In a small subset discipline that is often part of - or is at least akin to - anthropology, we can look to folklore for an example. The case of Vladímir Propp demonstrates how Soviet-driven ideology affected theory.

Internationally, scholars looked to folklore (and specifically the folktale) as a legacy from a distant time, seen through a romantic lens often affected by nationalism. From this point of view, storytellers were mere vessels who transmitted folktales from one generation to the next; the better the storyteller the fewer changes to this treasured legacy of a forgotten time. These early folklorists also tended to imagine that "forgotten time" to have consisted of court bards who, in Homeresque fashion, told tales to entertain royalty, aristocratic artists serving the upper levels of society.

Propp published his Morfológija skázki (Morphology of the Folktale) suggesting that the concept of the folktale type was an illusion, an approach that was particularly well-suited for the Soviet Union. As I describe in my Introduction to Folklore:

For Propp and his structuralism, there were no traditional types passing through time with variants manifesting in diverse places. He suggested that a basic format, a set of rules, governed the telling of all folktales. A storyteller would simply follow the rules, picking from a vast menu of motifs. Because there were rules and a set number of motifs, the same stories would eventually reappear, but they were not necessarily linked historically. For Propp, what appeared to be a system organized as types was an illusion. ..., every storyteller had the potential for creativity. A storyteller might repeat a tale previously told, but the narrator could just as easily invent a new story, drawing on motifs and employing the accepted structure of the folktale genre. This interpretation was appropriate for egalitarian ideals of Soviet society, but this is not to dismiss the conclusion simply because it fit in with a political doctrine.

Propp remained untranslated into English until after WWII, at which time, many were looking for a fresh way to consider folklore. While traditionalists eventually elevated each generation's storyteller to an artist in ever sense of the word, the idea of a sustained legacy persisted. Because the Nazis embraced the idea of a "pure" inheritance from an ancient - and necessarily Aryan - time, the older approach was seen as fouled. Propp provided a refreshing means to consider oral narratives.

Again, from my Introduction:

In 1958, Svatava Pirkowa-Jakobson and Lawrence Scott edited and translated Propp’s essay into English, striking a chord that fit the time. Internationally, folklore was ready for a change because of positivism, because of the fascists, and because the tired question of origins was not yielding adequate results in the eyes of many. North America was especially ripe for conversion. Lacking much by way of ancient traditions (aside from those of Native Americans), American folklorists were interested in the dynamic process of creativity. In addition, the combined effect of European fascism and liberal academics drew many American folklorists to an approach that seemed based on the egalitarianism of Karl Marx. Propp was immediately fashionable in many circles for political and philosophical reasons.

Fashionable is one thing; accurate is another. Ultimately, we must ask whether Propp’s approach fits the evidence. One major criticism of Propp’s concept of independent invention is that for years folklorists have asked storytellers for original folktales. When offered large amounts of money for newly-created stories, even the most gifted narrators have had to refuse the invitation, stating invariably that folktales are traditional things to be repeated, but they cannot be invented. It appears, in fact, that the invention of a folktale is extremely rare rather than an on-going process.

Some societies, however, may treat the material in a more flexible, inventive way. Alan Dundes (1934-2005) in his path-finding Morphology of North American Indian Folktales (1964) found that details of various stories frequently changed from one telling to the next, even when told by the same narrator. There is less evidence of this sort of flexibility with European material, but even there, the option of changing folktales cannot be dismissed as non-existent. Cornish droll tellers, the professional storytellers of Cornwall, took pride in altering stories to suit the location and audience, changing stories in a way that might have seemed inappropriate in a place like Ireland, for example. At the same time, it is important to note that Dundes acknowledged that in some cultures – notably those of the Southwest – the faithful transmission of stories was more common than elsewhere among American Indians.

Propp’s analysis of the constant invention of the folktale may not always fit the facts, but that does not negate the validity in the concept. It is reasonable to conclude that there is an underlying structure in oral narrative, and it is worthwhile to understand this structure as thoroughly as possible. Whether the structure can operate independently of a tale type, providing the outline necessary to create similar stories repeatedly over time, is the question. Even if the answer is generally no, the underlying structure may still exist and have significance. In addition, some cultures that place less value on faithfully repeating stories as they are told may be hotbeds of creativity, guided by the rules of oral tradition, continually reinventing tales without any historical connection.

We must, consequently look at Propp's work as ideologically-suited to the Soviet Union, and then it became ideologically-suited to many after WWII. It happens that Propp developed a valuable way to consider oral narrative. I find his work useful, but I don't find it convincing enough to discard other concepts.