The issue explored in the concluding sections is the nomads as cultural mediators. Inner Asia, of course, has long been recognized as a zone of cultural transmission, but the nomads' role in such transfer is typically couched in purely political and logistical terms: the nomads create a pax, thus permitting secure travel and trade across the continent. As we have already seen, the nomads' role in East–West exchange is in fact far more intimate and complex than is usually acknowledged. However, to come to grips with this matter, we need first to look more closely at the nature of cross-cultural contact and exchange.

In the early days of European anthropology the study of contact between cultures was cast in terms of diffusion, which was viewed as change by simple addition. New traits in the form of ideas, commodities, or technologies were borrowed from an outside “donor” culture, thereby transforming, in some measure, the “receptor” culture. Moreover, it was fashionable to assume that humans were so unimaginative that innovation was rare and diffusion therefore the main engine of history. In its more strident forms this theory led to fanciful reconstructions of world cultural history based upon transcontinental and intercontinental cultural transfers from a single center of innovation, usually identified as ancient Egypt.

In the course of the first half of the twentieth century there emerged a much more sophisticated and subtle understanding of intercultural relations, a school of thought generally called acculturation studies.