Let us begin first with the historic and prehistoric culture classifications. Our experience with Old World archæology arouses two expectations. In classical problems, we anticipate finding a long and continuous occupation of definite areas where we find the successive remains of what is, in its fundamentals, a single expanding culture. As all of these areas have well-established historical periods, we take, as a matter of course, the close correlation, or superposition, of archæological and historical culture localizations. On the other hand, when we deal with the archaeology of cultures that do not readily connect themselves with historical data, as the Paleolithic cultures of western Europe, and even some of the Neolithic, we are accustomed to find a series of cultures resting one above the other, but between which the connections are broken. It has sometimes been proposed that this difference is, in the main, one of interpretation, but again it is defended as a real difference due to the relative antiquities of the two groups. Thus, it is considered that cultures arising early enough to run their courses before the dawn of history, have time to vanish completely and leave room for the establishment of something entirely new and independent. Without dwelling upon the respective merits of these two somewhat opposing views, we may turn to the objective correlation of the archæological and cultural classifications for the New World.
In the first place, the reader should fix in his mind the nature of these distribution areas. Our analyses show that each is a more or less illy-defined area in which there are many trait differences, but that these show a gradation outward from a center, or nucleus. While, by comparative study, one arrives at the generalization of a type for the various social groups making up such a center, the result is, nevertheless, strongly grounded in empirical methods, and is not the work or interpretation of a single individual. We have seen that in this respect the historic and archæological areas are essentially similar, indicating that the data of both apply to analogous, if not identical, cultures. We should note, also, that the difference between the two classifications is one of time. One deals with observations upon living natives, the other with what is found
