Continuity and Change in Islamic Ethnopharmacological Practice

This research project entailed an investigation of whether the degree of similarity between various Islamic and pre-Islamic Middle Eastern societies' overall patterns of drug plant prescription, as calculated using principles of numerical taxonomy, would correlate with the known facts of culture area morphology and the succession of intellectual traditions in the region. The attempt to quantify similarity in overall pattern is tantamount to a "cognitive dialectometry" of Islamic ethnopharmacology and its precursors, and is a first step in the development of a comparative historical approach to cognition analogous to that used in linguistics. The study considers fourteen sets of prescriptions, or "native" descriptions of medicinal attributes of drug plants, composed between 1534 B.C. and the present. For each source, patterns of grouping were identified by applying a hierarchical clustering program to a data matrix reflecting its drug plant prescription/attribute correlations. The resulting cluster trees were treated as pile sort results. Traditionally, pile sorting is a technique where cultural consultants are asked to sort items into groups based on their similarity. Shared groupings across sources were tallied, various means and functions of similarity were calculated based on sharing of groupings among sources, and degrees of overall similarity among sources were modeled using a battery of four key statistical techniques: hierarchical clustering, multidimensional scaling, k-means clustering and factor analysis. A numerical taxonomy approach to Islamic medicine shows a clear relationship between the proximity and shared history of contemporaneous localities and their overall degree of similarity in practice. It also shows that the degree of similarity between sources from different time periods correlates with the relative strength of their presumed relationships of descent and influence. The results substantiate the existence and measurability of "cognitive dialects" analogous to linguistic lects and allow for the possibility of future analyses of "cognitive creolization."