One of the chief reasons I became an advocate of the Cultural Multilevel Selection (CMLS) theory is that it wonderfully clarifies the relationship between competition and cooperation.
If you wanted a two-sentence summary of Ultrasociety this would be it.
I’ve been applying these principles in my research on the evolution of complex societies (and a lot more is to come, now that the Seshat Databank have come of age and is generating a tremendous volume of empirical results—which you will see in a year or two, as academic publication mill-stones grind sooo slowly).
But I have also felt that the CMLS theory tells us a lot not only about political organizations like the states, but also about economic organizations—firms competing in markets. This goes very much against the grain, especially as far as economists are concerned. Milton Friedman, of course, always argued that economic agents should strictly follow their material interests; there is no place for “extra-rational motives” in business. Most economists today feel the same way, although few are willing to state it as boldly as Friedman did.
Thus, it was very refreshing to receive two years ago an email from Branko Milanovic, an economist whom I greatly admire, in which he was willing to go on record and state this position very forcefully (I published Branko’s letter as a guest blog on Cliodynamica). I also invited two economist friends to comment: Bob Frank and Herb Gintis, as well as writing a response myself. The whole exchange was recently re-published by Evonomics and generated a lot of discussion.
More recently Branko wrote a review of Kate Raworth’s new book Doughnut Economics. A central question in the ensuing debate between him and Kate (see it here) is the same we debated two years ago (see also a good summary on Vulgar Economics). Here’s what Branko wrote about the “human nature under hyper-commercialized global capitalism”:
Here I respectfully decline to be moved by the results of any of the “games” that Kate cites and that are supposed to reveal human nature. These games are indeed games; they are not the way people behave in real life. Games are good in generating publishable papers but they tell us nothing about how the same people would (or do) behave in real life.
Two years ago I wouldn’t know how to respond to Branko on this point, but fortunately recently I finished reading a remarkable book, which provides me all the ammunition I need.
Before discussing it, let’s define the question more explicitly. I agree that most people much of the time, and some people all of the time, are motivated by very “rational” calculations. When I decide which supermarket I am going to go for food, I try to minimize the amount of money I will pay and the amount of time I will spend, while maximizing produce quality and selection. It’s a very straightforward optimization problem.
But capitalism is not just about buying and selling things—people have been doing commerce for millennia before capitalism. Surely the amazing capacity of capitalism to transform knowledge into innovation, and innovation into economic growth is one of the central of its attributes? So let’s talk about such successful innovation hotspots, as the Silicon Valley. What are the motivations driving successful entrepreneurs within such hotspots?
If you want to find out the answers to these questions, read The Rainforest: The Secret to Building the Next Silicon Valley by Victor Hwang and Greg Horowitt. Now, Hwang and Horowitt are not scientists, and their book is not a rigorous scientific study. But they spent decades bringing together venture capitalists and entrepreneurs, both in their native California and all over the globe—“Japan, Taiwan, Scandinavia, and New Zealand, … Mexico, Egypt, Kazakhstan, Colombia, Saudi Arabia, and the Palestinian Territories.” Given their enormous experience, the empirical base, with which they operate in the book, transcends the dismissive academic characterization as “anecdotal.”
A central theme that recurs throughout the book is that successful entrepreneurs, and the successful innovation systems in which they operate, such as the Silicon Valley or Route 128 in Massachusetts, are the antithesis of the rational businessperson postulated by Branko, one who is solely motivated by money. In fact, “Rainforests [their term for successful innovation systems] depend on people not behaving like rational actors.” “For Rainforests to be sustainable, greed must be restrained.” “Predatory venture capitalists might win a few in the short run, but they do not last long in the business and are unable to build lasting firms.”
The evolutionary logic of entrepreneurship, according to Hwang and Horowitt, is precisely the opposite of that posited by Branko. Predatory, super-competitive individuals and firms are eliminated by natural selection, and only cooperative ones survive. They write:
Extra-rational motivations—those that transcend the classical divide between rational and irrational—are not normally considered critical drivers of economic value-creation. … These motivations include the thrill of competition, human altruism, a thirst for adventure, a joy of discovery and creativity, a concern for future generations, and a desire for meaning in one’s life, among many others. Our work over the years has led us to conclude that these types of motivations are not just “nice to have.” They are, in fact, “must have” building blocks of the Rainforest.
Many successful entrepreneurs (think Steve Jobs or Elon Musk) clearly were not motivated solely by money. Naturally, they did not give their billions away, and for some other very successful innovators, perhaps, all they wanted was to become filthy rich. But the point that Branko makes, that capitalism “is a system really built on the best use of our vices, including greed” is clearly wrong.
This is why when governments and corporations try to incentivize innovation by focusing on financial mechanisms, the overall result is failure. By the end of the book, Hwang and Horowitt boil down their own recommendations as to what makes successful “Rainforests” thrive. They are four.
First, diversity, which brings people with very different knowledge and skills together, such as a scientist, a venture capitalist, an engineer, a sales specialist, and an administrator (a CEO).
Second, extra-rational motivations, because self-regarding rational actors are simply unable to cooperate to launch a successful innovation enterprise.
Third, social trust, because successful cooperation is the only way to beat the terrible odds against a successful innovation startup, and cooperation requires trust.
Fourth, a set of social norms that regulate the behavior of various cooperating agents, and willingness both to follow them and to enforce these rules by various sanctions.
In other words, Hwang and Horowitt describe a system that uses precisely the same components to bring about cooperation that have been studied in other settings (a foraging group, a military troop, a religious sect, and a state), and in the abstract, by cultural evolutionists.
The Rainforest, then, provides ample empirical material to reject the theory that economic growth, which is based on innovation, is moved by self-interested rational agents. But—and it was one of the real eye-openers for me—it also explains why this is so. I discuss this in Part II.
I have traveled extensively in southern Africa over the past 25 years—South Africa, Lesotho, Botswana, Zambia, Malawi, and now Namibia. But in all my previous trips I was lucky to see a black rhino only once (in South Africa’s Hluhluwe-iMfolozi Park). The problem, of course, is that by 1995 the world-wide population of the black rhino had collapsed to less than 2,500. From that low point, the species made a tremendous comeback, more than doubling in numbers. And Namibia is probably the best country to reliably see rhinos (both black and white). On a night drive in the Etosha Pan Park a week ago I saw seven rhinos within a span of one hour: first, two black rhinos at a waterhole, then a mother and a baby white rhino at another waterhole, and a family group of three white rhinos by the road we drove on. As it was at night, I don’t have good pictures of these encounters.
Fortunately for a photographer in me, I saw another black rhino in the broad daylight, during a game drive in the Waterberg Plateau Park. As the name indicates, the park is situated on a high plateau (all photos in this post are ©PeterTurchin):
It’s well protected from poachers, so that the population of black rhino there has become a source of rhinos used in re-introductions to areas where rhino were driven to extinction.
Waterberg Park has an ingenious system of blinds, situated next to waterholes, which can be used by humans to spy on wildlife. At one of these blinds we were watching a group of buffalo drinking water and licking salt:
when a fine specimen of black rhino entered stage left:
The first thing he did was mark the territory by spraying urine on the soil and then kicking it back to spread the scent (which is how we knew it was a male):
After that, the rhino’s interactions with the rest of animals were fairly amicable, although everybody (even large buffalo males) gave way when the rhino visited the water hole.
Incidentally, the antelope in the background is the eland, the largest antelope of them all:
Having drunk its fill, the rhino proceeded to the salt lick. On this photo you can see him “licking his chops” (note the tongue):
One of the features of game viewing in Namibia is that the country is very dry, and during the dry season (which is most of the year, anyway) the game congregates around water holes, making it easy to see them. Another notable interaction at a waterhole that we saw some days before in Etosha Pan was an altercation between an elephant and hyenas.
WARNING: a few of the photos below can be considered as quite gruesome! Proceed at your risk.
What happened was that two days before we arrived at the Namutoni Camp in eastern Etosha two lions brought down a giraffe at a waterhole nearby. Alas, by the time we got to the kill, the lions had already departed. But there were plenty of scavengers, vultures and hyenas (and an odd jackal):
Here’s a hyena working on a piece of giraffe, while the head of the poor giraffe looks melancholically on:
The hyenas really trashed the waterhole, dropping rotting pieces of the giraffe in it and defecating. When an elephant showed up for a drink, he was really incensed at such unhygienic habits:
So the hyena decided to drag away what was left of the giraffe’s leg to be enjoyed in privacy, while being chased by the angry elephant:
I can sit for hours watching animals do their thing.
As a boy growing up in Russia I read a bunch of adventure stories about intrepid explorers traveling to far-off places. In one book a band of adventurers voyaged to the Skeleton Coast to search for diamonds. So one might say that it’s been a long time that I dreamed of visiting this remote and dangerous territory. Last week I finally realized the dream.
Over the past week I have been traveling in Namibia with two friends. It’s a spectacular country, justly famous for its landscapes and wildlife.
Our trek up the Skeleton Coast started at sunrise in the quaint town of Swakopmund (all photographs in this blog ©PeterTurchin):
Swakopmund in the early morning
Very quickly all signs of civilization are left behind, and all that one sees is a cold (water temperature is 15°C) and turbulent sea on the left hand side, and a desert on the right side. The road is basically sand cemented by salt:
The road quality actually was quite good. According to reports, it becomes slick and treacherous after a rain, but it hardly ever rains on the Skeleton Coast.
Sand and salt are everywhere; in fact, there are a number of salt-production businesses along the road:
The Skeleton Coast got its name because it is an incredibly dangerous area for navigation. It is literally littered with shipwrecks, from recent ones:
A recent shipwreck
To older ones, which provide excellent nesting grounds for sea birds:
An older wreck
And then to ancient wrecks, that have sunk into the sand:
An ancient wreck
In addition to these “skeletons” of ships, the sand is littered with actual skeletons:
The Skeleton Coast, true to its name
The road ends at an isolated outpost of Terrace Bay:
which doesn’t have a permanent population (people come to work there for three weeks, and then take a week off with their families back home).
The Skeleton Coast is not quite as devoid of life as it looks. Driving out of Terrace Bay the next morning we saw a couple of jackals:
All in all, traveling in this remote and desolate land was a wonderful adventure. Unlike the heroes of my childhood books, I didn’t dig for diamonds in the sand. But if you want to do it, apparently you can:
In the first part of my critique of The Dictator’s Handbook: Why Bad Behavior Is Almost Always Good Politics by Bruce Bueno de Mesquita and Alastair Smith (BDM&S), I slammed the theoretical foundations of their argument. The book also has a lot of empirical content, and in Part II I want to talk about that.
The basic approach taken in the book is anecdotal. It’s not a substitute for rigorous analysis because of the ever-present danger of “cherry-picking”—selecting only the anecdotes that support one’s pet theory, while studiously ignoring any counter-examples (see also Technical Note at the end). But a series of well chosen and well presented illustrations of the theoretical ideas in the book from history, politics, and business could make for an enjoyable reading.
Unfortunately, BdM&S selection of examples exhibits an extreme form of cherry-picking, in fact even going beyond that, when they make out examples supporting their theory “from whole cloth.” For example, did you know what was the cause of the Russian Revolution? It turns out that Czar Nicholas II “foolishly cut the income from one of his major sources of revenue, the vodka tax, at the same time that he fought World War I. … With vodka banned, his revenue diminished sharply. .. Soon Nicholas was no longer able to buy loyalty. As a result, his army refused to stop strikers and protesters.” This is a remarkable story; unfortunately it has nothing to do with the real causes of the Russian Revolution (if you are interested in details, see Chapter 10 of our Secular Cycles).
Another new historical fact that I gleaned from The Dictator’s Handbook was that “Kerensky’s revolutionaries were able to storm the Winter Palace in February 1917.” Of course, it was not “Kerensky’s revolutionaries” but Lenin’s Bolsheviks, and the storm of the Winter Palace was not in February, but in October (old style). If the authors know history so poorly, why didn’t they employ a fact-checker?
These are just two examples out of many more. But more important is the extreme form of cherry picking that BdM&S practice in The Dictator’s Handbook. They only give examples of leaders behaving corruptly (by the way, this is the same criticism that Frederick the Great of Prussia leveled against Machiavelli in Anti-Machiavel).
Frederick the Great of Prussia as Crown Prince (1739), about the same time when he wrote Anti-Machiavel. Source
The very first example with which the book starts deals with one Robert Rizzo, who was city manager of Bell, California. There is no question that Bell was an extremely corrupt individual. In fact, he was the highest paid city manager in the entire US! I think it wouldn’t be unwarranted to conclude that Rizzo was in the top 1 percent, or even top 0.1 percent of the most corrupt American city managers. But what about the rest of them?
Remember that the main postulate of the BdM&S theory is that all politicians (as well as all business leaders; in fact all people) are only “motivated to do what is good for them, not what is good for others.” To illustrate this general idea with an individual selected from the top 1 percent of the corruption distribution, and not to balance it with a discussion of how typical this behavior is, is intellectually dishonest.
Now, I am not a starry eyed idealist. I know full well that there is plenty of corruption and self-dealing in our Republic. There are lots of egotistical people. It’s even quite possible that there is a selection process that ensures that the fraction of egomaniacs and narcissists among the political and business leaders increases as one goes up the hierarchy (although I’d like to see some data on that). Nevertheless, not all leaders are like that.
As an example, let’s consider such obvious example of prosocial behavior as volunteering for the army when your country is at war. Of course, George W. Bush and Bill Clinton would be fine examples for the BdM&S theory. But think about the previous generation, which Robert Putnam called the Long Civic Generation. Jack Kennedy fought in World War II, and his older brother, Joseph Jr, was killed in action in 1944.
George W.’s father, George H.W. Bush, was a naval aviator whose plane was shot down by the Japanese, also in 1944.
Shipmates of the submarine USS Finback rescue Bush Source
I return to my main critical point: people are different–some selfish others prosocial; and so are politicians. It is not surprising that The Dictator’s Handbook is so popular—our current generation of politicians may easily be the most miserable one in American history (although Gilded Age politicians could have been even more corrupt). What we need is a theory that would help us understand why there is variation between leaders, and why there is change with time: some generations of leaders behave more prosocially, others are more corrupt. Due to its theoretical and empirical flaws, BdM&S’s book does not advance us towards such an understanding.
Technical Note: Bueno de Mesquita and colleagues have also published a 2003 volume, The Logic of Political Survival. That book, among other things, presents a statistical analysis of predictions from the selectorate theory with Polity IV data. Unfortunately, their analysis suffers from fatal flaws, in particular, because they used a bizarre residualization procedure. In an article published in American Political Science Review, Kevin Clarke and Randall Stone show that this procedure leads to omitted variable bias. When the data are reanalyzed properly, as Clarke and Stone did, most of their important findings don’t survive.
One of my long-term interests is in the dynamics of leader-followers systems. Large-scale societies and other large groupings of people (including corporations) cannot be purely egalitarian. As I’ve written in another post, humans are not ants.
We must have leaders to organize large-scale cooperation. Inevitably, there will be elites (in the neutral sociological sense: simply a small proportion of the population who concentrates social power in their hands) and commoners (the rest of the population). The big question is how do (some) human organizations avoid, or mitigate (to a greater or lesser degree) the iron law of oligarchy – one of the most fundamental sociological laws (put simply, power corrupts).
Thus I looked to reading The Dictator’s Handbook: Why Bad Behavior Is Almost Always Good Politics by Bruce Bueno de Mesquita and Alastair Smith with great anticipation. I had an inkling that I would disagree on much with the authors, but I was looking forward not to agree, but to learn.
I was mistaken. The book fails, and fails badly, on both theoretical and empirical grounds. It’s so bad, I almost decided not to review it. However, it has been enormously successful. It sold a lot of copies, and garnered more than 200 reviews on the Amazon, most of them glowingly positive (average rating 4.6 out of 5). It also inspired a very popular info-video by CGP Grey (over 6 million views).
Thus, I think it becomes my public duty to explain why the book is bad.
One of the few points in the book, with which I agree, is that our job as social scientists is to study how the world really works, not how we wish it worked, or as BdM&S say in the beginning of the book, “the world can only be improved if first we understand how it works and why.”
In the last chapter, the authors say, “After the past nine chapters of our cynical—but we fear accurate—portrayal of politics…” Cynical, yes. Accurate? Far from it.
The theory proposed by BdM&S is a very simple, even naïve, version of the rational-choice model so favored by economists and political scientists in the twentieth century. As the authors say early on in the book, “politics, like all of life, is about individuals, each motivated to do what is good for them, not what is good for others.”
It’s as though the book was written not in 2011, but thirty years ago, before the massive tsunami of evidence showing that this is not true at all.
People are different. Some (20-30% in most large-scale societies) are indeed pure rational actors who only maximize their personal utility expressed in purely materialistic terms. But the majority of population is motivated by additional considerations: desire to do good to others or for the society, loyalty, friendship, honor, sacred values, and many more.
The theory propounded by BdM&S, then, is pure Machiavelli, which they acknowledge by quoting him approvingly. Anyone seeking to become a ruler must give followers “castles and possessions, as well as money and subjects; so that surrounded by these he may be able to maintain his power, and that by his support they may satisfy their ambitions.”
I have debunked this theory at length in War and Peace and War, so I won’t do it here. What is startling is to see this bankrupt theory pushed so vigorously by seemingly competent academics. How could you possibly ignore I don’t know how many thousands of articles in experimental economics that have swept away the naïve, stripped-down version of the rational-choice theory?
You probably think I have presented a caricature of BdM&S’s theory. Not at all! Check the book, or watch CGP Grey’s info-video, which is a very accurate statement of what the book says. Here’s another direct quote: “Paying supporters, not good governance or representing the general will, is the essence of ruling.”
Just about the only elaboration of Machiavelli is BdM&S’s division of followers (a population of a country, or people working for an organization) into essentials, influentials, and interchangeables. If you are interested, read about it in this Wikipedia article—I don’t see the point of discussing it as the overall theory doesn’t make sense to me, because of its bankrupt model of human nature.
Now, I would be the first one to admit that there are a lot of dictators, democratic politicians, CEOs of big corporations, and even leaders of ostensibly charitable organizations who are reasonably well described by the Machiavelli model. But not all leaders are like that. We know empirically that leaders are a mixed lot. Some, like Idi Amin, are really close to the Machiavelli end, while a few are closer to—let’s say—the Gandhi/Mandela end. And most are in between. Why do we see such heterogeneity is a very interesting question, and I will talk about it in Part II.
The last installment in this series (first one here) adopts a more critical stance towards the article by McConnell et al., Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity. As I said in the second post, the only quantitative part of this study was coming up with the lead pollution curve, while all the comparisons between the lead curve and historical events in Rome and elsewhere in the Western Mediterranean were qualitative (with silver content of the Roman denarius the only exception). Here’s the relevant figure:
Figure 3 of McConnell et al. 2018
The problem with an “eyeball” comparison between a quantitative curve and a set of qualitative events is the danger of confirmation bias. Or put simply, cherry-picking of data. It’s way too easy to find an explanation for any uptick and down-tick in the curve when one has a large list of events to choose from. McConnell et al. appear to be guilty of this.
One of the major messages of the article is that wars in the Western Mediterranean, and especially those affecting the Iberian Peninsula, have a depressing effect on silver production (which lead emissions proxy). But the authors also use the opposite effect to explain one of the upticks:
Longer-term declines possibly were linked to disincentives to investment in war-torn regions. For example, lead emissions dropped notably at the outbreak of the first Punic War (264–241 BCE) but rose in the later years as Carthage increased its minting of silver coin to pay mercenaries.
What we need is an objective quantitative method to test the hypothesis of a negative correlation between silver production and warfare. Fortunately, there is such a proxy.
I have literally tons of data on the incidence of coin hoards. It turns out that the overwhelming majority of the hoards we find in modern times are “emergency hoards.” These are buried stores of wealth that people hide during times of danger. And then if something terrible happened to them–they are killed, or enslaved, or driven into exile–the hoards are not recovered by the original owners. Thus, the fluctuations in the frequency of coin hoards per decade provide us with a very useful proxy for the intensity of warfare.
Some years ago Walter Scheidel and I published an article (also in PNAS) which capitalized on this relationship to resolve a long-standing debate in Roman demography. Here I plot the data from that article on coin hoard frequency and and index of war intensity in Italy, derived from textual sources:
The three periods of intense warfare that are prominent in this figure are the Second Punic War and the two rounds of civil wars during the crisis of the Roman Republic (for details, see Chapter 6 of Secular Cycles). So, what happens when we compare the hoard index of war intensity with the lead emissions index? Here’s what:
A correlation coefficient between these two curves, equaling a measly -0.09, confirms that there is no apparent relationship here.
Could it be because the hoards come from Italy, while the hypothesis is that it is warfare in Spain that should depress silver production? We are fortunate to have an Inventory of Greek Coin Hoards that covers all of Mediterranean, and beyond, published by Margaret Thompson and colleagues in 1973. Focusing on the Western Mediterranean, we see the following pattern:
These curves decline shortly after 200 BCE, because the Roman denarius becomes the main means of exchange in the Western Mediterranean (note that Italian Hoards above are largely based on the silver denarius, with a few bronze coin hoards early in the sequence).
Let’s compare the total hoards in West Mediterranean and just hoards in Spain to the lead emissions curve:
The correlation coefficients between the lead curve and either of the hoard curves is actually slightly positive. Thus, I conclude that the hypothesis of McConnell and co-authors, that warfare corresponds to downturns in lead emissions, is not supported.
While I am certainly very grateful to the team of authors of Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity, it is curious that the only quantitative part of their study was coming up with the lead pollution curve. All the comparisons between the lead curve and historical events in Rome and elsewhere in the Western Mediterranean were entirely qualitative. Yet the greatest strength of employing quantitative proxies results when we examine different proxies against each other.
In this second installment of the series (first installment here) I will compare the lead curve to a quantitative measure of building activity in Rome. I will focus on religious buildings (pagan temples and Christian churches), because they typically represent a substantial investment of resources and because they can be often accurately dated. I have used this building index in several case studies described in Secular Cycles. For this post, the list of temples was taken from Richardson, L. 1992. A new topographical dictionary of ancient Rome. Johns Hopkins University Press, Baltimore; and churches are from Ward-Perkins, B. 1984. From Classical Antiquity to the Middle Ages: Urban public building in northern and central Italy, AD 300-850. Oxford University Press, Oxford.
Here I plot these data in two ways:
The tan vertical bars tell us how many temples (or churches) were built in Rome in each decade. The thick brown curve smooths over short-term fluctuations, helping us to visualize longer (secular) dynamics. As we see, the curve generally traces out the four secular cycles in Roman history. One partial exception is the building activity gap in the middle of the first century, which divides the Principate cycle into two phases. One possible explanation of this interruption is that there was a short-lived outbreak of internal violence during the first century (the deposition of Emperor Nero followed by the Year of the Four Emperors).
Now let’s plot the building curve against the lead pollution curve:
What we see is that there is a lot of difference in detail. But there are also shared features. The secular cycles in both curves tend to have peaks and troughs at roughly similar times (except for the “double-headed” Principate cycle in the building data). Additionally, the overall heights of each secular peak are similar in the two curves. The overall correlation coefficient is a respectable 0.62. This is not a bad result, considering that the two curves were derived using completely different methodologies, and that they reflect very different socio-economic processes. On top of that, the first cycle in the pollution curve is not even due to Rome, since the mines during the early period were operated by the Carthaginians.
When I started 20 years ago on the research direction that eventually became Cliodynamics, I thought that getting data to test theories about historical dynamics would be tough. Within a couple of years I realized that actually it’s not true. There is an enormous amount of quantitative data about all kinds of aspects of past societies. It’s true that we often don’t have direct measurements of things we want to know about the past. But if one is willing to keep one’s eyes (and mind) open, one constantly encounters quite good data that can serve as a useful “proxy” for a variable of interest.
This week an interdisciplinary team of climatologists and archaeologists published an article, Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity. The main source of lead particles, deposited on Greenland ice during Antiquity, was a result of smelting silver in Iberian silver mines. The amount of lead deposited in Greenland can be resolved down to the year. As a result, Greenland ice contains an excellent quantitative proxy for the intensity of silver production in Western Mediterranean, which in turn traces economic booms and busts in this part of the world.
I downloaded the raw data, smoothed it using kernel regression with bandwidth = 50 years (if anybody cares for such technical details), and here is the trajectory (concentration of lead in Greenland ice) during the period when Rome was one of, or the dominant power in Western Mediterranean:
What we see here is yet another illustration of one of the most pervasive macrohistorical generalizations: all complex societies go through multi-centennial (“secular”) cycles (see our book Secular Cycles). Ancient Rome went through four such cycles of alternating integrative (“good”) periods (indicated with green-colored labels in the figure) and disintegrative (“bad”) phases (indicated with red-colored labels).
Actually, the first cycle probably has more to do with Carthage, which owned Spanish silver mines at the time. In the last cycle (the Dominate), the center of gravity of the Roman Empire shifted east, and that’s probably why the fourth century’s peak is quite modest.
Note that I did the periodization of Roman history into secular cycles before the Greenland ice data were available. It was based on a series of quantitative proxies that are entirely separate from the lead pollution data (and there are many such proxies — in the next post I’ll look into how they correlate with this one). In other words, these new data provide an independent test of the secular cycles theory.
You can read about these Roman cycles in the already mentioned Secular Cycles, and in my popular book War and Peace and War (in particular, Chapter 6, Born to Be Wolves, on the early history of Rome. For the last cycle (the Dominate) there is an article in Cliodynamics by David Baker.
You can also trace the evolution of the Roman polity from the Roman Kingdom (716–509 BCE) to the collapse of the Western Roman Empire (395–476) on the just published beta-version of the Seshat visual data site.
Yesterday the top science journal Nature published a bomb-shell article, but my feeling is that biologists haven’t yet realized the explosive nature of the report. I’ll explain, but first we need to make a lengthy excurse into the history of the group selection idea.
Whether group selection is an important evolutionary force, or not, is a highly controversial question in evolutionary science. A substantial proportion of evolutionary scientists still think that it is not. The stakes are high because I and many other proponents of Cultural Evolution think that group selection (or, as we prefer to call it, multilevel selection—selection acting simultaneously on individuals and groups) provides the key to our understanding of the evolution of human ultrasociality—the capacity of human beings to cohere and cooperate in huge societies (millions and more of people).
Actually, the best theory that enables us to understand ultrasociality is “Cultural Multilevel Selection” (see my book Ultrasociety about how human societies evolved from small bands of hunter-gatherers of 10,000 years ago to the huge megasocieties of today by the process of multilevel selection acting on cultural traits). I tend to agree, to a certain degree, with the critics that genetic group selection is not a commonly encountered evolutionary mechanism in the field, although in the past it was clearly hugely influential. Because how would, otherwise, we get multicellular organisms? And genetic multilevel selection provides the best explanation, in my opinion, of other “major evolutionary transitions”, which include, in addition to multicellular organisms, such epochal events in biological evolution as the rise of the eukaryotic cell and social insect colonies.
The first proponent of genetic group selection was Charles Darwin himself, who wrote about it in his second major book, The Descent of Man and Selection in Relation to Sex, which was published 12 years after On the Origin of Species. Darwin’s ideas on group selection remained very influential for about a century. One of his well-known followers, the English biologist V. C. Wynn-Edwards, became an advocate of the idea that individual behaviors can evolve not just because they help individuals, but for the good of the species as a whole. In other words, Wynn-Edwards and other adherents of what later became known as “naïve group selectionism” thought that evolution could operate at the level of really large groups—whole species.
I attach the label “naïve” to these views because arguments of Wynn-Edward and others relied on simply pointing out the importance of a trait at the level of a group (or a species) without considering carefully how such traits affected individuals. Incidentally, this is why I prefer “multilevel”—because our current theories explain much better the evolution of behaviors that have opposite effects at different levels (e.g., favor the group but at the expense of individual fitness). It’s not a trivial question, and it requires non-trivial math to figure out when either the group-level or individual level force dominates.
In any case, by the 1970s the tide turned against group selection. The key thinker in this reversal was George C. Williams, and his ideas were popularized by Richard Dawkins in his wildly popular book The Selfish Gene. When I studied biology in graduate school in the early 1980s, nobody believed in group selection, apart from a few “heretics” like my good colleague and friend David Sloan Wilson.
In the last decade or so the tide started turning back. In particular, the hugely influential social biologist Edward O. Wilson (no relation to David) “flipped” from a critic to an adherent of group selection. But many, if not most, continue to reject it (for example, the geneticist Jerry Coyne or the evolutionary psychologist Steven Pinker).
Getting back to Darwin, it is not a coincidence that his second major book, in which he wrote about group selection, has the subtitle Selection in Relation to Sex. Here’s a fun example illustrating this connection, which I have recently used in a lecture in my cultural evolution class last week.
Many of my readers know that there was a species of deer in which males grew astoundingly huge antlers—the Irish Elk. It roamed Eurasia from Ireland to China during the Pleistocene, and went extinct around 8,000 years ago. Why did Irish Elk males sport such spectacular antlers?
The reason, as Darwin explained, is the sexual selection. Every fall male deer (including elk and moose) participate in jousts, with winners getting to mate with females. The larger is the weaponry that you bring to the contest, the better are your chances of winning it, which means mating and passing your genes to the next generation. So natural selection favors males with larger antlers (as they say, “size matters”).
Note “larger”, not huge. What’s important is not an absolute size, but a relative advantage. In the land of small-antlered, the medium-antlered elk is king. But then, in a few generations, everybody has medium-sized antlers, and so to get ahead of the crowd you need large ones. And so on. As the arms race continues, eventually only those elk with gigantic racks have any chance of reproducing. Growing huge antlers is energetically expensive, and a huge risk—whether getting tangled in the branches, or not being able to escape predators due to their heavy weight.
If only elk males could get together and agree to put a limit on the size of their antlers… Everybody would be much better off. Instead, each individual strives for advantage, resulting in a collectively suboptimal outcome. One could say that the Irish Elk went extinct as they literally collapsed under the weight of their antlers.
We don’t really know why the Irish Elk went extinct. Perhaps the reason was the run-away competition between males, resulting in unsustainably gigantic antlers. Or there could be another reason. And here’s why the Nature article, to which I referred in the beginning, is so interesting: High male sexual investment as a driver of extinction in fossil ostracods by Maria João Fernandes Martins and co-authors.
Ostracods are small crustaceans, shrimp-like creatures that protect themselves with bivalve carapaces (shells). These shells are well preserved as fossils, and so we know quite a lot about their evolution.
Fernandes Martins and co-authors analyzed the paleontological data on 93 species that lived in the area that is now Mississippi state between 84 and 66 million years ago. They assessed the strength of competition between males by how much males invested in reproduction, which you can tell by the shape of the shell (e.g., how long it is). Basically what they did was similar to estimating the strength of between-male competition in deer by looking at how large their antlers are. Then they did a statistical analysis on how the strength of sexual competition affected the probability of extinction of the species.
They found that the probability of extinction of the species in which males competed most intensely was ten times higher than in the species in which males did not compete very hard. This is a huge difference, and it lends credence to the idea that the Irish Elk went extinct because of intense between-male competition necessitating high investment by males into growing big antlers.
The implications of the study by Fernandes Martins and co-authors, thus, go far beyond an obscure group of shrimp-like organisms. What we have here is a clear example of multi-level selection. The individual level selection forces each male to invest into sexual competition as much as possible. But at the species level, those species in which between-male competition goes too far, has an order of magnitude higher chance of going extinct. As a result, most species find themselves at an intermediate level of male sexual investment.
It’s interesting that the authors of the Nature article do not even mention multi-level selection, nor do they talk about the broad implications of their study, as I have done in this blog. They are either not aware of them, which seems unlikely, or they simply didn’t want to enter the highly contentious debate about group selection. Equally interesting, Nature apparently did not deem this study to be important enough to devote a News-and-Views article to it. But I think that the implications of the study are explosive. If Wynne-Edwards were alive, he would feel vindicated.
Follow Peter Turchin on an epic journey through time. From stone-age assassins to the orbiting cathedrals of the space age, from bloodthirsty god-kings to India’s first vegetarian emperor, discover the secret history of our species—and the evolutionary logic that governed it all.
200 years ago Alexis de Tocqueville wrote about the exceptional ability of Americans to cooperate in solving problems that required concerted collective action. This capacity for cooperation apparently lasted into the post-World War II era, but numerous indicators suggest that during the last 3-4 decades it has been unraveling.
Pants are the standard item of clothing for people, especially men belonging to the Western civilization. Why not a kilt, a robe, a tunic, a sarong, or a toga?