Saturday, July 13, 2019

The Golden Age of Intelligence?

Busts of Greek philosophers (Wikicommons, Matt Neale). Did the Ancient Greeks have the highest mean IQ of any human population then and since?

Francis Galton argued that average intelligence had been much higher in ancient Greece than in modern England. He came to this conclusion after comparing the proportion of eminent men in Athens of the fifth century BC with the proportion of eminent men in the England of his day:

It follows from all this, that the average ability of the Athenian race is, on the lowest possible estimate, very nearly two grades higher than our own-that is, about as much as our race is above that of the African negro.(Galton 1869, p. 342)

This high ability was then presumably lost:

We know, and may guess something more, of the reason why this marvellously-gifted race declined. Social morality grew exceedingly lax; marriage became unfashionable, and was avoided; many of the more ambitious and accomplished women were avowed courtesans, and consequently infertile, and the mothers of the incoming population were of a heterogeneous class. (Galton 1869, pp. 342-343)

If we accept Galton's reasoning, Ancient Greeks had the highest mean IQ of any human population, something like 120 or 125. By comparison, Ashkenazi Jews have an estimated mean IQ of 110. But was Galton right? His calculations were criticized at the time, specifically for underestimating the number of Athenian citizens. He consequently revised his calculation downward to 1.5 grades higher, i.e., a mean IQ of 115 to 119 (Challis 2013, p. 56).

That's still impressive. But higher IQ doesn't necessarily imply higher innate intelligence. Conditions in ancient Greece may have simply been better for intellectual discussion, such activity being respected as an activity in its own right. By comparison, intellectual discussion was much more circumscribed in the ancient Middle East, where it was confined to specific people who performed specific duties, most often writing and copying texts at the request of others.

Admittedly, this explanation does not exclude a genetic one. If the cultural environment favors intellectual development, it will tend to reward the most promising people with reproductive success. A scribe is thus praised in a Jewish wisdom book from the second century BC: "Many will praise his understanding; it will never be blotted out. His memory will not disappear, and his name will live through all generations. Nations will speak of his wisdom, and the congregation will proclaim his praise. If he lives long, he will leave a name greater than a thousand." Book of Sirach [39.1-11].

In the ancient world, 'leaving a great name' did not mean being written about by historians but rather having many illustrious children to carry on the family name long after death. Intellectual ability thus co-evolved with a supportive cultural base. Indeed, we humans have co-evolved much more with our cultural environment than with our natural environment (Hawks et al. 2007).

A new yardstick

Galton's conjecture can now be tested with two new research tools:

1. Ancient DNA. Large quantities of genetic data have been collected from ancient human remains and are now being made available to researchers. This year, the Reich lab at the Harvard Medical School released over 2,000 ancient genomes, including 30 from ancient Greece.

2. Polygenic cognitive score. Some gene loci are associated with differences in educational attainment. By examining the variants at these loci and by adding up the ones associated with higher educational attainment, we can calculate a polygenic score that correlates with mean IQ (r = 0.98).

By examining 102 ancient genomes, a research team led by Michael Woodley of Menie was able to chart the evolution of cognitive ability in Europe and Central Asia. His team found that genetic variants for higher educational attainment gradually increased in frequency from 4,560 to 1,210 years ago (Woodley of Menie et al. 2017). Now, with newly released data from the Reich lab, he is leading a research effort to look specifically at ancient Greeks. The results are still preliminary, but they indicate a progressive increase in the polygenic score from Neolithic to Mycenaean times, followed by a decrease. When? We don't know because we lack post-Mycenaean data (Woodley of Menie et al. 2019).

More to come ...

This is a promising avenue for research. In particular, we need:

- A larger sample of modern Greek genomes. This should not be difficult.

- Samples from post-Mycenaean times to the end of Ottoman rule. Was Galton right in placing this cognitive decline during the ensuing Hellenistic and Roman periods? Or did it happen over a longer span of time?

The final published paper should explain at greater length the research team's use of a restricted polygenic score, i.e., a polygenic score based only on those genetic variants that seem causally related to high educational attainment, and not simply associated with high educational attainment. This approach is acceptable if a third party had identified these variants; otherwise, there is a risk of focusing on those variants that support Galton's hypothesis.

Another point: in the presentation of his new project, Woodley of Menie spoke repeatedly about population replacement at various times in the history of ancient Greece (Woodley of Menie et al. 2019). Yet the current thinking is that immigration was historically unimportant in Greece. Present-day Greeks are largely descended from the Mycenaeans, with some later introgression by Slavic tribes and other peoples (Gibbons 2017; Stamatoyannopoulos et al. 2017).

This research is especially exciting because the Reich lab released ancient DNA data not only from ancient Greece but also from elsewhere. History may end up being seen in a new light. For instance:

- Rome probably went through a similar increase in mean intelligence, followed by decline. When did the decline begin? During the collapse of the fifth century? I suspect earlier, perhaps in the third century. The barbarian invasions were both a cause and effect in the collapse of Roman civilization.

- The Enlightenment was due only in part to things like the invention of the printing press, the voyages of discovery, and the founding of universities. These were subsidiary causes that resulted from and supported a more fundamental change: a steady increase in the smart fraction of European societies—the proportion of people who enjoy reading, writing and, above all, thinking.


Angel, J.L. (1950). Population size and microevolution in Greece. Cold Spring Harbor Symposia on Quantitative Biology 15: 343-351. doi:10.1101/SQB.1950.015.01.031

Challis, D. (2013). The Archaeology of Race. The Eugenic Ideas of Francis Galton and Flinders Petrie. London: Bloomsbury. 

Galton, F. (1869). Hereditary Genius: An Inquiry into Its Laws and Consequences. London: MacMillan.

Gibbons, A. (2017). The Greeks really do have near-mythical origins, ancient DNA reveals. Science August 2 

Hawks, J., E.T. Wang, G.M. Cochran, H.C. Harpending, and R.K. Moyzis. (2007). Recent acceleration of human adaptive evolution. Proceedings of the National Academy of Sciences (USA) 104: 20753-20758.  
Stamatoyannopoulos, G., A. Bose, A. Teodosiadis, F. Tsetsos, A. Plantinga, N. Psatha, N. Zogas, E. Yannaki, P. Zalloua, K.K. Kidd, B.L. Browning, J. Stamatoyannopoulos, P. Paschou, P. Drineas et al. (2017). Genetics of the peloponnesean populations and the theory of extinction of the medieval peloponnesean Greeks. European Journal of Human Genetics 25: 637-645. 

Woodley of Menie, M.A., S. Younuskunju, B. Balan, and D. Piffer. (2017). Holocene selection for variants associated with general cognitive ability: Comparing ancient and modern genomes. Twin Research and Human Genetics 20: 271-280

Woodley of Menie, M.A., J. Delhez, M. Peñaherrera-Aguirre, and E.O.W. Kirkegaard. (2019). Cognitive archeogenetics of ancient and modern Greeks. London Conference on Intelligence 


Sid said...

I do think it's highly likely the Ancient Greeks had unusually high intelligence because of genetic reasons. Their achievements dwarfed those of surrounding populations and remain impressive to this day. Has anyone written a screenplay better than Antigone? No.

Greece also saw a long rather than a sudden decline. For example, the Greek branch of Christian theology was notably more abstract and intricate than the Latin one in the time of the Early Church. I'd say Greece stopped being on the cutting edge of thought after the Arabic conquest of the Middle East and the start of the Byzantine Dark Age. The Greeks lost their politico-military importance after the Fourth Crusade, and Greece has since largely been a backwater in most every regard since then.

What's challenging is determining what exactly caused Greek intellect to rise so far beyond those of Greece's peers. One issue is that I don't think we have much of an idea of what the Greek Dark Age was like. The pre-Indo-European Aegean and Minoan civilizations are architecturally and artistically impressive, so I can believe they also had high intelligence even before the Greek language was spoken there, but their literature and language is virtually unknown to us.

Sean said...

Emigration? Athens was a trading sea power that established colonies.

Galton thought the peak of Ancient Greek intelligence was epitomized by the free born population of Attica in the century begining 530 BC

Until the 6th century BC, aristocratic families lived independent lives in the suburbs. Only after Peisistratos's tyranny and the reforms implemented by Cleisthenes did the local communities lose their independence and succumb to the central government in Athens."

Anonymous said...

OntheSly said...

Did those 30 genomes from Ancient Greece answer the question as to what race they were?

I'm not a Nordicist (I'm actually a Med) and I'm aware Greek pottery all shows them as fairly dark eyed and dark haired. And I know they've found that ancient Minoans are more closely related to modern Minoans than any other group. But I have to admit that all those people and godesses described as light-haired or light-eyed in Ancient Greek texts is a little jarring. So I could never rule out the possibility that the Ancient Greeks were diverse, with a significant Nordic or at least fairer population somewhere in there. Was wondering if the thirty genomes turned up any of that.

Eugen said...


Have you read this article about ancient Greeks?

I also used to wonder about "blonde" Achilles and Menelaus in the Iliad and so on, but it pretty much convinced me that Nordicism is wrong about ancient Greeks. The gist is that the word used there didn't mean "blonde", but was used for any color that isn't straight up black. On top of that, other forms of that word were used to describe roasting meat and eye color, which probably means that Greeks usually used it describe some shade of brown.

Santo said...

Philosopher greeks often reffered the ''greek type'' as the ideal, between the northern pale and the southern tanned.. but i don't know how if is related with skin color [many slavs, germs and nords can tan the skin in the summer, considerably more than brits] or with general body complexion. Maybe, ancient greeks were, racially speaking, just like still-european french and hungarians, a very subracial mixed group. Also, the mix between earlier minoan civilization with northern invasors may created a kind of ''hybrid vigor'', combining the ''mediterranean'' skill to civilization with military/warrior dorian skill.

Open to experience genetic variation mostly differentiate creative, cosmopolitan and artistic Athens with boringly militaresque Sparta.

Commercial or naval civilizations often require creativity/flexibility skills.

Just remember the phoenitian civilization.

Santo said...

''with'' [over]

Anonymous said...

It is very easy to verify genetic continuity between the Mycenean, Archaic, Classical or Hellenistic greeks with today's greeks with modern genetic methods. There are enough ancient tombs found of every era with intact skeletons.
who seem to represent the Cylonian affair ( coup ) guys.

So far all studies show that there is a continuity with minimal admixture. Which btw perfectly matches the known history. I mean as far as we know ( while there has been persecution of pagans in the 4th to 6th century AD by the christians) there was no genocide, massive dislocation or migration in the area.
It seems that nurture is more important than nature/dna ( though I do not underestimate the effects of dysgenic fertility). In other words the circumstances and conditions of ancient Greece allowed and encouraged the existence of geniuses. As soon as christianity became the major religion with persecution of the greek paganists ( mostly by Theodosius), the closure of academy of Plato, banning of Olympics, destruction of temples etc the conditions ceased to exist. Keep in mind at up untill the 3d century AD Greece was still producing geniuses * under roman rule in all fields of science.