One of the challenges of studying the past is that time has a maddening way of erasing evidence. Take the origin of life — the ultimate cold case. Had the first organisms been wise enough to fossilize themselves, we would know exactly how life began.

Fortunately, the first organisms did preserve themselves, at least in rough form. That’s because life is itself a kind of time capsule. As life evolves, it keeps a record of the past — a record written in the size distribution of organisms. Bacteria were the first form of life, and today they remain the most numerous organism. More recent inventions add to life’s complexity, but never erase its simple beginning. The result is that the size composition of life, as it exists today, is a reminder of Earth’s deep past.

I think something similar is true of human culture.

In this essay, I explore the idea that the size composition of human institutions, as it exists today, provides a record of cultural evolution. The idea sounds crazy at first. But the more I look at the evidence, the more plausible the idea seems. There are startling similarities between the niche structure of US institutions, and the niche structure of the rest of life on Earth. And that makes me wonder … is cultural evolution replaying (in accelerated form) the same game that life has played for billions of years? It’s too early to say for sure. But the evidence is tantalizing. Let’s have a look.

The past is always smaller

To frame our evolutionary journey, we’ll start at the beginning … the very beginning. The universe was born about 13.7 billion years ago in a Big Bang that created everything we see today. Or more precisely, the Big Bang created the building blocks of everything that exists.

By being born hot and small, the universe did us a favor. It gave history a direction. We humans take for granted the fact that big objects are composed of small objects. Galaxies are made of stars, stars are made of atoms, atoms are made of nuclei, and so on. We (or at least we scientists) also take for granted the fact that this structure evolved from the bottom up, small to large.

Why is the universe built this way?

Physicist Eric Chaisson has spent his career thinking about this question. In his revelatory book Cosmic Evolution, Chaisson recounts the evolution of structure in the universe.1 History has a direction, Chaisson argues, because the universe is expanding. The importance of expansion stems from basic thermodynamics. What drives the growth of structure is the (net) flow of energy. And it’s the universe’s expansion that enabled this flow. (I’ll describe how it works in a moment.)

To convince yourself that energy flows are key for creating structure, try the following experiment:

  1. Fill a pot with water;
  2. Set the pot on the table;
  3. Wait for structure to emerge.

How long would you have to wait before ‘cells’ emerge, as shown in Figure 1? No one knows the answer for sure. But the heat death of the universe would probably come sooner.

Figure 1: When energy flows through a liquid, convection cells emerge.

Now let’s redo the experiment, but this time add a flow of energy:

  1. Fill a pot with water;
  2. Set the pot on a hot stove;
  3. Wait for structure to emerge.

Once the water is on the stove, how long will it take for ‘cells’ to emerge? Probably a few minutes. The reason stems from thermodynamics. When liquids are heated from below, they form convection cells that help dissipate energy. Although convection cells are a rather boring form of structure, the same principle applies to everything in the universe. Energy flow gives rise to complex structure.

Back to cosmic evolution. If the universe is our ‘pot’, where is its ‘stove’? Interestingly, the ‘stove’ is actually the universe’s expansion. The key thing about expansion is that it let the universe cool.2 And that let the fundamental forces work their magic. The result is that matter clumped together, ignited itself into stars, and eventually provided the ‘stove’ of life. Figure 2 shows a stylized picture of this process. (Ed. note. See original piece for this illustration.)

At this point, you might be wondering why I am talking about the universe’s expansion in an essay that is ostensibly about cultural evolution. Well, the point is that if the universe was not expanding, there wouldn’t be any culture to evolve. Moreover, it is because the universe is expanding that history has a direction. The past is always smaller.

Life, from small to big

Like everything else in the universe, life began small. It started out as simple cells, which gradually evolved into the big organisms that exist today. Figure 3 shows a stylized picture of the process. (Ed. note: Illustration in original post.

Interestingly, although life got bigger over time, it never abandoned its previous niches. Today, the first form of life — bacteria — remains the most numerous. In fact, when we look at the size spectrum of life as it exists today, we implicitly peer into the history of evolution.

To that end, Figure 4 shows the size distribution of life. You can see that it clumps neatly into size niches, and that when we look at ever-larger organisms, we repeat life’s evolution. Life began as bacteria, which evolved into protists, which evolved into multicellular invertebrates, which became fish, which became mammals.

Figure 4: The size spectrum of life on Earth. This chart shows how organism abundance varies with mass. Each point represents the average mass and abundance for a species. For sources and methods, see ‘The Evolution of Big’.

In ‘The Evolution of Big’, I reflected on these size transitions, and tried to situate human societies within the rest of life on Earth. As individual organisms, humans are unexceptional. (We’re the black dots in Figure 4.) But when we look at human groups, things get interesting.

Suppose we treat modern firms and governments as ‘superorganisms’. When we do that, we find that these ‘superorganisms’ extend the size spectrum of life by four orders of magnitude. Figure 5 shows the trend.

Figure 5: Human ‘superorganisms’ extend the size spectrum of life. Blue points replot the biomass spectrum from Figure 4. Red points show my estimates for the mass and density of human ‘superorganisms’ — US institutions treated as organisms. [Sources and methods]

Looking at the evidence, it’s clear that the history of evolution is imprinted in the size spectrum of life. And we can thank the Big Bang for that. Because the universe (and everything within it) was born small, life had no choice but to erect itself from the bottom up.

Life’s major transitions

When it comes to the big picture of evolution, what stands out is not the incremental change, but rather, than the epic-making transitions. The reasons for these transitions are complex in practice, but simple in principle. Transitions occur when life runs into design barriers.

Take bacteria as an example. Their simple design works superbly on the microscopic scale. But it would be disastrous if scaled to macroscopic proportions. And that’s why there are no bacteria the size of blue whales.

Although most of life’s major transitions occurred millions (if not billions) of years ago, they remain imprinted on modern life. To see them, we need only peer at life’s size niches. Figure 6 tells the story.

Figure 6: Life’s composition by organism size. From small to big, life’s modern niches repeat evolution’s major transitions. The horizontal shows organism mass. The vertical axis shows the composition of organisms by major taxa. [Sources and methods].

Behold human superorganisms at the top of the scale — the pinnacle of life’s size evolution. How did we get their? The answer is obviously that humans evolved. But more than that, our culture evolved.

Size niches of human institutions

With cultural evolution in mind, let’s zoom in on human ‘superorganisms’. Like the rest of life on Earth, it turns out that human institutions have size niches. Figure 7 shows the pattern for the modern United States.

Figure 7: The size composition of US institutions. [Sources and methods].

With this evidence in mind, here’s a question (that is bound to be controversial): as we move up the size spectrum of US institutions, do we replay the history of cultural evolution? I think the idea is surprisingly plausible.

Small-group origins

At the bottom of the US institution-size spectrum we find private firms. Surely these groups are not humanity’s original form of organization?

No, they are not … just like modern bacteria are not the original form of life. Today’s bacteria have had billions of years to improve their design, so they can do things that early life could not. The same goes for ‘firms’. Today’s private firms are geared towards monetary exchange and organized around private ownership — things that ancient human groups did not do. Still, I think that small firms have much in common with ancient human groups.

The key is that small firms are, well, small. It’s on the small scale that human culture began. And I suspect that if we studied the day-to-day relationships within small firms, they would probably look similar to the relationships found in early human groups.

The origin of government?

Continuing up the size scale, the next institution to appear after ‘private firms’ is ‘local government’, which emerges when groups get close to about 100 members (Figure 8).

Figure 8: Local governments start to appear around Dunbar’s number. The size composition of US institutions, reproduced from Figure 7. [Sources and methods].

This group size is interesting because it’s close to ‘Dunbar’s number’. In the late 1980s, the anthropologist Robin Dunbar discovered a tight relation between the (relative) size of primate brains and the size of their groups. The larger the brain, the larger the group. When Dunbar extrapolated the trend to humans, he predicted a group size of about 150 members. (Incorporating uncertainty widened the prediction to between 100–230 members.)

Dunbar proposed that a group-size of 150 represented our ancestral state. It is the maximum size of group that we can form spontaneously, without formal organization. So it is fascinating that in the modern US, local governments start to appear around this size.

Also interesting is the fact that it is local governments that appear first. Does this tell us about the evolution of the ‘state’? We know that city states were the first form of entrenched government. So it is intriguing that thousands of years later, it is local governments that remain the first to emerge as we move up the spectrum of size.

The origin of capitalism?

Continuing up the size spectrum, next we get ‘public firms’ — companies traded on the stock market. In the modern US, these firms become prominent when groups exceed about 1000 members.

Figure 9: Pubic firms and the origin of capitalism. The size composition of US institutions, reproduced from Figure 7. [Sources and methods].

Here’s another controversial question: does the emergence of public firms tell us about the origin of capitalism?

The answer depends on how we define ‘capitalism’. Marxists like Robert Brenner think capitalism is defined by the spread of wage labor. World-system theorists like Immanuel Wallerstein and Andre Gunder Frank think the spread of international trade is most important. And more recently, Jonathan Nitzan and Shimshon Bichler have focused on the spread of ‘capitalization’ — the ritual of converting property rights into money.

Let’s suppose that Nitzan and Bichler are right, and that capitalization is the defining feature of modern capitalism. It follows that the origins of capitalism are tied to the evolution of the public firm. That’s because public firms take the ritual of capitalization to its most extreme. (We know the capitalized value of public firms down to the second.)

Today’s public corporations have their origins in the ‘joint-stock’ companies of the past — companies that have a surprisingly long history. (Historian Joe Carlen traces them back to 7th century China.) I won’t delve into this history here. But I think it would be fascinating to study the origins of capitalism in terms of the size evolution of joint-stock companies.

The origin of the modern state?

As we reach the size pinnacle of US institutions, we find state governments, followed by the behemoth federal government. It’s not a surprising result, but one that is still interesting.

Figure 10: Are ‘state’ governments always the largest institution? The size composition of US institutions, reproduced from Figure 7. [Sources and methods].

In the social sciences, there is a bitter divide between people who study ‘firms’ (economists) and people who study the ‘state’ (political scientists). Economists look at firms and see ‘free markets’. Political scientists look at the ‘state’ and see the exercise of power. The two approaches seem completely at odds.

I think that studying the size spectrum of institutions can help remove this divide. The key is that the ‘free market’ of economic theory lives at the bottom of the institution-size spectrum among small private firms. As we move to larger institutions, there is less and less ‘free market’ to be had, even if the groups still call themselves ‘firms’.

No one would mistake Walmart’s massive chain of command for a ‘free market’. Instead, Walmart’s hierarchy has more in common with government bureaucracy than it does with the ‘perfect competition’ of economic textbooks. I think this is true as a general rule. As we move to larger institutions, they become more ‘state-like’. The official ‘state’ is simply the biggest brute of them all.

Interestingly, the blurred line between ‘firm’ and ‘state’ is evident in the history of the joint-stock company. When Europe conquered the world (starting in the 15th century), joint-stock companies were a key part of imperial expansion. Companies like the Dutch East India Company were ostensibly ‘firms’. Yet in the territories they occupied, these companies operated more like ‘governments’. For that reason, historian Arthur Weststeijn calls these behemoths ‘company states’.

What I like about this view of the state is that it allows for both continuity and disjuncture. As we move up the spectrum of size, groups become increasingly ‘state-like’. And yet the official ‘state’ has characteristics that are quite different from other groups.

Creeping bigness

Looking at life’s evolution, the biologist Stephen Jay Gould famously saw stasis rather than change. He had a good point.

If there was a universal evolutionary drive towards bigger size and greater complexity, the Earth would look wildly different than it does. The soil would not teem with bacteria, nor would the ocean be filled with phytoplankton. These tiny organisms would have long ago abandoned their niches, either by growing larger or by going extinct. Today, big life would be all that remains.

The fact that we don’t live on a big-organism-only Earth tells us something about evolution. According to Gould, it means there is no universal drive towards complexity. Instead, there is a ‘random walk’:

The vaunted progress of life is really random motion away from simple beginnings, not directed impetus toward inherently advantageous complexity.

In the ‘random-walk’ model, simple beginnings never go away. Instead, small organisms persist as the basis of life, on top of which a few organisms grow larger and more complex. Here’s Gould’s illustration of the creep towards complexity. (Ed. note: See illustration in original post.)

If Gould is correct, then life looks the way it does precisely because there is no universal drive towards complexity. Instead, there is a ‘random walk’ in all directions. Some organisms evolve to be bigger, others to be smaller. The catch, Gould observes, is that in the small direction, there is a ‘left wall of minimal complexity’ beyond which nothing can go. In other words, bacteria are about as small as life can get. (Viruses are smaller, but cannot replicate on their own.) But on the right side, there was no such wall. And so life took a random walk towards complexity.

The result is that life remains pressed against the lower size limit, while at the same time creeping towards bigness. This size creep, however, was not continuous. Instead, it was marked by long periods of relative stasis, punctuated with rare (but monumental) transitions. After 4 billion years of evolution, the outcome looks like Figure 12. Life is organized into different size niches, each of which solves specific design problems. And at the bottom of the size spectrum, life remains pressed against the lower wall.

Figure 12: Size niches of life on Earth. In this ‘violin plot’, the width of each violin indicates organism density at the given size. The violins are normalized so that they all have the same maximum width. [Sources and methods].

Remarkably, a similar pattern emerges among human institutions, as shown in Figure 13. In the modern United States, private firms remain pressed against the lower size limit of 1 person. On top of this minimum social complexity live larger institutions, each occupying a specific size niche. As with organism niches, the existence of institution niches suggests an evolutionary history of what Stephen Jay Gould calls ‘punctuated equilibrium’ — long periods of stasis marked by brief moments of monumental transition. (We’re probably living through a ‘punctuation’ right now.)

Figure 13: Size niches of US institutions. In this ‘violin plot’, the width of each violin indicates institution density at the given size. The violins are normalized so that they all have the same maximum width. [Sources and methods].

What is fascinating is that evolution seems to be repeating itself. In effect, what happened to organisms is now happening to human institutions. But because we are now dealing with cultural evolution, the rate of change is orders of magnitude faster.

And that raises the question: what will the niche structure of human institutions look like in 1000 years? Will it have crept toward even larger scales of organization? Or will our ‘superorganism’ experiment have ended in disaster, marked by a dramatic collapse towards the small scale?

Only time will tell.

This work is licensed under a Creative Commons Attribution 4.0 License. You can use/share it anyway you want, provided you attribute it to me (Blair Fix) and link to Economics from the Top Down.

Ed. Note: Please see Sources and Methods in original post.


  1. Chaisson’s book Cosmic Evolution is epic, but requires some knowledge of physics. (It contains quite a few equations.) For an equation-free telling of the same story, see Chaisson’s later book Epic of Evolution: Seven Ages of the Cosmos.↩︎
  2. What is amazing is that equations derived from studying simple mechanical systems seem to apply to the entire universe. In the 17th and 18th century, physicists discovered that gases obey a simple formula. Take pressure P, multiply it by volume V, and divide by temperature T. The result is always constant:
    \displaystyle \frac{P \cdot V}{T} = k

    This equation is called the ‘ideal gas law’, and it tells us that when a system expands, temperature will decrease. That’s true in your air conditioner. And it’s true for the universe as a whole.↩︎

Further reading

Brenner, R. (1976). Agrarian class structure and economic development in pre-industrial Europe. Past & Present, (70), 30–75.

Carlen, J. (2016). A brief history of entrepreneurship: The pioneers, profiteers, and racketeers who shaped our world. Columbia University Press.

Chaisson, E. (2002). Cosmic evolution: The rise of complexity in nature. Cambridge, Mass.: Harvard University Press.

Chaisson, E. (2005). Epic of evolution: Seven ages of the cosmos. New York: Columbia University Press.

Dunbar, R. I. (1993). Coevolution of neocortical size, group size and language in humans. Behavioral and Brain Sciences16(04), 681–694.

Fix, B. (2019). Energy, hierarchy and the origin of inequality. Plos One14(4), e0215692.

Frank, A., & Gills, B. (1996). The world system: Five hundred years or five thousand? Psychology Press.

Gould, S. J. (1996). Full house: The spread of excellence from Plato to Darwin. Three Rivers Press.

Hatton, I. A., Dobson, A. P., Storch, D., Galbraith, E. D., & Loreau, M. (2019). Linking scaling laws across eukaryotes. Proceedings of the National Academy of Sciences116(43), 21616–21622.

Nitzan, J., & Bichler, S. (2009). Capital as power: A study of order and creorder. New York: Routledge.

Suaste Cherizola, J. (2021). From commodities to assets: Capital as power and the ontology of finance. Review of Capital as Power2(1), 1–29.

Virkar, Y., & Clauset, A. (2014). Power-law distributions in binned empirical data. The Annals of Applied Statistics8(1), 89–119.

Wallerstein, I. (1974). The modern world-system I: Capitalist agriculture and the origins of the European world-economy in the sixteenth century (1st ed.). Academic Press Inc.

Weststeijn, A. (2014). The VOC as a company-state: Debating seventeenth-century Dutch colonial expansion. Itinerario38(1), 13–34.


Teaser photo credit: By NIAID: These high-resolution (300 dpi) images may be downloaded directly from this site., Public Domain,