Why Think About Rome? One Reason: The Fall Of Rome Coincided With A Fall In IQ—Like The Modern West
Print Friendly and PDF

The hashtag #roman empire has reportedly been viewed over a billion times on TikTok, with most videos women asking men the question: How often do you think about the Roman Empire? The surprising answer: a lot. Feminist historian Mary Beard, of course, says it’s because of male chauvinism [How often do you think about the Roman Empire? Expert has thoughts on the new TikTok trend, SkyNews, September 27, 2023]. Well, here’s one reason to think about it: I believe the rise and fall of Rome coincided with the rise and fall of Roman intelligence. Rome fell because its people were becoming less intelligent. And the same thing is happening today.

Many theories attempt to explain the Roman Empire’s collapse. It was overstretched, meaning it could no longer efficiently transport the necessary raw materials. Or it came up against problems that its elite could not solve, leading to the populace losing faith in these elites. The problem with these explanations is that they invite obvious questions. Why did Rome gradually become less efficient? Why were its elites decreasingly able to solve the problems of running a large empire?

The essence of intelligence is “solving problems.” Group-level intelligence is associated with all of the markers of civilization: wealth, numeracy, education, democracy, social trust, obedience to the law and just authority, and, importantly, good health and public hygiene achieved with plumbing and sanitation. (This is explored in the book Intelligence: A Unifying Construct for the Social Sciences, by the late Richard Lynn and Tatu Vanhanen.)

We would then expect civilization to weaken selection for intelligence because it reduces environmental harshness and leads to improved living conditions: again, good public health and hygiene because of widely available food, clean water, and medical care, etc., which decreases the relationship between wealth (socioeconomic status is a robust correlate of intelligence) and how many surviving children one has, with such a relationship existing in the earlier stages of civilization. (I discussed this in my book At Our Wits’ End, with my co-author Michael Woodley of Menie.)

In our new study published last month in OpenPsych, Italian anthropologist Davide Piffer, Danish independent researcher Emil Kirkegaard, and I have attempted to prove the hypothesis. We found compelling evidence that the Roman Empire not only collapsed but also rose due to changes in intelligence [Intelligence Trends in Ancient Rome: The Rise and Fall of Roman Polygenic Scores].

Intelligence is strongly genetic. Studies of adult identical twins find that it is about 0.8 heritable, meaning 40 percent of the variance in the trait is explained by genetics. Geneticists have identified specific alleles—different forms of genes—that are associated with it. Specifically, they have found alleles strongly associated with being highly educated, and being highly educated is robustly associated with intelligence.

It follows that we would expect the prevalence of these alleles to play an important part in the average intelligence of groups and, indeed, Piffer’s earlier research found a 0.9 (a very strong) correlation between national IQs and the prevalence of these alleles [Correlation between PGS and environmental variables, by David Piffer, RPubs, 2018].

But we can also examine “ancient genomes.” These are broadly representative samples of skeletons from different eras from which DNA has been extracted, potentially allowing us to explore the rise and fall of alleles.

The prevalence is known as the “polygenic score.” We undertook this in our study. We analyzed 127 Ancient Roman genomes, dividing them into pre-Iron Age or Neolithic (10,000 to 2000 BC), Iron Age and Republic (900 to 200 BC), Imperial (0 to 400 AD), Late Antiquity (400 to 700 AD) and Medieval-Early Modern, up to 1770.

Based on the prevalence of these alleles, we found that intelligence increased from the Neolithic Era to the Iron Age. This is consistent with the way in which harsh Darwinian pressures select for intelligence. It also becomes bundled together with other adaptive traits, such as a strong immune system. Based on these polygenic scores, intelligence increased across the Iron Age and Early Republic. So, as we would predict, increasing intelligence in the Roman population went hand-in-hand with the rise of Rome as a Great Power that displaced the Greek City States. Having attained the heights of civilization earlier, those states would have been under weakened selection by this stage.

Everything changed by the arrival of the Imperial Era. This, as any historian will tell you, was unlike the well-ordered, relatively democratic Republic. It was marked by war, internal strife, political instability, and other traits that would be associated with lower average IQ. The end of the Republic was marred by civil war and general chaos, which led to the rise of the Caesars. The prevalence of the alleles showed that intelligence declined in this period.

That’s what one would expect. Rome had become a high civilization, which reduced the correlation between intelligence and how many surviving children people have. An example of the easier conditions the Republic created: the “Cura Annonae,” a government-run program that was initially introduced in 123 BC with a grain law. It provided free or subsidized grain and bread to the poorest 40,000 citizens of Rome. It reached about 200,000 by the time of Augustus (31 BC-14 AD).

And during his time, higher-class men—meaning intelligent men—were increasingly failing to have children, a trend noted by Roman commentators such as Ovid.

Accordingly, Augustus imposed a tax on the childless. But the higher-class men simply paid it.

It is unclear why, in such conditions, intelligent people do not want children. Mortality salience—awareness of one’s eventual death—does increase the desire for children, as I explored in my book The Past is a Future Country, with my co-author J.O.A. Rayner-Hilles. In its absence, intelligent people seem to stop wanting children—something the historian Polybius also noted about Athens in about 200 BC.

With harsher conditions reimposed, and Rome having collapsed into disorder, by Late Antiquity (300-700 AD), intelligence has increased and is about the same as it is today when compared to a sample of contemporary Italian genomes. Early Modern intelligence (Medieval up to 1770) was found to be slightly higher than today, as would be predicted by the harsh conditions under which they lived, including the Mini-Ice Age.

There is, however, another reason for declining Roman intelligence: low-intelligence immigration. During the Imperial Period, immigrants surged into Rome from the periphery of the empire. Some of it, from colder northern areas, may actually have increased average intelligence, but Near Eastern average intelligence was (and is) significantly lower.

When we published this study in July, “I Love Science”-tists—such as U.K. popular scientist Adam Rutherford—roundly mocked it on Twitter, where our study was widely discussed.

Rutherford’s tweet was so manifestly dripping with fallacious arguments and personal vitriol that it is little more than a fascinating insight into the fellow’s personal psychology.

One good point, though made mockingly: Our samples for each era were relatively small. Our counter argument: The level of statistical significance with regard to whether the polygenic scores for each era were genuinely different was 0.02 percent. Over 5 percent is the acceptable standard in science (95 percent confidence). Thus, we can be 99.98% confident that our findings are not a fluke.

If Rutherford won’t accept that, then he shouldn’t fly in airplanes or use modern medicine because he can’t be confident that nothing will go wrong. 

So just before the Roman Empire collapsed, highly intelligent Romans were not having children. Nor did they wish to do so. Add to that mass immigration from places historically subject to far weaker selection pressures for intelligence.

If this reminds you of Europe and the U.S. today—it should.

Edward Dutton (email him | Tweet him) is Professor of Evolutionary Psychology at Asbiro University, Łódź, Poland.  You can see him on his Jolly Heretic video channels on YouTube and Bitchute. His books are available on his home page here.


Print Friendly and PDF