“Inheritance facts” (Heritability)


There is a minor Internet presence who calls himself the Libertarian Realist, though given his endorsement of the Confederacy and fluoridation conspiracy theories, I doubt he’s either.

And as a long-time libertarian and skeptic, I find libertarian conspiracy theorists to be the planet’s most baffling creatures. They think a government too incompetent to build roads, run schools, or implement a sensible welfare program will simultaneously master geoengineering, the AIDS crisis, and false flag shootings.

With this guy, however, conspiracy theories are only a tiny fraction of his work. He focuses mostly on race and fixates on the idea that those of his color (excluding Jews) are more intelligent and fit than all other skin tones, especially blacks.

He arrived at these conclusions mostly by misunderstanding, or choosing to ignore, how heritability works. Eminent skeptic Emil Karlsson explained that heritability estimates the amount of variation in a given trait within a population that cannot be explained by environment or random chance. Further, it is unrelated to genetic differences between populations, much as the Libertarian Realist wishes that it were.

Science blogger Gerhard Adam provided a concise description when he wrote,  “Heritability addresses the relationship between nature (genetics) and nurture (environment), so that as each changes, the variation between individuals within a population can be estimated based on these influences. In this context, environment refers to everything external to the genome that could affect expression.” 

Race pseudoscientists like the Libertarian Realist make three key errors with regard to heritability. First, they mistakenly think heritability is a measure of how genetic a trait is. They think genes are nearly the sole factor for determining traits and consider the environment much less relevant. This is mistaken since heritability is about how much variation in a trait can be explained by genetic differences.

Consider the heritability of height for North Koreans. In that country, it will mostly be determined by whether the person is in the ruling elite or is among the serfs. The vast differences in nutrition and health care between those two groups will be the primary factor. By contrast, height differences among Swedes, with their egalitarian access to healthy food and medicine, will mostly be due to genetics.

Another example. Karlsson wrote that in the mid-19th Century, U.S.-born males were 3.5 inches taller on average than Dutch men. But by 2000, Dutch males were two inches taller on average than their American counterparts. According to the Libertarian Realist’s thinking, neither population should have a height advantage since the majority in both groups were white men. But changes did occur, and the tendency of U.S. men to be taller than the Dutch and the reversal of this trend would best be explained by changes in environments for both groups.

This leads into racists’ second error, that heritability explains the differences between biological populations. But heritability refers to what proportion of variation in a trait can be explained by genetic variation within a specific population and in a specific environment. It is not a measure of how genetic a trait is. Racists rely on heritability estimates to insist that IQ and other factors are immutable, but heritability also depends on environment. And more than 90 percent of genetic variation occurs within groups and genetic diversity is seen more in clines than in socially-constructed racial categories.

Finally, racists assert that heritability renders useless any attempt to alter traits by managing environmental factors. They say any change to education, income, food, medicine, and housing will not impact the person’s traits, which they maintain are fixed at birth owing to genetics. But as Angelina Jolie’s adopted children and multiple studies can attest, persons going from destitute circumstances to affluent ones will see multitudinous benefits beyond wealth.


One thought on ““Inheritance facts” (Heritability)

  1. I’m a fan of the book “Guns, Germs, and Steel” by Richard Diamond. It explains why people in different parts of the world had an advantage throughout history due to the luck of their environment.

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