Hierarchical Diffusion

Have you ever noticed how certain words and trends seem to start out of nowhere? All of a sudden, everyone is repeating a certain meme or wearing a certain brand of clothing. If you were paying attention, it probably wasn't that mysterious: an influencer millions follow on social media popularized the trend. This hierarchical marketing strategy probably started in a corporate boardroom.

If you want people to learn about and buy your product, hierarchical diffusion is the way to go!

Hierarchical Diffusion Definition in Geography

Hierarchical diffusion is one of three principal types of expansion diffusion, along with contagious diffusion and stimulus diffusion.

A (Very) Brief History of Hierarchies

Hierarchical diffusion has existed as long as humans have organized their societies into hierarchies, a process known as stratification.

While "influencers" is a recent term from the age of social media, it describes a process predating states and agricultural civilization. In hunter-gatherer societies, influence diffused from individuals with outsized statuses, such as shamans and other religious figures.

Fig. 1 - A tableau of shamans from Alaska, Siberia, and elsewhere

Here's how it worked. The shaman had an idea such as a vision, and it diffused to older and wiser members of a group (from one to few). These few accepted the vision and spread it to the rest of their group (few to many). In this simple example, the hierarchical diffusion had three tiers (levels).

With the rise of sedentarism, the state, and complex urban civilizations around seven thousand years ago, hierarchies became rigid (fixed), with those who possessed military prowess, religious authority, inheritance (prominent families), wealth, and other factors typically at or near the top (the few). Power became concentrated there, under a single ruler (the one), and societies became organized in classes and castes (tiers comprising the many).

A Pyramid Scheme

At the bottom of the social pyramid were people such as small farmers and laborers, most of the population in most societies until modern times. They possessed the least power.

With the rise of modern democratic systems and representative governments in the 1700s AD, reverse hierarchies began to evolve based on the idea that those at the top, who govern the many and organize society's affairs, only do so with the consent of the governed.

Though in most modern societies, everyone is technically equal in the eyes of the law, hierarchies still exist because power is accumulated via capital (money), so those people and organizations with the most money have far more cultural, economic, and political power and voice than those with less.

Hierarchical Diffusion Model

Using a basic diagram, it is easy to conceptualize how diffusion works in a hierarchy.

Fig. 2 - A basic hierarchy with three tiers. Cultural power and influence can diffuse vertically in either direction: upward ("in reverse," from the many through the few to the one) or downward (from the one through the few to the many)

Reverse Hierarchical Diffusion

A classic model of reverse hierarchical diffusion is the street protest that topples a dictator. During the French Revolution in 1789, a rigid hierarchy controlled by the French monarchy that had lasted for centuries came tumbling down as groups of peasants and others at the bottom of the social and economic pyramid began to organize to overthrow the entire system.

The US's revolution, which preceded France's by a decade, replaced a rather rigid hierarchy with a more limited one. The "Founding Fathers" were a small group of white men who did not attempt a complete tear-down of the old system (infamously, they were not able and most were not willing to abolish slavery), but did establish a system that favored the gradual enfranchising of groups with minimal or no power in the hierarchy: African-Americans, Indigenous people, women, etc. Many of these changes were due to reverse hierarchical diffusion.

Difference between Hierarchical and Reverse Hierarchical Diffusion

The difference between hierarchical and reverse hierarchical diffusion is sometimes unclear because both can happen together. Even more confusingly, those at the top may take credit for what starts at the bottom, or vice versa! Let's see how this works.

Say an agricultural innovation happens in a rigid hierarchy. It's ancient Egypt, and a farmer figures out a more effective way to harness Nile flooding in his village. Local administrators take notice and alert their superiors, who alert their superiors. Eventually, the amazing invention reaches the ears of the Pharaoh. The Pharaoh then mandates that this innovation be incorporated across all of Egypt. Is an example of reverse hierarchical diffusion followed by hierarchical diffusion?

Fig. 3 - The famous monuments of ancient Egypt were attributed to pharaohs such as Khufu and Khafre, but in reality, like the control of annual Nile flooding, were the result of complex processes of hierarchical diffusion that included many innovations made by the "common people" lowest on the hierarchy

Not necessarily! The Pharaoh cannot have it look like a mere peasant was responsible for something this important, so the Pharaoh has his scribes write history a little differently. In the "official" account, Pharaoh had the idea in the first place, perhaps after a chat with the gods.

A similar dynamic is at work in the US. Telling a story by evoking solely the person at the top, whether a CEO, a billionaire, or a president, is common but can hide contributions from all tiers of a hierarchy that made the top level's actions possible.

Examples of Hierarchical Diffusion

You can find hierarchical diffusion in politics and government, economics, and culture. It is in political geography and economic geography, not just cultural geography.

As we said earlier, cultural mentifacts such as ideas, words, statements, symbols, and memes are propagated "downward" or "upward" in a hierarchy. In modern hierarchies, electronic media are the primary means for the diffusion of mentifacts.

Hierarchical Diffusion in Political Geography

Governments hierarchically diffuse laws and decrees. The process of making laws ideally diffuses in a reverse hierarchy (voters form lobbies), but once lawmakers pass them, laws are enforced from the top down.

Emergency situations often rely on hierarchical diffusion. This is because, for efficiency, governments take emergency powers to stop some of the reverse diffusion that occurs in a democratic hierarchy. Orders filter from the top down.

Hierarchical Diffusion in Economic Geography

Despite terms such as "trickle-down economics," money and fiscal policy do not always move hierarchically in a market-based system. There is some hierarchy, though: a few institutions with more (i.e., banks) rely on a single central government-associated group such as the Federal Reserve Board or a central bank, and in turn banks loan to many borrowers. But more relevant to the propagation of mentifacts is the marketing of products.

Commercial marketing is partly a cultural activity because it relies on messages and (usually) the use of images and even videos. Word-of-mouth marketing does happen, which is contagious diffusion, but it is more cost-effective as a corporate marketing strategy to also use hierarchical diffusion.

A hierarchy with various tiers isn't technically necessary, because any person or company today wishing to market a product can reach millions instantaneously (in theory) via the Internet. In reality, though, effective marketing targets different geographic markets and demographics with different ads in a multi-tiered strategy and utilizes intermediaries (intermediate nodes) such as social media influencers to do so.

Hierarchical Diffusion in Cultural Geography

Culture, via mentifacts, is always the medium for diffusion even if what is diffusing involves the government or the economy. But what about artifacts and sociofacts? Where do they come in?

Artifacts are propagated after mentifacts or together with them, often with the help of sociofacts.

Sociofacts themselves also sometimes diffuse hierarchically. This happens when someone high up in the hierarchy has the power to propagate a new type of institution. This can be seen happening in a country that has transitioned from a dictatorship to a democracy (which might have started after reverse hierarchical uprisings, you may recall). New leaders are responsible not only for new laws but also for entire institutions such as democratic government bodies that might not have existed before.

Many cultural mentifacts diffuse hierarchically. The foods you eat, the music you like, and even the architecture of your home may have become popular via a government or corporate promotional campaign. The modern cultural landscape itself is largely a result of the influence of tastemakers over the centuries, rather than a purely vernacular (local and contagiously diffused) phenomenon.