Is human intellect on the downward slide?

So Stanford geneticist Gerald R. Crabtree begins back-to-back Forum pieces for Trends in Genetics, entitled “Our Fragile Intellect” (Parts I and II). Crabtree’s thesis: humanity is “almost certainly” losing its superior intellectual and emotional capacities.

Crabtree doesn’t seem to be arguing for the intellectual vibrancy of the Akademia or the Lyceum. These places, and their celebrated occupants like Plato and Aristotle graced Athens only 600 years later, well beyond Crabtree’s inferred date of humanity’s intellectual zenith.

And he doesn’t confine himself to Athens. “I would also like to make this wager”, he goes on, “for the ancient inhabitants of Africa, Asia, India, or the Americas, of perhaps 2000-6000 years ago.” He’s arguing that humans – throughout the world – have been steadily losing their marbles for the last three to six millenia.

Well, Professor Crabtree, I’ll see your Athenian intellectual Titan. And I’ll raise you a bottle of 1998 St Henri and a $100 book voucher.

Did human intellectual capacity peak 600 years before Plato? Raphael’s Scuola di Atene fresco in the Vatican, 1511. Wikimedia commons

I’m not at all opposed to expansive predictions. But they should be tempered by critical thought. And wherever possible they should be reformulated as hypotheses and tested. Crabtree makes a few predictions that should, with progress in genomics, become testable. But it may surprise you to learn that his argument for why our intellect is fragile doesn’t stand basic scrutiny.

Crabtree’s main point boils down to this: human intellectual function depends on the action of lots of genes. In Part I, Crabtree briefly reviews the evidence that more than ten percent of all human genes – 2000 to 5000 in all – contribute to human intellectual and emotional function.

These genes don’t simply each contribute a tiny bit to intelligence, with the genetic component of any individual’s IQ being the sum of all these minute contributions. Instead, they interact “as links in a chain, failure of any one of which leads to intellectual disability”. The idea that various genes interact is far from controversial. But the case that breaking any one of these genetic links can be catastrophic does not compel me. I am sure that many crucial genes behave this way, but I would be staggered if every one of the 2-5000 was quite so brittle in its functioning.

With so many genes involved, it becomes a mathematic certainty that in the 120 or so generations since the pre-Golden-Age bronze-age “golden age” of the Athenian intellect, “we have all sustained two or more mutations harmful to our intellectual and emotional stability”.

There is some serious genetics behind this argument, and while the conclusions might not follow as crisply as Crabtree argues, it makes for an interesting read on the big-picture state of intelligence genetics. But would selection not have eliminated most of those mistakes?

Crabtree recognises that his case for genetic fragility of the human intellect conceals a flaw: if the human intellect is so fragile, then how could it have evolved to reach the mythic Olympus it inhabited 3000 years ago? In Part II, Crabtree lays out his theory for the main selective forces that shaped human intelligence, and for how changes in the last few thousand years have relaxed that selection. “Extraordinary natural selection”, he argues, “was necessary to optimize and maintain such a large set of intelligence genes”.

And where did that selection come from? Crabtree has some ideas: Errors of judgment. Inability to comprehend the aerodynamics and gyroscopic stabilization of a spear while hunting a large, dangerous animal. Finding adequate food and shelter.

In short, selection happens as a result of not dying. In the kind of world in which merely prevailing over the elements, slaying the occasional mammoth and keeping warm on a cold evening ensured success. The “Survival of the Fittest” world beloved of Darwin’s early supporters. And by creators of museum dioramas.

Which explains why Crabtree thinks humanity’s slide began three millenia before Big Brother even started filming. Agriculture and high-density living, he argued, in selecting for immune resistance to epidemic diseases might have softened selection on intelligence. And that living communally probably reduced the relentless selection by buffering our ancestors from mistakes in judgement and comprehension.

The idea that group living dimmed the harsh selection on day-to-day survival skills intrigues me, and certainly merits testing. But to suggest that this was the end rather than a Renaissance for selection on intelligence reflects a narrow view of how selection works, particularly in humans.

When The Conversation editor, Matt de Neef drew my attention to Crabtree’s articles last week, I was preparing a keynote talk at the Applied Linguistics Association of Australia conference in Perth on the evolution of language. While the deep evolutionary causes by which human capacity for language emerged remain murky and contentions, the ways in which we use language today reveal a lot about the forces that have shaped and embellished our capacity for speech, and for writing and comprehending it.

As societies grew larger and more complex, our social worlds grew apace. More people to interact with every day, to speak with, to manipulate and to avoid being manipulated by. More people to court, and more ardent and eloquent suitors to thwart (or accept). The skills that made our ancestors successful shifted; from survival Bear Grylls style to navigating sexual, social and status complexity Sex and the City style.

A few days ago Jason Collins, made exactly this important point in his excellent blog Evolving Economics:

Humans are complex animals. Our intelligence is a complex adaptation. And the diverse and surprising ways in which we use it today suggest that we owe it to more than a handful of simplistic evolutionary scenarios. Recent evidence suggests that the advent of farming did not halt the course of natural selection, but rather that it diverted it. From where we stand it is almost impossible to discern what directions human evolution, including the evolution of our intellects, might currently be taking.

But I would gladly wage that if humanity is getting dumber it isn’t via natural selection.

This is the crossroads between ancient Sumeria and ancient Assyria ~ it has been occupied by everybody at one time or the other ~ although there are ancient documents about various matters, it is noted in virtually all the detailed histories of the area (even when it was called Armenia ~ this being the ancient Armenian core area) that if you want to know anything about Azerbaijan you have to look up Greek, Roman, Persian, Turkish and other histories.

Zorastrianism was brought in early.

BTW, there's a type of ear called an Armenoid Ear ~ and a nose called an Armenoid Nose. Today both are widespread in the Middle East ~ back in the day even the Hebrews didn't have either!

These folks are also held to be responsible for founding the Median Empire although they are NOT the Medes.

Think of them as a pretty doggone important bunch of people but subject to repeated cultural disaster which has led to them being identified as OTHER PEOPLE!

Thor Hyerdahl worked up an alternative reading of the rather strange stories about Odin found in ancient Norwegian literature. It was his thesis that a group of Azerbaijanis, under the leadership of a guy named Odin, tried to avoid further military service as auxiliaries in the Roman armies so they WENT NORTH TO SCANDINAVIA in the first century BC or thereabouts.

Hyerdahl pointed to a sort of hat and some other features that would be peculiar to these Azerbaijanis and the Norwegians at the time.

Then, one day somebody found a cave in Azerbaijan that showed drawings of the cap and other items of peculiar design that showed up in Norway in the First Century AD.

More recently DNA analysis has shown the presence of Indians in Scotland in ancient times, so it's hardly a surprise to find Azeris wandering off to Norway. They had the horse, iron work, etc.

Way back in the good old days my main Middle Eastern history professor (dr.jwadeh at indiana university) used to use the Azeris as an example of a LOST CIVILIZATION about which we know everything, but we have no idea why since all their stuff is somewhere else. He was the world's foremost expert in the Kurds ~ that is, the Medes.

“No. Culture and learning are in decline, not intelligence, which is innate.”

Perhaps that explains it. Then again, a culture which does not encourage the rigorous application of innate intelligence will seem like the innate intelligence does not exist.

Living overseas for a time, I spoke Spanish fluently as a young boy. I never used it after I returned to the US, and lost it completely.

point is, unexercised, certain aspects of intelligence are indistinguishable from not having possessed the intellect to begin with.

THAT is what we are suffering from - a culture that does not value the effort of pushing one’s intellect to the limit.

Further, the use of automation has also diminished human intellectual accomplishment over time. I look at all the discovery of the past couple hundred years - these folks knew math - they did it in their heads, or on paper. Look at Maxwell, Faraday, Gauss or any of the namesakes of our systems of physical units today - and you find astounding genius in comparison with the “educated class” today.

I think that has something to do with it too.

There are several ethnic groups in Finland. They all speak Finnish, and some of them speak Russian, others Swedish, and yet others Skolt Sa'ami or Northern Sa'ami or even Inari Sa'ami.

Finnish, Estonian and Hungarian are closely related languages. This is a result of history. The Sa'ami languages are NOT closely related as languages go, but they are far more ancient than Finnish, Estonian, Hungarian or the various Indo-European dialects like English, German, Romanian and Tocharian.

For a very long time there's been a debate about whether or not the Sa'ami languages were just variations on Finnish, or had their own source ~ maybe somewhere in the far east. In those days the greatest scientists on earth thought all the Sa'ami originated in the East ~ mostly because of differences in their cheekbones and their eyes ~ like Blond Mongols!

DNA revealed the Sa'ami to be wholly European in origin ~ just the first people to leave the Western European refugia as the Big Ice began melting. They went due North and presumably were heavy into seafood. Eventually they spent the next 19,000 years fairly isolated from other Europeans and retained many features that make them look like the Eastern peoples who split off from the Europeans between 58,000 and 35,000 years back (even the Chinese are not genetically isolated from Europeans more than 35,000 years.)

There was one "meeting" with an outside population about 7,000 to 8,000 years ago so the Eastern Sa'ami managed to pick up some Eastern European DNA ~ and with that managed to introduce some Sa'ami linguistic elements into the blends that ultimately became Hungarian, Estonian and Finnish. Later contact with the Mongols added yet more words to their vocabulary in the 1300s BTW. But even before then, the current thesis is that Sa'ami languages probably lent many of the basic grammatical terms to the less developed Eastern European and Asiatic languages. NOTE: that was all going on before there were any clearly identifiable Indo-European languages.

Within the context of the period from 8,000 years back until about 560 AD, much of the basic Eastern Sa'ami language base got transmitted to East Central Siberia ~ where all the American Indians, East Asians, Japanese, etc. originate. This is in the plains North of the Gobi ~ prime hunting area in the aftermath of the Ice Age.

Not much credit was given to the idea that the Sa'ami actually got that far themselves ~ so the anthropologists had hypothetical East Asian hunters trudging back and forth across the Steppes swapping tusks with the Sa'ami and getting dried reindeer meat in return.

Then within the last 10 years DNA studies revealed a gene sequence called the X-Factor present exclusively in the Sa'ami. Then they found the X-Factor in the Chippewa, then the Cherokee, then the Iroquois, Delaware, Fulbe (in Africa), the Berber (in North Africa), and voila, the Yakuts Sakha in East Central Siberia.

The Yakuts Sakha have a written record recently translated that reports on their recurring invasions of Eastern India, and their returns to Siberia ~ depending on climate, how upset the native got, and so forth, they were there ~ one of their most famous members is known as Buddha. That's why he looks pretty Asian!

About 535 the climate in Western Europe, Eastern Europe, Northern Asia, and a wide variety of other places turned very bad and a Dark Age began in the affected places. Economies collapsed elsewhere.

That's when the Yakuts Sakha traveled East and conquered much of Korea, and much of Japan ~ however, the war in Japan lasted until the 1500s.

I don't think the noble classes in Japan have had their DNA checked for the X-Factor gene sequence, but I wouldn't bet against it being there.

The Yakuts Sakha imposed their Turcic language on Korea and Japan. It has strong elements of the other better known Mongolian languages, but there are Sa'ami words in there ~ just like there are Sa'ami words in all the Indo-European dialects, and all the other Uralic or Altaic languages, particularly Finnish.

Beyond that it's hard to say why lake Inari means a type of sushi in Japanese ~ but it may have to do with FISH.

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