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Using education data as a proxy is interesting coming from the guy who wrote a book against education...

It doesn’t make the analysis wrong, just... interesting.

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Before the campaign to lower cholesterol started, the children of immigrants, particularly from east Asia, tended to be noticeably taller than their parents. I doubt that stunting ended at the neck.

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Nov 6, 2023·edited Nov 6, 2023

"Abundant adoption and twin studies find minimal long-run nurture effects."

The reference is to his own book. *chef's kiss*

See Sapolsky's lectures for limitations on twin studies and the difference nurture makes:

http://www.robertsapolskyrocks.com/behavioral-genetics.html

And the next lecture:

http://www.robertsapolskyrocks.com/behavioral-genetics-ii.html

An example about the sort of caution required in interpreting these studies:

<<Because heritability is a measure of variation, the fact that nearly everyone has 10 fingers to start with creates no variability in the number of fingers you have, and thus no heritability of the trait (which is 100% from your genes). However, wearing earrings in the 1950's in the US was universally common among women and verboten among men, so the heritability ends up being 100% since the one genetic factor, female or male, accounts for all of the variation.>>

Update:

As in this blog, you largely need to take Caplan at his word in his book. There is no detailed discussion of the results and I assume a lot of his conclusions are open to challenges. An example:

“A study of over 3,000 male twins from the Vietnam Era Twin Registry found almost no family influence on nicotine and alcohol dependence”

Excerpt From

Selfish Reasons to Have More Kids

Caplan, Bryan

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Here's an interesting quote:

<<As long as the adoptee’s biological parents were law abiding, their adoptive parents made little difference: 13.5 percent of adoptees with law-abiding biological and adoptive parents got convicted of something, versus 14.7 percent with law-abiding biological parents and criminal adoptive parents. If the adoptee’s biological parents were criminal, however, upbringing mattered: 20 percent of adoptees with law-breaking biological and law-abiding adoptive parents got convicted, versus 24.5 percent with law-breaking biological and adoptive parents. Criminal environments do bring out criminal tendencies. Still, as long as the biological parents were law abiding, family environment made little difference.>>

Excerpt From

Selfish Reasons to Have More Kids

Caplan, Bryan

I think it's reasonable to think that the criminal behavior (convicted or not) of Italian organized crime family members is close to 100%. So if someone says nurture doesn't matter based on these statistics, it pays to be careful about what exactly the data show.

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I currently live in Ecuador. An aspect not addressed by Bryan is that educational levels are going up in so-called third-world countries as well. Only a fraction of the people here over 50 years of age graduated from high school, but the percentage today is probably around 80%. The fraction who went to college here a generation ago is far lower than it is today. Thus, part of the increase in immigrant education is following the pattern of what is happening in their native countries. It's just that the US is a generation or two more advanced.

If you want to look at the nature vs. nurture differences, look at the difference between children who grow up in stable homes with both parents vs. those who grow up in single-parent homes vs. those who spend a considerable part of their life in foster care.

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To tie in another of Bryan's hobby horses, is anyone else alarmed at some of the ratios between "some college" and "Bachelor's degree" (aka "finished college")? If you knew nothing about a child except that their parents did not finish college (or that their immigrant parents didn't attend college), shouldn't they be steered away from college?

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