Polygenic
scores for alleles associated with educational attainment - Europeans of
different time periods (Kuijpers et al. 2022)
According
to a new study of ancient European DNA, cognitive evolution stagnated after the
last ice age and then speeded up with the rise of farming. It stagnated again
during Antiquity and then speeded up again sometime between then and now.
In
my last post, I mentioned an ancient DNA study of 99 genomes from sites across
Europe and Central Asia. It showed an apparent increase in mean cognitive
ability between 4,560 and 1,210 years ago, as measured by alleles associated
with educational attainment (Woodley et al. 2017).
That
finding has been partially replicated by a new study of 827 genomes from
ancient European remains and 250 genomes from modern Europeans. It looks like
cognitive evolution stagnated after the last ice age and then speeded up with
the rise of farming. It stagnated again during Antiquity and then speeded up
again sometime between then and now:
Interestingly, while the period between
the Early Upper Paleolithic and the Neolithic is characterized by stagnation or
slight decrease in PRS related to intelligence, the genetic data show a clear
increase in the scores for educational attainment, intelligence, and fluid intelligence
from the Neolithic onwards, while the traits related with unipolar depression
tend to decrease from that era on. The most significant differences can be
observed comparing the pre-Neolithic and Neolithic groups, as well as the
post-Neolithic and modern groups, whereas the period between the Neolithic and
post-Neolithic shows a very constant distribution of PRS scores. (Kuijpers et
al. 2022).
The
authors define the time periods as follows:
Early
Upper Paleolithic era – before 28,000 years BC
Late
Upper Paleolithic era – 28,000 to 11,000 BC
Mesolithic
- 11,000 to 5500 BC
Neolithic
- 8,500 to 3900 BC
Post-Neolithic
- 5000 BC and more recent ages (no end date given)
Modern
– circa 1950 AD
The
Mesolithic, the Neolithic, and the Post-Neolithic overlap a lot with each other.
This is because their boundaries are defined by cultural changes that came to
different parts of Europe at different times. The Neolithic began when hunting
and gathering gave way to farming, which came later to northern Europe.
Similarly, the post-Neolithic began with the advent of metallurgy, which
likewise came later to northern Europe.
Such
overlap is problematic for three reasons:
·
In
some cases, there is uncertainty as to whether the ancient DNA came from the
remains of hunter-gatherers or those of farmers.
·
“Hunter-gatherer”
is not a homogeneous category. It includes not only small nomadic groups but
also the hunter-fisher-gatherers of the Baltic and North Sea, who attained a
degree of sedentism, population growth, and social complexity that we normally
associate with farmers (Price 1991).
·
The
Post-Neolithic is too long to be meaningful. It covers all of recorded history,
and then some.
The
study’s authors could have divided the Post-Neolithic into smaller time periods
to give us a better look at changes during historical times. In particular, did
cognitive evolution regress during Classical Antiquity? That was the
preliminary finding of a team led by Michael Woodley of Menie (2019) in a study
of ancient DNA from Greece. They found that mean cognitive ability increased
from the Neolithic to the Mycenaean period and then decreased sometime between the
latter and the present day. That study was never published, perhaps because the
geographic area and the time periods were too small to provide robust results.
To
get more robust results, we could look at ancient DNA from the entire
Greco-Roman world, perhaps divided into three time periods: 5000 to 1000 BC;
1000 to 0 BC; and 0 to 500 AD. Was there a large increase in mean cognitive
ability followed by an equally large decrease? Or was there simply a long
period of stagnant evolution?
In
a previous post, I argued that the culture of Classical Antiquity, particularly
in its later stages, caused cognitive evolution to regress (Frost 2022). There
were several reasons:
·
A
decline in fertility and family formation, particularly among the upper
classes;
·
A
corresponding increase in female hypergamy, often by freed slaves, which
reduced the reproductive importance of upper-class women;
·
An
increase in the foreign slave population, which disrupted cognitive evolution
within the local population. Even if there had been demographic overflow from
the upper classes, that overflow could not have replaced the lower classes,
since those classes were being replaced from external sources.
We
need a clearer picture. According to the current data, it looks like cognitive
evolution simply stagnated during the Post-Neolithic, but I suspect that time period
is so broadly defined that it conceals a regression during the centuries before
the fifth century collapse and the centuries immediately after.
References
Frost, P. (2022). When did Europe pull ahead? Evo and Proud, May 16. http://evoandproud.blogspot.com/2022/05/when-did-europe-pull-ahead.html
Kuijpers,
Y., J. Domínguez-Andrés, O.B. Bakker, M.K. Gupta, M. Grasshoff, C.J. Xu,
Joosten LAB, J. Bertranpetit, M.G. Netea, and Y. Li. (2022). Evolutionary
Trajectories of Complex Traits in European Populations of Modern Humans. Frontiers in Genetics 13: 833190. https://doi.org/10.3389/fgene.2022.833190
Price,
T.D. (1991). The Mesolithic of Northern Europe. Annual Review of Anthropology,
20, 211-233. Price,
T. D. (1983). The European Mesolithic. American
Antiquity 48(4), 761–778. https://doi.org/10.2307/279775
Woodley,
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. https://doi.org/10.1017/thg.2017.37
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
14 comments:
Athens?
Eugenics=/=social Darwinism
Why is female hypergamy in itself bad? If lower status women have children with upper status men instead of men of their own class, isn't that eugenic? (Unless those couples have correspondingly more children than upper status women-upper status men couples)
Sean,
Please elaborate.
Santocool,
Not sure I understand your mathematical notation.
Yeong,
Female hypergamy has a neutral impact on cognitive evolution in a situation where natural increase is the same for all social classes. Cognitive evolution is hindered, however, in a situation where the the higher social class has a higher rate of natural increase, as was the case in England between the 11th and 19th centuries (see Gregory Clark) and in China for most of its history (see Ron Unz). In that situation, female hypergamy will slow down or stop cognitive evolution.
In other words, female hypergamy tends to blur the cognitive difference between higher and lower classes. Although there is still demographic replacement of the lower class by the higher class, the evolutionary consequence is less significant. Overall, there is less change in mean IQ with each generation.
Not sure you know what eugenics is. Maybe your fat wife knows.
Hi Santocool,
I was confused by your mathematical sign "=/=". The slash across the equal sign seems to mean "does not equal." But that might not be what you mean.
Irina's been losing weight. She looks great now.
what we should not dismiss in that picture of decreasing IQ in late antiquity is the impact of socially tolerated or even promoted homosexuality - especially amongst the upper (slaveholder) class. if more intelligent men live their life according to gay standards, they cut themselves off from the gene-pool. whilst women turn either also to lesbianism or chose les intelligent males from the lower strata (s. the reported faible of roman patrician women for gladiators:)) - or both sexes turn to kind of celitaire lifestyles - growth of monastery lifestyles in late roman empire.
parallels with recent societies are striking.
Social Darwinism is the equivalent of economic liberalism. In fact, one tends to cause the other. It is the minimized presence of the state to moderate socio-economic and cultural relations.
Eugenics is equivalent to socialism or a greater state presence, which would be needed to ''guide'' a population towards its designs.
Oh, sorry. I deduced the rising sarcasm from some of your replies to my comments.
''what we should not dismiss in that picture of decreasing IQ in late antiquity is the impact of socially tolerated or even promoted homosexuality - especially amongst the upper (slaveholder) class. if more intelligent men live their life according to gay standards, they cut themselves off from the gene-pool. whilst women turn either also to lesbianism or chose les intelligent males from the lower strata (s. the reported faible of roman patrician women for gladiators:)) - or both sexes turn to kind of celitaire lifestyles - growth of monastery lifestyles in late roman empire.
parallels with recent societies are striking.''
There is no real eugenics, in its most ideal sense, than eliminating sociopaths and psychopaths, who are most responsible for human problems.
In fact, apart from that, eliminating predispositions for serious illnesses and raising the RATIONALITY level of the population would be enough.
As for your hypothesis.
Are you conclusively concluding that there is a significant disproportion of LGBTs among the most ''intelligent''??
Why do you think people in developed countries and even underdeveloped countries, the most educated, are having fewer children?
Is it because a minority of the population adopts certain behaviors??
No, there are two factors and they are totally linked to capitalism:
-Increase in the cost of living, especially in urban centers, mainly caused by the gentrification of the most central areas of cities;
-Materialism: even people with a good standard of living tend to prefer the senseless accumulation of an exaggerated amount of material goods [which will further pollute the environment].
This further influences women to avoid relationships with men that they consider to be of ''lower value''.
Yes, there appears to be a disproportion of highly ''smart'' LGBTs, but it is unlikely that they are more than 10 or 20% of the ''smartest'' population.
You wanted to establish a causal relationship where there is a coincidence.
When a civilization, if otherwise more conservative, becomes more liberal, because of the very instability of great empires, it has tended from one extreme to the other.
But in the case of antiquity, at least in Ancient Greece, partial tolerance of homosexual recreational practices, associated with extreme amisogyny, especially in Athens, does not seem to be the case.
Furthermore, speaking of parallel coincidences or correlations, and intersectional correlations, this relationship between homosexuality and classical Greece is interesting, especially in its more developed city-state.
Santocool,
I wasn't being sarcastic. Sometimes I really have trouble understanding your argument. Sorry.
Anon
Exclusive homosexuality was rare in the ancient world. Once a man had children by his wife, he had performed his duties to his ancestors and could engage in recreational sex of any sort.
The low or negative rate of natural increase during Greco-Roman Antiquity seems to have had several causes:
- a high rate of mortality, especially in urban environments
- a low rate of marriage, possibly because of the costs
- an erosion of traditional supports for marriage and family formation
- increasing reliance on foreign slaves, foreign mercenaries, etc., all of which provided an immediate solution to the problems of demographic decline within the native population
both santocool and peter frost missing the point I tried to make, imho.
of course, the majority of gays are dumb as the average population :))
but if the smart percentage of gays represents 10-20 % of the smartest male YOUNGSTERS (i.e. those who should procreate with the smartest 'elite' girls of their society in order to maintain/elevate the IQ of their class and thus the entire population), then we will experience a slow but steady decline in IQ. remember, roman empire was expanding till it adopted the thouroughly pro-gay culture of decadent hellenism (in the words of roman ruling senators) at the end of the republic - still expanding/conquering and exploting till the long crisis in mid 2nd century a.d. - only then stagnating and declining.
the gay-effect took its time to mature - about 2-300 years (mere 10 generations).
gay young upper classers did not marry or marry late, not because marriage was expansive, but simply because they were not that interested as hetero young males. if they were forced to do, the most likely outcome would be that their wives had their children from intercourse with their slave-lovers or gladiators (famous sportsmen of their time) - mentioned in almost all biographies of imperial families (by suetonius, eg.)
...
one can blame capitalism for many things, but certainly not for the downfall of the roman empire! :))
what especially in the case of the roman empire never should be forgotten, is the cultural impact of christianity: on the one hand brutally homophobic and anti-gay (deadly sin for all believers), on the other providing with the propagation of a monastic, ascetic, asexual lifestyle in monasteries an outlet for all who wanted to escape from the burden of hetero family raising/lifestyle.
It's unlikely as i said and the biggest problem are the heterossexual smartest population who don't procreate or have too few children, mostly because is too expensive.
Roman empire fall by the same way all Empires did: megalomaniacal greed. Roman empire wasn't capitalist formally speaking but there were social inequalities, exploitation of the working classes and materialistic lifestyle among the "elites".
Cristianism has been a huge problem to the real cultural, scientific/philosophical and social progress in Europe and then in extended "western world" no matter how beautiful its churches can be, it's a frivolous aesthetics.
But do you really think all priests and nuns were or are very obedient???
The "aesthetic" of christianity or any other "religion" is based on the denial of the reality of singularity and finitude of life...
reply to Yeong
the main problem with hypergamy is the majority of women and orbiting and reproducing with a small selection (like 10%) of the men.
You get a huge number of forceful celibates, with no prospects of marrying.
This pushes society to become more violente on a side, males less productive (why works so much if you don't leave anything to any descendant?).
The males in excess can be exploited as warriors in wars, but this depleted the good candidates to reproduction and leave the worse back home.
Interesting how Japan and other far east countries have so many incels and not a noticiable increase of crime by males. Meanwhile, subsaharian africa still has a higher fertility rates but crime rates there is often high.
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