Similarly Boas' study of the Raven cycle of American Indian mythology indicated that these stories originated in the northern part of British Columbia and traveled southward along the coast. One of the evidences of the direction of this progress is the gradual diminution of complexity in the stories as they traveled into regions farther removed from the point of origin.
All this, in so far as it seeks to determine the point of origin, direction, speed, and character of changes that take place in cultural materials in the process of diffusion, is clearly history and ethnology.
Other questions, however, force themselves inevitably upon the attention of the inquiring student. Why is it that certain cultural materials are more widely and more rapidly diffused than others? Under what conditions does this diffusion take place and why does it take place at all? Finally, what is the ultimate source of customs, beliefs, languages, religious practices, and all the varied technical devices which compose the cultures of different peoples? What are the circumstances and what are the processes by which cultural traits are independently created? Under what conditions do cultural fusions take place and what is the nature of this process?
These are all fundamentally problems of human nature, and as human nature itself is now regarded as a product of social intercourse, they are problems of sociology.
The cultural processes by which languages, myth, and religion have come into existence among primitive peoples have given rise in Germany to a special science. Folk-psychology (Völkerpsychologie) had its origin in an attempt to answer in psychological terms the problems to which a comparative study of cultural materials has given rise.
From two different directions ideas of folk-psychology have found their way into modern science. First of all there was a demand from the different social sciences [Geisteswissenschaften] for a psychological explanation of the phenomena of social life and history, so far as they were products of social [geistiger] interaction. In the second place, psychology itself required, in order to escape the uncertainties and ambiguities of pure introspection, a body of objective materials.
Among the social sciences the need for psychological interpretation first manifested itself in the studies of language and mythology. Both of these had already found outside the circle of the philological studies independent fields of investigation. As soon as they assumed the character of comparative sciences it was inevitable that they should be driven to recognize that in addition to the historical conditions, which everywhere determines the concrete form of these phenomena, there had been certain fundamental psychical forces at work in the development of language and myth.[21]
The aim of folk-psychology has been, on the whole, to explain the genesis and development of certain cultural forms, i.e., language, myth, and religion. The whole matter may, however, be regarded from a quite different point of view. Gabriel Tarde, for example, has sought to explain, not the genesis, but the transmission and diffusion of these same cultural forms. For Tarde, communication (transmission of cultural forms and traits) is the one central and significant fact of social life. "Social" is just what can be transmitted by imitation. Social groups are merely the centers from which new ideas and inventions are transmitted. Imitation is the social process.
There is not a word that you say, which is not the reproduction, now unconscious, but formerly conscious and voluntary, of verbal articulations reaching back to the most distant past, with some special accent due to your immediate surroundings. There is not a religious rite that you fulfil, such as praying, kissing the icon, or making the sign of the cross, which does not reproduce certain traditional gestures and expressions, established through imitation of your ancestors. There is not a military or civil requirement that you obey, nor an act that you perform in your business, which has not been taught you, and which you have not copied from some living model. There is not a stroke of the brush that you make, if you are a painter, nor a verse that you write, if you are a poet, which does not conform to the customs or the prosody of your school, and even your very originality itself is made up of accumulated commonplaces, and aspires to become commonplace in its turn.
Thus, the unvarying characteristic of every social fact whatsoever is that it is imitative. And this characteristic belongs exclusively to social facts.[22]