ABSTRACT
To say that a problem is treated in an interdisciplinary fashion can mean a number of different things, depending on the exact point in the process of inquiry at which interdisciplinary thinking is introduced. The small world problem is a relatively new topic of investigation, and thus has not yet been "claimed" as the exclusive property of any one discipline. Concern with the small world problem is not new, nor is it limited to social psychologists. Social communication is sometimes restricted less by physical distance than by social distance. Graph theory, which is concerned with the mathematical treatment of networks, provides a convenient way of representing the structure of acquaintanceships. It is a fairly straightforward job to check up on the amount of inbreeding using one or two circles of acquaintances, but it becomes almost impossible when the acquaintance chain stretches far and wide. Geographic movement from the state of Nebraska to Massachusetts is striking over the several links.
