The IQ debate: Total vs. Per-capita IQ

There is a common misconception about IQ as it pertains to national IQ and the purported ‘dumbing down of society’. Commentators online frequently lament about the existence of such dumbing-down. The misconception has to do with confusing or conflating relative or per-capita intelligence for absolute/total intelligence of a nation. These are related yet distinct enough that the ramifications of these differences are significant.

Consider some countries:

Country A: 300 million people, 10 million smart people

Country B: 80 million people 1 million smart people

Country C: 1 billion people 15 millions smart people

Country D: 10 million people 2 million smart people

By ‘smart’ , I am assuming an IQ above 120 or so, but the threshold is not so important as long as the distinction between smart and average is obvious enough to matter economically and socially.

If one goes by proportion or per-capita IQ, then country D (which is supposed to represent a Nordic country or Singapore or South Korea) is the smartest country by a long shot. But in terms of intellectual output, A and C (which represents China) would beat D, as there are more total smart people. Even though country A, which is supposed to represent the US, has a smaller ratio of smart people compared to D, there are more total smart people , so the intellectual output should be higher, especially if the economic and social conditions exist for such smart people to reach their full cognitive potential.

Adding a bunch of dull people to a population that already has a a lot of smart people does not lower intellectual output ( assuming assortative mating selecting for the phenotype of intelligence , as smart people tend to marry other smart people) but it does lower mean IQ. From Nature.com Genetics and intelligence differences: five special findings, “Assortative mating is far greater for intelligence than for most other traits. For example, assortative mating is about 0.20 for height68 and for weight,69 and about 0.10 for personality. For intelligence, assortative mating is about 0.40.”

One must also keep in mind that even average or even below-average-IQ couples can still produce high-IQ children, owing to genotypic variance, who will likely join the ‘smart fraction’ and find a partner of similar intelligence. So even if high-IQ people have a sub-replacement fertility rate, the introduction of new smart people into the ‘smart faction’ from the much larger pool of less intelligent people, may be enough to offset this. Variance due to mutations is why evolution exists at all, and cannot be ignored. Parents’ IQ plays a role in offspring IQ, but so does various mutations in utero.

Having total national intellectual output rise as mean national IQs gradually fall, is paradoxical and counterintuitive, but that seems to be the case as far the the US is concerned, provided that the rate of brain drain due to dysgenic mating doesn’t exceed the contributions to IQ due to eugenic mating and new entrants to the ‘smart faction’ due to mutations and or immigration.

America’s large ‘smart fraction’ combined with optimal economic social conditions (such as free market capitalism, a culture of entrepreneurship that rewards and exalts hard work, the ‘ownership society,’ an abundance of venture capital, and prestigious research intuitions such as Harvard, MIT, Stanford, Cornell, etc.) explains why Silicon Valley and the US economy is so dominant and successful, especially since 2008, as the rest of the world stagnates, even in spite of large populations of below-average-scoring groups such as Blacks and Hispanics. These dullards may drag down median and mean national IQ, but national intellectual output does not fall. This also explains why Covid’s long-term impact on the US economy was shallow and limited in spite of all the media doom and gloom and a lot of deaths’ and sickness , because the smart people in Silicon Valley and Seattle, in the tech and finance sectors especially, were largely immune, whereas it was mostly average/low-IQ individuals and businesses that got sick or closed. This is a subtle distinction that people ignore or get confused by.

Country B represents Brazil, Chile, Turkey, or one of many low/below-average-IQ countries. This explains why emerging markets have lagged the US considerably since 2008 in terms or real, dollar-adjusted GDP growth and stock market gains, owing to a lack of smart people and also a lot of corruption and a culture that does not reward industriousness and competence (it is called the Protestant work ethic, not the Catholic work ethic or the Muslim work ethic). In spite of embracing neoliberal free market capitalism over the past 40 or so years, such countries still cannot succeed as well as ‘red China’ or the quasi-socialist Nordic countries.

What about those difficult exams from the 19th and early 20th century that elementary and secondary students were required to take? Doesn’t this prove there is dumbing-down given that even many American adults are unable to answer all of those questions, let alone high school graduates? There are a few things to keep in mind: graduation rates were considerably lower 100 years ago than today. High school 100+ years ago was the equivalent of probably graduate school today, and only a small percentage of students would be expecte to answer all those questions correctly (it is not like 100 years ago all 8th graders were better-educated than today’s 8th graders; some were, but likely many weren’t). Getting all those questions correct would be like the modern equivalent of a near-perfect SAT score. Second, such exams test typically test general knowledge, but the trend in recent years is specialized knowledge (such as high school students taking AP math and or learning coding). 100 years ago, likely very few high school students learned calculus, but nowadays it is fairly common for high school seniors to learn at least single-variable calculus.

Now in terms of what country is nicest to live in terms of minimal unrest and least resembles an ‘idiocracy’, the answer is D, as it has the highest ratio of smart people.