I have always assumed that the Ancients were wiser than us, but I admit that my evaluation is subject to survivor bias: the best of their thinking has been passed on to us, the mediocre rest forgotten. The Ancients were not all at the level of Socrates, they also included the dullards that killed him.

With these reflections in mind, how can we evaluate the ability of ancient peoples? One way is to consider those ancients whose ideas are known to us, and see how well they rank against the current crop of thinkers. To avoid getting enamoured of the chatter of current times, let us stop the clock at 1950, as Charles Murray did in “Human Accomplishment”. Who still gets talked about?

In Western philosophy: Aristotle, Plato, Kant, Descartes and Hegel; in Western literature: Shakespeare, Goethe, Dante, Virgil, Homer; in Sciences: Newton, Galileo, Aristotle, Kepler and Lavoisier; in Mathematics: Euler, Newton, Euclid, Gauss, Fermat.

These thinkers are still revered and their thoughts influence our civilization. How bright were these guys? More to the point, how bright were the ancient populations from which these exceptional thinkers were drawn? How far can we look back at our ancestors? Can we go back as far as the Bronze Age?

Now up comes young Woodley, him of the frock coat who champions the cleverness of Victorians and has a sombre view of quality of current humanity, and tells me of a crafty addition to this debate. By poking about in ancient DNA of which, to my amazement, about 30% can be recovered in some samples, it is possible to hazard a guess as to whether the genes for intelligence have been selected for, that is, whether humans have become brighter. Apparently, yes, we have become brighter, say Woodley of Menie, Younuskunju, Balan and Piffer. Over a very long period, the trend has been upwards. We are superior to our ancestors. However, we will need far more ancient genomes before we can hazard a guess at exactly how many IQ points we have gained since the Bronze Age.

Twin Research and Human Genetics Volume 20, Number 4, 2017 doi:10.1017/thg.2017.37
Holocene Selection for Variants Associated With General Cognitive Ability: Comparing Ancient and Modern Genomes
Michael A. Woodley of Menie,1,2 Shameem Younuskunju,3 Bipin Balan,4 and Davide Piffer5,†

1 Unz Foundation, Palo Alto, CA, USA
2 Center Leo Apostel for Interdisciplinary Studies, Vrije Universiteit Brussel, Brussels, Belgium
3 Weill Cornell Medicine, Cornell University, Dohar, Qatar
4 Department of Agriculture and Forestry Science, University of Palermo, Palermo Italy
5 Department of Psychology, Ben Gurion University of the Negev, Beer-Sheva, Israel

http://www.biorxiv.org/content/early/2017/02/20/109678

Since the rise of agriculture about four and a half thousand years ago, humans living in Europe and Asia have increased in cognitive ability. The authors base their argument on the study of 99 ancient Eurasian genomes (from 4.56 to 1.21 thousand years ago) which they compare to the genomes of 503 modern Eurasians. Using three different way of calculating the genetic code scores, they find that all three show advantages for modern humans. These three scores are better than 80% of control measures of random genome scores, showing that they are highly likely to have picked up real improvement in intelligence. They checked this on a sub-sample of 66 ancient genomes for which carbon dating was available, and found that their method correlated significantly with this sample. Far from evolution slowing up as our ancestors became farmers, it seems to have speeded up selection for problem solving capacity.

Here is their abstract:

Human populations living in Eurasia during the Holocene underwent considerable micro-evolutionary change. It has been theorized that the transition of Holocene populations into agrarianism and urbanization brought about culture-gene co-evolution that favored via directional selection genetic variants associated with higher general cognitive ability (GCA). To examine whether GCA might have risen during the Holocene, we compare a sample of 99 ancient Eurasian genomes (ranging from 4.56 to 1.21 kyr BP) with a sample of 503 modern European genomes (Fst = 0.013), using three different cognitive polygenic scores. Significant differences favoring the modern genomes were found for all three polygenic scores (odds ratios = 0.92, p = .037; .81, p = .001; and .81, p = .02). These polygenic scores also outperformed the majority of scores assembled from random SNPs generated via a Monte Carlo model (between 76.4% and 84.6%). Furthermore, an indication of increasing positive allele count over 3.25 kyr was found using a subsample of 66 ancient genomes (r = 0.22, pone-tailed = .04). These observations are consistent with the expectation that GCA rose during the Holocene.

The authors point out that selection for intelligence increases when humans move from familiar to novel environments, in which new thinking is required. Old established routines, possibly even those hard-wired like the detection of cheats, no longer cope with novelty and changeable environments.

Instead, such problems require generalized and open-ended problem-solving systems, such as learning and working memory, in order to tailor solutions to them. The ability to innovate a solution to such a problem (via the development of a tool) is a key manifestation of the action of these generalized problem-solving systems (Geary, 2005).

Innovations that played a major role in facilitating this transition would have included the domestication of cultivars and animals and the development of novel tools for raising the productivity of land (such as the plough; Cochran and Harpending, 2009). Cultural innovations such as monotheism, monarchy, aristocracy, feudalism, and currency-based economics arose in response to the need for coping with the hierarchical power distribution characteristic of large, static populations (Cochran and Harpending, 2009).

A number of things arise from this finding. In European and Central Asian biomes at least there is evidence of selection for intelligence. The effect is slight but positive: the intellectual tone is improving. Bronze Age humans may have moved towards slow life histories: more long term, considered, restrained lives. Wisdom, you might say. However, although we are brighter than the ancients, we are probably not as bright as the Victorians. In fact, we have probably passed our peak.

Here’s why:

Selection operating over the course of millennia (as in the present case) would be expected to produce quite considerable micro-evolutionary change. As was discussed in the section Introduction, Holocene populations appear to have undergone accelerated adaptive micro-evolution relative to those living in the Pleistocene (Cochran & Harpending, 2009; Hawks et al., 2007). Increasing cultural complexity and technological sophistication among these populations may therefore have arisen in part from selection favoring GCA. Cultural and technological change can in turn create, via culture-gene co-evolutionary feedback, conditions favoring higher GCA (Cochran & Harpending, 2009; Piffer, 2013).

This process likely continued until the Late Modern Era, where it has been noted that among Western populations living between the 15th and early 19th centuries, those with higher social status (which shares genetic variance with, and is therefore a proxy for GCA; Trzaskowski et al., 2014) typically produced the most surviving offspring. These in turn tended toward downward social mobility due to intense competition, replacing the reproductively unsuccessful low-status stratum and effectively ‘bootstrapping’ those populations via the application of high levels of skill to solving problems associated with production and industry, eventually leading to the Industrial Revolution in Europe (Clark, 2007 2014). The millennia-long micro-evolutionary trend favoring higher GCA not only ceased, but likely went into reverse among European-derived populations living in the 19th century (Lynn, 1996; Lynn & Van Court, 2004), largely in response to factors such as the asymmetric use of birth control and prolonged exposure to education among those with high GCA (Lynn, 1996). Consistent with this, it has been found that various POLYCOG negatively predict reproductive success in contemporary Western populations (Beauchamp, 2016; Conley et al., 2016; Kong et al., 2017;Woodley of Menie, Schwartz et al., 2016). It is important to note that this recent micro-evolutionary trend (working in the opposite direction) has likely attenuated the difference in POLYCOG between the modern and ancient genomes noted in the present study.

In other words, if we had been caught in our Victorian prime our rise in ability since the pre-agricultural hunter-gatherer ages would have been even more apparent. Selection is the key. When you must use your wits to survive, and restrain present urges for future gains, then the brighter multiply. When, in less taxing circumstances, there is no particular need for wit or restraint, then there is no premium for those characteristics.