عنوان مقاله [English]
The present study examines the possible relationship between language, geography and the mobility of human populations at macro-level and proposes that the linguistic makeup of the Iranian plateau is shaped by the interplay between three factors: a geographic, a demogrpahic and a linguistic factor. The geographic factor (=ecological+topographic) shapes demographic features (=population mobility vs. sedentarism) by attracting populations to fertile lands vs. sending them off from hostile environments. The Iranian plateau is a vast land with a discrete topography; two features that reduce the possibility of communication between the languages of periphery, while at the same time put them in constant, longterm contact with the lingua franca of the plateau, contemporarily Persian and historically Pahlavi. As a result, the contact component of the linguistic factor (contact vs. isolation) is also determined by geographical and demographic factors at macro-level. This situation brings about what we have dubbed “±communicational accumulation.”, which in turn fascilitates convergence or divergence between different historical and/or geographical dialects. This constant cycle necessitates the existence of a common linguistic variety shared by various ethnicities acrossc the Iranian plateau, that is, the rise of either a lingua franca or a koiné out of local varieties. Iranian plateau has thus witnessed the birth of a lingua franca roughly at its center, spreading toward the multilingual peripheries.