, poet, journalist, and translator. He was the first proponent of the six degrees of separation concept, in his 1929 short story, Chains . Karinthy remains one of the most popular Hungarian writers...

 in 1929 and the small world phenomenon hypothesized by social scientist Stanley Milgram

Stanley Milgram

Stanley Milgram was an American social psychologist most notable for his controversial study known as the Milgram Experiment. The study was conducted in the 1960s during Milgram's professorship at Yale...

in 1967.

While the accuracy of these theories have been questioned by some, few Jews doubt the validity of "Jewish geography," having observed its connective power firsthand.

The phenomenon can be observed in other groups of common interest and cultures, including Bahá'ís, Mormons (members of The Church of Jesus Christ of Latter-day Saints) and Jehovah's Witnesses.