If you've done any reading in folklore, you may have noticed that mythic systems tend to fall into one of two broad categories. Although like most things in life, there is some overlap between them.

One is what I call "state" myths; the myths of the conquerors and the rulers — the powers-that-be. These are usually better organized, more coherent, and formalized. They mainly provide justification for conquest and legitimization for the right-to-rule, and as propaganda are widely and actively promoted within the area being controlled.

Being largely politically motivated, they tend to be rewritten whenever there's a change in the balance of power. Groups that tie their identity to these myths rise to prominence or fall to obsurity with these changes.

Behaviors associated with these myths are usually prescriptive: things that should be done, or proscriptive: things that shouldn't be done.

The other category is what I call "folk" myths; the myths of the conquered and the commons. These are fragmentary, informal, and localized, and tend to be discounted by those promoting "state" myths.

They mainly focus on description of the way things are and how they got that way. They also are concerned with the identity of the local group. Transmission of the myths tends to be implicit; that is within the context folktales and festival events.

Being largely tied to day-to-day survival, change is slow and mostly driven by natural events. Barring outside interference, groups that define their identity with these myths, are stable and slow to change with tradition acting as a brake.

Behaviors associated with these myths are usually descriptive: things that are being done. The myths of minzoku shintô mostly fall within this category.