Finding class in the glass: Obsidian source as a costly signal

Various studies in the past have utilized a costly signaling model to understand the importance of foreign goods. With few exceptions, stone tools have been ignored in the discussion. Sourcing studies of lithic industries have often failed to acknowledge the social benefits of such trade for utilitarian objects that are also locally available with presumably lower acquisition costs. The Postclassic Aztatlán center of San Felipe Aztatán in Nayarit, Mexico is a particularly compelling case study for such an investigation. Here, both local and exotic obsidians are used abundantly, but the reason for this remains unclear. I propose that costly signaling may be the reason for the importation of these more costly lithics. To qualify this, I demonstrate that obsidian source can be easily differentiated visually with little effort despite similar appearance, making it a reliable signal of wealth and connections through visual sourcing experimentation. I then use Game Theory in the form of a Truth-Lying Game to illustrate the rational motivations for signaling as well as the deference to the presumed elevated rank of the signaler by the receiver. Through these analyses, I demonstrate the efficacy of obsidian source as a costly signal.