There are two terms that are useful here - but a warning: these are the part of the language of specialists that one does not normally encounter in plane conversation. In other words, these can be regarded as jargon, although they have seeped into the English language in a way that them may be shedding their "jargon cloaks." And another warning: these apparently originated in anthropology, so it is not part of the native language of historians, although, againt, the terms have been gaining ground in our shared vocabulary.

The first term is "ethnocentrisms." The word, apparently coined by the Polish sociologist, Ludwig Gumplowicz (1838-1909), describes a prevalent inclination to judge other people based on one's own cultural framework. Ethnographers understand that they must work against a natural tendency to view other cultures as simply doing things in a wrong way.

Our culture embeds such a powerful standard of conduct and a way of viewing the world/thinking about everything that when we encounter people who do it differently, a first reaction is that they are simply backward, stupid or ill-bred. This was a common consequence of European colonization of the lands of other people. Ethnographers worked (and still work) against this perception. Let's keep in mind, however, that ethnocentrisms also manifests in a modern setting when people from some cultures judge what they perceive as the West's decadent sexuality and culture in general. They are looking at Europe and America as ill-bred and failing to observe a natural, standard of what should be a universal standard of acceptable conduct. This, too, is ethnocentrism.

The term ethnocentrism apparently other "centrisms" including anthropocentric (seeing humanity as the center of the universe and the pinnacle of all things including the creation of the world) and importantly here, temporocentrism. This term was coined by the American social scientist, William Graham Sumner (1840-1910).

Like ethnocentrism, temporocentrism involves the prejudicial view of "them." In this case, the frame of reference is not about contemporary cultures; rather, it is about how we view people of the past. Again, there is an inclination to see "them" as "primitives" that have yet to attain our natural order of things, including our sophisticated technologies, but also our superior intellect and world view.

I'm not keen on jargon, and temporocentrism (more than ethnocentrism, which has been around a bit longer), feels like jargon. Nevertheless, it is a useful term and encapsulates a valuable concept, namely, that "our" judgment of "them" whether in another land or another time reveals more about our prejudices than "their" difficiencies.

When writing folklore or history, I allow myself one or two examples of jargon per book or article, BUT ONLY if I clearly define the terms and remind the reader of those definitions later on if necessary. In general, I try to avoid jargon because it is off putting, and frankly jargon is a way for academics to define "us" as superior to "them" (i.e., the uneducated). Jargon can be viewed as an expression of ethnocentrism - an effort to keep "our" superior discussions to ourselves.

Jargon can be useful, however, because a single term can encapsulate a concept that may need to be referred to repeatedly in an essay. In this case, using a gaggle of words to express a concept is a burden and using the term that is jargon is a shortcut. That said, I try to avoid it because I believe the work of academics should be shared as broadly as possible.

edit: under various "centrism" I should have noted egocentric, because, after all, it is all about me!