Large social systems, especially those with many members who do not know each other, evolve into hierarchies because the number of connections is reduced.
When the number of connections that hold a group together is reduced, it is less costly to maintain the group and thus such groups are more likely to survive.
Military organizations, companies, religious organizations and schools are usually organized into hierarchical structures. Creative, independent modules can relieve some of the formalism of hierarchy but these modules will still fit into the hierarchical structure somewhere.
Hierarchies are (always?) organized around a purpose—money for corporations, winning for militaries, belief and organizational systems for religions, food for animals and so on.
You can even see the hierarchical principle in plant structures.
A research project on this topic as it applies to artificial intelligence demonstrates that biological networks evolve into hierarchies:
…because hierarchically wired networks have fewer connections. (Research showing why hierarchy exists will aid the development of artificial intelligence)
If we accept this principle behind the development of hierarchies, I would submit that we can also apply it to how language has developed as a hierarchy in and of itself and also as a support system for the social hierarchy within which it is used.
Language and culture are held together by a system of hierarchical categories.
These categories are what we think of as beliefs, values, codes, stories, political systems, who’s who in the group, and so on.
Hierarchical systems based on general categories of that type typically also exist between individuals within any society. Indeed, we can find the same sort of hierarchical system within the individual.
This is an efficient and very reasonable way to maintain a society and a language.
Problems arise in this system, however, when the individual does not know any other way of organizing themself or of communicating with others.
An individual who exists and communicates only within a hierarchical structure will be alienated from the great mass of idiosyncratic perceptions, responses, thoughts, and emotions that exist within them and others. I think that this causes a great deal of psychological suffering and is a major part of what the Buddha meant by delusion.
FIML is designed to fix this problem between individuals.