How real is the Flynn effect? Part II

 

Can you pass a Grade 8 exam that was given to American children in 1912? Why the Flynn effect never really happened.

 

 

My last post elicited a tweet from Elon Bachman:

 

Argument by incredulity (w.r.t. retardation) bedevils discussions of intelligence data. What's striking about most retards is the *congenital* speech & motor impairment, not the level of g. Height also increased 1 SD last century. There used to be a lot of malnourished peasants. @ElonBachman

 

In a population with an average IQ of 100, an IQ below 70 is usually due to abnormal circumstances, either freak accidents during pregnancy or rare mutations that haven’t been eliminated by natural selection. In either case, the adverse effects are wide-ranging and affect many aspects of mind and behavior. If your IQ is below 70, you’re lacking in much more than cognitive ability. You probably suffer from various speech and motor impairments. In short, you look and act “funny.”

 

A century ago, if we use current norming of IQ tests, average IQ was below 70 in the Western world. Yet it was not associated with looking and acting “funny.” How come?  For Elon Bachman, this is because an IQ of 70 was normal back then. It was not an outcome of freak accidents or rare mutations. The mental deficit was therefore confined to cognitive ability alone.

 

I understand that argument. Nonetheless, the increase in IQ between then and now is still 35 points—more than two standard deviations. Such a difference in cognitive ability should be visible in popular culture, particularly the books and newspapers that people read. It should also be visible in the academic requirements of elementary school, which was compulsory by that time in most North American jurisdictions.

 

The following are some questions from a Grade 8 exam that was given in 1912 to children in Bullitt County, Kentucky:

 

Find cost at 12½ cents per sq. yd. of kalsomining the walls of a room 20 ft. long, 16 ft. wide and 9 ft. high, deducting 1 door 8 ft. by 4 ft. 6 in. and 2 windows 5 ft. by 3 ft. 6 in. each.

 

A man sold a watch for $180 and lost 16 2/3%. What was the cost of the watch?

 

How many parts of speech are there? Define each.

 

What is a personal pronoun? Decline I.

 

Define longitude and latitude.

 

Tell what you know of the Gulf Stream.

 

Through what waters would a vessel pass in going from England through the Suez Canal to Manila?

 

Compare arteries and veins as to function. Where is the blood carried to be purified?

 

Define Cerebrum; Cerebellum.

 

Define the following forms of government: Democracy, Limited Monarchy, Absolute Monarchy, Republic. Give examples of each.

 

Name five county officers and the principal duties of each.

 

What is a copyright? Patent right?

 

Describe the Battle of Quebec.

 

Name the last battle of the Civil War; War of 1812; French and Indian War and the commanders in each battle.

 

Those are only a few of the questions. The full exam is here.

 

I understand why some want to believe that Western societies were much less intelligent a century ago. If we cannot use IQ to compare different populations over time, perhaps we cannot use it to compare different populations over space, i.e., in different parts of the world. And then what?

 

I’ve heard that sort of argument before. “If we accept genetic determinism for this, we may have to accept it for that. And then what?” If that’s your frame of mind, I have nothing more to say.

 

The increase in IQ and the increase in height during the 20th century

 

But what about the increase in height? That was real. If insufficient nutrition held back height during the 20th century, it should have also held back cognitive ability. The assumption here is that IQ and height are equally constrained by nutrition during development. Has that assumption been tested?

 

It has. The Dutch suffered a terrible famine during the winter of 1944-1945, as did much of continental Europe. Yet that famine had no discernable impact on the mental development of unborn children from that time:

 

A detailed retrospective study was made of 125,000 19-yr-old male Dutch military inductees of whom 20,000 were exposed to the Netherland's winter famine, 1944-1945, through maternal starvation. […] Findings show that (a) starvation during pregnancy had no detectable effects on adult mental performance of surviving male offspring. (b) Mental performance of surviving adult males from the entire population had no association with changing levels of mean birth weight in a hospital sample from the population. And (c) there was a strong association of social class with mental performance. (Stein et al. 1972)

 

It isn’t as if the Flynn effect didn’t occur in the Netherlands, As James Flynn points out:

 

As for nutrition, to my knowledge no one has actually shown that American or British or Western European children have a better diet today than they did in 1950, indeed, the critics of junk food argue that diets are worse. Yet, post-1950 IQ gains have been very large. Military samples tested in 1952, 1962, 1972, and 1982 show that Dutch males made a 20-point gain on a Raven’s-type test (Flynn, 1987, p. 172). Even the latest period shows a huge gain, that is, the Dutch 18-year olds tested in 1982 outscored the Dutch 18-year olds tested in 1972 by fully 8 IQ points. Did the quality of the Dutch diet really escalate that much in 10 years? The gains posted by the 1962 males over the 1952 males are interesting. (Flynn 2008)

 

Those 1962 males were born or still in the womb during the 1944-45 famine. Yet they “do not show up even as a blip in the pattern of Dutch IQ gains” (Flynn 2008). One could argue that the famine was too brief to affect cognitive ability. Perhaps malnutrition needs a longer time span to affect mental development. And again, what about the increase in height? What was driving that increase?

 

We don’t know for sure. We do know that height increased independently of the increase in IQ.

 

Norway was cited above as a nation in which the nutrition hypothesis is viable thanks to greater gains in the lower half of the IQ distribution. Actually, it counts against the posited connection between height gains and IQ gains. Height gains have been larger in the upper half of the height distribution than in the lower half (Sundet et al., 2004). This combination, greater height gains in the upper half of the distribution, greater IQ gains in the lower, poses a serious problem. Are there two kinds of enhanced nutrition, one of which raises height more than it does IQ, the other of which raises IQ more than it does height? (Flynn 2008)

 

There is no common cause behind the increase in IQ and the increase in height. The latter seems to be due to people eating a more varied diet after the Second World War. In particular, fewer and fewer people were subsisting largely on bread. That food item is problematic not only because it lacks many nutrients but also because it has a high content of phytic acid, which binds to calcium and other essential minerals in the food we eat (Harrison and Mellanby 1939; McCance and Widdowson 1942a; McCance and Widdowson 1942b; Sandstead 1992). With the postwar boom, and with efforts to educate people about the benefits of a balanced diet, bread made up a smaller and smaller proportion of total food intake. Bones could now fully develop.

 

Excessive consumption of bread, and the resulting lack of essential minerals, constrained skeletal development during the early 20th century. But it did not constrain cognitive ability.

 

References

 

Flynn, J.R. (2008). Requiem for nutrition as the cause of IQ gains: Raven's gains in Britain 1938-2008. Economics and Human Biology 7(1):18-27. https://doi.org/10.1016/j.ehb.2009.01.009

 

Harrison, D.C., and E. Mellanby. (1939). Phytic acid and the rickets-producing action of cereals. Biochemical Journal 33: 1660-1680. https://doi.org/10.1042%2Fbj0331660

 

McCance, R.A., and E.M. Widdowson. (1942a). Mineral metabolism of healthy adults on white and brown bread dietaries. The Journal of Physiology 101: 44-85. https://doi.org/10.1113%2Fjphysiol.1942.sp003967

 

McCance, R.A., and E.M. Widdowson. (1942b). Mineral metabolism on dephytinized bread. The Journal of Physiology 101: 304-313. https://doi.org/10.1113%2Fjphysiol.1942.sp003984

 

Sandstead, H.H. (1992). Fiber, phytates, and mineral nutrition. Nutrition Reviews 50: 30-31. https://doi.org/10.1111/j.1753-4887.1992.tb02464.x

 

Sieczkowksi, C. (2013). 1912 Eighth-Grade Exam Stumps 21st-Century Test Takers. Could You Pass This Eighth-Grade Exam from 1912? Huffpost, August 12. https://www.huffpost.com/entry/1912-eighth-grade-exam_n_3744163

 

Stein, Z., M. Susser, G. Saenger, and F. Marolla. (1972). Nutrition and mental performance. Science 178(4062): 708–713. https://doi.org/10.1126/science.178.4062.708

 

Sundet, J.M., D.G. Barlaug, and T.M. Torjussen. (2004). The end of the Flynn effect? A study of secular trends in mean intelligence test scores of Norwegian conscripts during half a century. Intelligence 32: 349– 362. https://doi.org/10.1016/j.intell.2004.06.004

 

 

 

 

How real is the Flynn effect?

 

Changes in mean IQ between 1909 and 2013 (Pietschnig and Voracek 2015, p. 285)

 

 

Because of the Flynn effect, average IQ has risen by 35 points over the past century. That’s more than the difference between the threshold of mental retardation and the current average. Does that seem plausible?

 

In a 1984 paper, James Flynn showed that the mean IQ of White Americans rose by 13.8 points between 1932 and 1978 (Flynn 1984). When that increase, now called the Flynn effect, was charted between 1920 and 2013, the gain in IQ was found to be no less than 35 points (Pietschnig and Voracek 2015).

 

The IQ gain did not happen at a uniform rate. It can be broken down into five stages:

 

·         a small increase between 1909 and 1919 (0.80 points/decade)

·         a surge during the 1920s and early 1930s (7.2 points/decade)

·         a slower pace of growth between 1935 and 1947 (2.1 points/decade)

·         a faster one between 1948 and 1976 (3.0 points/decade)

·         a slower pace thereafter (2.3 points/decade)

 

The Flynn effect began in the core of the Western world and is now ending there. In fact, it has ended altogether in Norway and Sweden and has begun to reverse itself in Denmark and Finland (Pietschnig and Voracek 2015, pp. 283, 288-289).

 

Was it a real increase?

 

Average IQ has thus risen by 35 points over the past century. That’s more than the difference between the threshold of mental retardation and the current average. Does that seem plausible?

 

My mother went to high school during the 1930s, and I went during the 1970s. So my generation should be 13.8 points smarter than hers. That’s a big difference, and it should have been obvious to someone like myself who knew people from both generations.

 

It wasn’t obvious. My mother had a small library of books that she often consulted, mostly religious literature and works like Welcome Wilderness and Little Dorrit. Not all of her generation were obsessive readers, but many were. And the books they read weren’t light reading. Fiction typically had complex plots with subplots running alongside each other, and religious books were a maze of Biblical references that would seem obscure unless you knew the Bible, usually the King James Version. If you could handle that, you could handle string theory.

 

The Flynn effect also implies that post-millennials are 10 points smarter than my generation. Again, that’s not my impression. Books and movies now have simpler plots and use a smaller vocabulary—a key component of verbal intelligence. According to the General Social Survey, vocabulary test scores fell by 7.2% between the mid-1970s and the 2010s among non-Hispanic White Americans. The decline affected all levels of educational attainment, so it wasn’t just a matter of dumber people now going to college (Frost 2019; Twenge et al. 2019). The same period also saw an increase in reaction time: since the 1970s, successive birth cohorts have required more time, on average, to process the same information (Madison 2014; Madison et al. 2016). 

 

Finally, there is the genetic evidence, specifically alleles associated with high educational attainment. In Iceland, those alleles have become steadily fewer in cohorts born since 1910 (Kong et al. 2017). The same trend has been observed between the 1931 and 1953 birth cohorts of European Americans (Beauchamp 2016). According to the Icelandic study, the downward trend is happening partly because more intelligent Icelanders are staying in school longer and postponing reproduction. But it is also happening among those who do not pursue higher education. Modern culture seems to be telling people that children are costly and bothersome, and that message is most convincing to people who like to plan ahead.

 

Some writers have argued that the genetic decline in intellectual potential has been more than offset by improvements to our learning environment, particularly better and longer education. This improved environment is helping us do more with our intellectual potential. But is there real-world evidence that we are, on average, becoming smarter? Robert Howard (1999, 2001, 2005) cites four lines of evidence:

 

·        The prevalence of mild mental retardation has fallen in the US population and elsewhere.

·        Chess players are reaching top performance at earlier ages.

·        More journal articles and patents are coming out each year.

·        According to high school teachers who have taught for over 20 years, “most reported perceiving that average general intelligence, ability to do school work, and literacy skills of school children had not risen since 1979 but most believed that children's practical ability had increased” (Howard 2001).

 

The above evidence is debatable, as Howard himself acknowledges. Fewer children are being diagnosed as mental retarded because that term has become stigmatized. Prenatal screening has also had an impact. As for chess, it’s a niche activity that tells us little about the general population. More journal articles are indeed being published each year, but the reason has more to do with pressure to “publish or perish.” Finally, teachers are not objective observers: they are part of a system that rewards certain views and penalizes others. And if they reject that system, they probably won’t stick around for more than twenty years.

 

A last word

 

I suspect we’re getting better at some cognitive tasks, particularly the ones we learn at school—if only because we’re spending more of our lifetime in the classroom. One of those tasks is sitting down at a desk and taking a test. We’re better not only at that specific task but also at the broader one of thinking in terms of questions and answers. Previously, we just learned the rules and imitated those who knew better than us.

 

Test-taking certainly made an impression on my mental development. Long after my undergrad studies I would have nightmares of sitting alone in an immense exam hall and not knowing the answer to an insoluble question.

 

References

 

Beauchamp, J.P. (2016). Genetic evidence for natural selection in humans in the contemporary United States. Proceedings of the National Academy of Sciences. 113(28): 7774-7779. https://doi.org/10.1073/pnas.1600398113  

 

Flynn, J.R. (1984). The mean IQ of Americans: Massive gains 1932–1978. Psychological Bulletin 95(1):29–51. https://psycnet.apa.org/doi/10.1037/0033-2909.95.1.29   

 

Frost, P. (2019). Why is vocabulary shrinking? Evo and Proud, September 11. https://evoandproud.blogspot.com/2019/09/why-is-vocabulary-shrinking.html

 

Frost, P. (2020). From here it’s all downhill. Evo and Proud, March 16. https://evoandproud.blogspot.com/2020/03/from-here-its-all-downhill.html

 

Howard, R. W. (1999). Preliminary real-world evidence that average human intelligence really is rising. Intelligence 27: 235–250. https://doi.org/10.1016/S0160-2896(99)00018-5  

 

Howard, R. W. (2001). Searching the real world for signs of rising population intelligence. Personality and Individual Differences 30: 1039–1058. https://doi.org/10.1016/S0191-8869(00)00095-7

 

Howard, R. W. (2005). Objective evidence of rising population ability: A detailed examination of longitudinal chess data. Personality and Individual Differences, 38(2), 347–363. https://doi.org/10.1016/j.paid.2004.04.013

 

Kong, A., M.L. Frigge, G. Thorleifsson, H. Stefansson, A.I. Young, F. Zink, G.A. Jonsdottir, A. Okbay, P. Sulem, G. Masson, D.F. Gudbjartsson, A. Helgason, G. Bjornsdottir, U. Thorsteinsdottir, and K. Stefansson. (2017). Selection against variants in the genome associated with educational attainment. Proceedings of the National Academy of Sciences 114(5): E727-E732.  https://doi.org/10.1073/pnas.1612113114

 

Madison, G. (2014). Increasing simple reaction times demonstrate decreasing genetic intelligence in Scotland and Sweden, London Conference on Intelligence. Psychological comments, April 25 #LCI14 Conference proceedings. http://www.unz.com/jthompson/lci14-questions-on-intelligence/    

 

Madison, G., M.A. Woodley of Menie, and J. Sänger. (2016). Secular Slowing of Auditory Simple Reaction Time in Sweden (1959-1985). Frontiers in Human Neuroscience, August 18. https://doi.org/10.3389/fnhum.2016.00407

 

Pietschnig, J., and M. Voracek. (2015). One Century of Global IQ Gains: A Formal Meta-Analysis of the Flynn Effect (1909-2013). Perspectives on Psychological Science 10(3): 282-306. https://doi.org/10.1177/1745691615577701

 

Twenge, J.M., W.K. Campbell, and R.A. Sherman. (2019). Declines in vocabulary among American adults within levels of educational attainment, 1974-2016. Intelligence 76: 101377. https://doi.org/10.1016/j.intell.2019.101377

From here it's all downhill

Polish IQ scores for three subtests: Similarities, Vocabulary, and Arithmetic (Wikicommons - Pedros)

Throughout the West the Flynn effect is coming to an end. More and more people are bumping up against a ceiling that is getting lower and lower.



The Flynn effect is ending throughout the West. After a century of steady increase, average IQ scores are levelling off and even starting to fall in Scandinavia, England, and Austria (Dutton 2016; Flynn 2007, p. 143; Rindermann 2018, pp. 85-88; Teasdale and Owen 2005). 

But how real was that increase anyway? Read the popular literature from a hundred years ago. Look at the size of the vocabulary and the complexity of the plots. Also look at what people had to know when graduating from elementary school. IQ scores increased during the 20th century largely because people became more familiar with taking standardized tests and thinking in terms of standardized answers to standardized questions. They had no choice. This was a time when people were staying increasingly longer in school. As higher education became the rule for everyone—first high school and then college and university—good grades became the goal for everyone, and not just for a small elite. 

So the average phenotype has been pushed to the limit by compulsory secondary education and by social pressure to pursue tertiary education. Meanwhile, the average genotype has been trending in another direction. 

- Reaction time has lengthened, i.e., people are taking longer on average to process the same information. In Great Britain, mean reaction time has risen by 13 points since the Victorian era (Woodley et al. 2013). This finding may be due to better sampling of the general population over time (hbd*chick 2013); however, a Swedish study found the same lengthening of reaction time, particularly in cohorts born since the 1970s (Madison 2014; Madison et al. 2016). 

- The genetic basis for intelligence has declined, as shown by a progressive decline in the "polygenic score" of alleles associated with educational attainment. In Iceland, this score has fallen since the cohort born in 1910 (Kong et al. 2017). Among Euro Americans, it fell between the 1931 and 1953 birth cohorts (Beauchamp 2016).

In sum, the average phenotype and the average genotype have been moving in opposite directions. This point is made by Hong (2020):

In general, more educated women delay the onset of childbearing and have fewer children overall compared to less educated women. This pattern is very robust in both developed and developing countries, and various theories have been proposed to explicate the intrinsic, potentially causal relationship between education level and fertility.

[...] The phenotype of EA [educational attainment], on the other hand, may experience a very different type of selective pressure. A large literature in sociology shows that educational attainment and socio-economic status are associated, and cultural evolutionary theory predicts that humans readily copy the behaviors of those who are perceived as more prestigious or successful. Although educational attainment cannot be "copied" in a literal sense, individuals who pick models with high EA are likely to be more motivated in learning and committed to their academic studies, and as a result become more likely to obtain higher EA themselves. Thus, genetic fitness and cultural fitness of the same trait (EA) invites selection in opposite directions [...].

As long as the genetic decline is offset by better and longer education, there is nothing to worry about. We may be learning more slowly, but we're spending more time learning. As Courtiol et al. (2016) argue: "the jockey has become more skilled as the power of the horse dwindles."


What if the horse collapses?

Unfortunately, this situation cannot go on forever. The phenotype (“jockey”) and the genotype (“horse”) are not independent entities; in fact, the former is developed within the limits of the latter. As the upper limit gets lower and lower, more and more of us will be bumping up against that ceiling. In other words, "at some point genetics will become the limiting factor in determining the phenotype of EA, which may eventually decline as a result of natural selection" (Hong 2020).

That point seems to be ... about now. In the West, the Flynn effect has exhausted itself, having used up the wiggle room of education. From here it's all downhill.  As Dutton et al. (2016) note in their review of the literature:

Eventually, the ceiling of this ability would be reached and the losses would start to reveal themselves on IQ tests. In addition, Woodley and Fernandes (2016) have shown that the Flynn Effect is not primarily occurring on general and heritable intelligence factor g, whereas the negative Flynn Effect does seem to occur on g. The negative Flynn Effect displays a Jensen Effect, and is mainly occurring on the more heritable abilities.

References

Beauchamp, J.P. (2016). Genetic evidence for natural selection in humans in the contemporary United States. Proceedings of the National Academy of Sciences. 113(28): 7774-7779.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948342/

Courtiol, A., F.C. Tropf, and M.C. Mills. (2016). When genes and environment disagree: Making sense of trends in recent human evolution. Proceedings of the National Academy of Sciences 113(28): 7693-7695.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948334/

Dutton, E., D. van der Linden, and R. Lynn. (2016). The negative Flynn Effect: A systematic literature review. Intelligence 59: 163-169.
https://www.gwern.net/docs/iq/2016-dutton.pdf

Flynn, J.R. (2007). What is Intelligence? Beyond the Flynn Effect. Cambridge University Press.
https://books.google.ca/books?id=qvBipuypYUkC&printsec=frontcover&hl=fr&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

Hbd*chick (2013). A response to a response to two critical commentaries on woodley, te nijenhuis and murphy. May 27
http://hbdchick.wordpress.com/2013/05/27/a-response-to-a-response-to-two-critical-commentaries-on-woodley-te-nijenhuis-murphy-2013/

Hong, Z. (2020). Modelling the on-going natural selection of educational attainment in contemporary societies. Journal of Theoretical Biology 493: 110210
https://www.biorxiv.org/content/10.1101/605311v2.full

Kong, A., M.L. Frigge, G. Thorleifsson, H. Stefansson, A.I. Young, F. Zink, G.A. Jonsdottir, A. Okbay, P. Sulem, G. Masson, D.F. Gudbjartsson, A. Helgason, G. Bjornsdottir, U. Thorsteinsdottir, and K. Stefansson. (2017). Selection against variants in the genome associated with educational attainment. Proceedings of the National Academy of Sciences 114(5): E727-E732.

https://core.ac.uk/download/pdf/154416179.pdf

Madison, G. (2014). Increasing simple reaction times demonstrate decreasing genetic intelligence in Scotland and Sweden, London Conference on Intelligence. Psychological comments, April 25
#LCI14 Conference proceedings
http://www.unz.com/jthompson/lci14-questions-on-intelligence/   

Madison, G., M.A. Woodley of Menie, and J. Sänger. (2016). Secular Slowing of Auditory Simple Reaction Time in Sweden (1959-1985). Frontiers in Human Neuroscience, August 18
https://www.frontiersin.org/articles/10.3389/fnhum.2016.00407/full  

Rindermann, H. (2018). Cognitive Capitalism. Human Capital and the Wellbeing of Nations. Cambridge University Press.

Teasdale, T.W., and D.R. Owen. (2005). A long-term rise and recent decline in intelligence test performance: The Flynn Effect in reverse. Personality and Individual Differences 39(4): 837-843.
https://doi.org/10.1016/j.paid.2005.01.029   

Woodley of Menie, M.A., and H.B.F. Fernandes. (2016). Showing their true colours: Possible secular declines and a Jensen effect on colour acuity — More evidence for the weaker variant of Spearman's Other Hypothesis. Personality and Individual Differences 88: 280-284.
https://www.sciencedirect.com/science/article/abs/pii/S0191886915005826

Woodley, M.A., J. Nijenhuis, and R. Murphy. (2013). Were the Victorians cleverer than us? The decline in general intelligence estimated from a meta-analysis of the slowing of simple reaction time. Intelligence 41: 843-850. 
https://pdfs.semanticscholar.org/e8cc/634169c7c5d3e4738fe08091c86177be1380.pdf

Rise of the West, part II

Paysage à Saint-Joachim (1903), Clarence Gagnon. A hundred years ago genetic evolution came to a halt throughout the West, yet cultural evolution continued to forge ahead ... at an accelerating speed.

My last post covered the reasons why liberal regimes have historically prevailed over conservative ones. In short, liberalism delivers the goods. By reducing the importance of kinship, it has given the market a freer rein to mobilize labor and capital for production of goods and services. More wealth is created—not only in peacetime but also, and just as critically, in wartime. Because liberal regimes are not tied to a single ethnocultural community, they can recruit from a broader pool of people and, if need be, relocate production of arms and ammunition to territories far from enemy attack.

In this post I wish to discuss the contradictions of liberalism. By "contradiction" I mean an inherent problem that will worsen even in the absence of organized opposition. Here, I will focus on one problem: liberal regimes tend to erode their own cultural and genetic foundations, thus undermining the cause of their success.

End and reversal of gene-culture coevolution

Liberalism emerged in northwest Europe. This was where conditions were most conducive to dissolving the bonds of kinship and creating communities of atomized individuals who produce and consume for a market. Northwest Europeans were most likely to embark on this evolutionary trajectory because of their tendency toward late marriage, their high proportion of adults who live alone, their weaker kinship ties and, conversely, their greater individualism. This is the Western European Marriage Pattern, and it seems to go far back in time. The market economy began to take shape at a later date, possibly with the expansion of North Sea trade during early medieval times and certainly with the take-off of the North Sea trading area in the mid-1300s (Note 1).

Thus began a process of gene-culture coevolution:  people pushed the limits of their phenotype to exploit the possibilities of the market economy; selection then brought the mean genotype into line with the new phenotype. The cycle then continued anew, with the mean phenotype always one step ahead of the mean genotype.

This gene-culture coevolution has interested several researchers. Gregory Clark has linked the demographic expansion of the English middle class to specific behavioral changes in the English population: increasing future time orientation; greater acceptance of the State monopoly on violence and consequently less willingness to use violence to settle personal disputes; and, more generally, a shift toward bourgeois values of thrift, reserve, self-control, and foresight. Heiner Rindermann has presented the evidence for a steady rise in mean IQ in Western Europe during the late medieval and early modern era. Henry Harpending and myself have investigated genetic pacification during the same timeframe in English society. Finally, hbd*chick has written about individualism in relation to the Western European Marriage Pattern (Note 2).

This process of gene-culture coevolution came to a halt in the late 19th century. Cottage industries gave way to large firms that invested in housing and other services for their workers, and this corporate paternalism eventually became the model for the welfare state, first in Germany and then elsewhere in the West. Working people could now settle down and have families, whereas previously they had largely been a lumpenproletariat of single men and women. Meanwhile, middle-class fertility began to decline, partly because of the rising cost of maintaining a middle-class lifestyle and partly because of sociocultural changes (increasing acceptance and availability of contraception, feminism, etc.).

This reversal of class differences in fertility seems to have reversed the gene-culture coevolution of the late medieval and early modern era. The evidence is still incomplete, but a consistent pattern is emerging:

1. Mean reaction time has risen in Great Britain by 13 points since Victorian times (Woodley et al. 2013). This finding may be an artefact of better sampling of the general population over time (hbd*chick 2013a). A Swedish study, however, has confirmed this lengthening of reaction time, particularly in cohorts born since the 1970s (Madison 2014; Madison et al. 2016).

2. The genetic basis of intelligence has fallen in Iceland since the cohort born in 1910. This is shown by a progressive decrease in the "polygenic score" of alleles associated with high educational attainment (Kong et al. 2017).

3. The Flynn effect is slowing throughout the West (Flynn 2007, p. 143). In Scandinavia, mean IQ peaked during the late 1990s and has since declined (Teasdale and Owen 2005). A review of this literature has shown recent declines in mean IQ in England, Denmark, Finland, and Austria and a leveling off in Norway and Australia (Rindermann 2018). The Flynn effect does not, in itself, seem to be a real increase in intelligence. Rather, it is simply a greater familiarity by people with the process of doing tests and, as such, has masked an underlying decline in real intelligence. Now that the Flynn effect has exhausted itself, we are seeing this underlying decline.

Causes?

Some of this decline may be due to class differences in fertility, especially during the early to mid-20th century. Today, with widespread use of contraception and abortion by all social classes, this factor is much less operational (Jayman 2012). Recently, two economists, Bernt Bratsberg and Ole Rogeberg, have found that the reversal of the Flynn effect in Norway is largely explained by "within-family variation." So this decline is not due to the poor outbreeding the rich or to immigrants outbreeding natives. 

It doesn't follow, however, as Bratsberg and Rogeberg argue, that a genetic cause is excluded. In Norway, as elsewhere, siblings are increasingly half-siblings. This is not a minor factor. Bratsberg and Rogeberg charted their country's IQ decline by looking at pairs of brothers; their data came from the military conscript register, and only men are subject to conscription. To produce a pair of brothers, a woman has to have three children on average. Among Norwegian women with three children, 36.2% have had them by two or more men (Thomson et al. 2014). Furthermore, because half-siblings tend to be born farther apart than full-siblings, they have contributed more to changes in mean IQ over time. 

If the genetic basis of intelligence has been declining between older and younger half-siblings, two things must be happening:

- Divorced mothers are, on average, having their second children by lower-IQ men;

- Such men have been contributing more than other men to succeeding generations of Norwegians, at least during the last forty years.

Lappegård et al. (2011) found that multi-partner fatherhood is most common among Norwegian men with the lowest level of education. Furthermore, multi-partner fertility has increased over time among such men. Thomson et al. (2014) have similarly observed that education is negatively associated with childbearing across partnerships in Australia, United States, Norway, and Sweden. These differentials increased from the 1970s to the 2000s.

Unfortunately, we cannot easily measure the impact of multi-partner fatherhood on the IQ of the next generation. How can we compare the first father’s children with the second father’s children when Norwegian statistics do not identify a child's biological father? Only the "registered father" is identified. Once a man has adopted the earlier children of his spouse, he becomes their father for all statistical purposes.

Uncoupling of gene-culture coevolution

There has thus been an uncoupling of gene-culture co-evolution. Genetic evolution is leveling off throughout the West and even reversing in some countries. Meanwhile, cultural evolution has been forging ahead. The mean phenotype is no longer one step ahead of the mean genotype. It's several steps ahead.

A century ago the market economy was important, but a lot of economic activity still took place within the family, especially in rural areas. In the late 1980s I interviewed elderly French Canadians in a small rural community, and I was struck by how little the market economy mattered in their youth. At that time none of them had bank accounts. Few even had wallets. Coins and bills were kept at home in a small wooden box for special occasions, like the yearly trip to Quebec City. The rest of the time these people grew their own food and made their own clothes and furniture. Farms did produce food for local markets, but this surplus was of secondary importance and could just as often be bartered with neighbors or donated to the priest. Farm families were also large and typically brought together many people from three or four generations. 

By the 1980s things had changed considerably. Many of my interviewees were living in circumstances of extreme social isolation, with only occasional visits from family or friends. Even among middle-aged members of the community there were many who lived alone, either because of divorce or because of relationships that had never gone anywhere. This is a major cultural change, and it has occurred in the absence of any underlying changes to the way people think and feel.

Whenever I raise this point I'm usually told we're nonetheless better off today, not only materially but also in terms of enjoying varied and more interesting lives. That argument made sense back in the 1980s—in the wake of a long economic boom that had doubled incomes, increased life expectancy, and improved our lives through labor-saving devices, new forms of home entertainment, and stimulating interactions with a broader range of people.

Today, that argument seems less convincing. Median income has stagnated since the 1970s and may even be decreasing if we adjust for monetization of activities, like child care, that were previously nonmonetized. Life expectancy too has leveled off and is now declining in the U.S. because of rising suicide rates among people who live alone. Finally, cultural diversity is having the perverse effect of reducing intellectual diversity. More and more topics are considered off-limits in public discourse and, increasingly, in private conversation. 

Liberalism is no longer delivering the goods—not only material goods but also the goods of long-term relationships and rewarding social interaction.

To be cont'd

Notes

1. Markets, of course, go much farther back in time, farther than the earliest historical records. For most of that time, however, they were secondary to kinship. People organized their lives primarily in terms of blood ties or the ties of procreation between husband and wife. The main unit of economic activity was the family. Markets were not only of secondary importance but also highly localized in space and time. In short, there were markets but no market economy.

2. Hbd*chick has accused me of plagiarizing her work on the Hajnal Line and the Western European Marriage Pattern. The truth is that I became interested in that subject much earlier— during the early 1990s in an exchange of letters with Kevin MacDonald in the pages of Ethology and Sociobiology. Afterwards, I intended to write a follow-up that would prove two points: 1) the Western European Marriage Pattern predates Christianity; and 2) this cultural environment has selected for certain psychological traits. Over the years I gathered material, but I didn't feel I had enough for a publishable article. I finally wrote up several blog posts on the subject in 2011 and eventually a full article in 2017. Meanwhile, hbd*chick had published her first post on the Hajnal Line in 2011. I did read that post but she seemed to be taking the same position that Kevin MacDonald had taken, i.e., that the WEMP was created by the Catholic Church and that outbreeding was key to emergence of the Western mindset. Later, in a 2012 post, she began to see the WEMP as a template for gene-culture coevolution. At that point I had the impression she was drawing on my material, either directly from my articles and blog posts or indirectly through various bloggers.

So did I "discover" this idea? No, of course not. Neither I nor hbd*chick was the first to write about the Hajnal Line or the WEMP. More importantly, neither of us was the first to link the WEMP to Western European individualism and mercantilism. I would award that title to Wally Seccombe in his 1992 book A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe. In the end, few ideas are truly original. It's no coincidence that both of us began writing about that subject around the same time. Other people were writing on related topics, and those people were influencing both me and her. I'm thinking here about authors like Gregory Clark and blogs like Jayman and Those Who Can See. I didn't read it at the time, but in January 2011 Kevin MacDonald wrote a book review that discussed the Hajnal Line and European individualism:

The nuclear family, freed from extended kinship obligations, is the basis of Western social organization. It is unique relative to other culture areas. This pattern is particularly noticeable in the Northwest of Europe rather than the Pontic steppe region. As one goes from the Northwest of Europe to the Southeast, there is an increase in joint family structure, with brothers living together with parents, grandparents and children. Family historian John Hajnal discovered the "Hajnal line" that separates Western Europe from Eastern Europe, the former characterized by nuclear family structure, relatively late marriage and large numbers of unmarried in economically difficult times, the latter by joint family structure and relatively early and universal marriage.

Finally, while preparing my 2017 article, I wanted to cite hbd*chick as someone with an alternate point of view, but I couldn't find anything published under her real name. There were only pseudonymous posts from her blog. To cite her in my manuscript would require inserting citations like (hbd*chick 2014). The reviewers would immediately notice, and the chances of rejection would increase accordingly. This point should be obvious.

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