We have postulated five major stages by which the culture- history of aboriginal America may be recounted. These stages are sequential and are derived from an inspection of archaeological sequences throughout the hemisphere. Certain criteria were selected for generalization from a detailed examination of numerous local and regional sequences. The method is comparative, and the resulting definitions are abstractions which describe culture change through time in native America. The stages are not formulations which explain culture change. Explanation, we believe, lies in the complex interplay of the multiple factors of natural environment, population densities and groupings, group and individual psychologies, and culture itself. Our culture-stage constructs are fashioned for the infinitely simpler purpose of describing types of cultures and the arrangement of these types in sequential order in the various parts of the New World.
Our earliest stage, the Lithic, is characterized by chipped-stone tools and weapons. These artifacts are found in environmental contexts of the late Pleistocene, under conditions indicating a climate quite different from that of the present and often with remains of extinct fauna. We have suggested the possibility of a major division within this Lithic stage, an earlier era featuring crude percussion-flaked choppers and scrapers and a later era in which stone-chipping was much more finely finished and in which lanceolate point forms were a diagnostic. As yet, however, the evidence for such a division is not conclusive. In general, it is believed that the period of the Lithic stage ranged from perhaps as early