The N. vs S. Korean example you mention is explicitly discussed in one of Hsu&#x27;s articles. (Secular change in height due to improved environmental conditions.)<p><a href="http:&#x2F;&#x2F;arxiv.org&#x2F;abs&#x2F;1408.3421" rel="nofollow">http:&#x2F;&#x2F;arxiv.org&#x2F;abs&#x2F;1408.3421</a><p>Section 2.3:<p>&quot;Let me reiterate that within a range of favorable environments (i.e., providing good nutrition, hygiene, and access to education), evidence strongly supports the claim that individual differences in cognitive ability are largely associated with genetic differences.<p>Figure 8. Increase in stature in European countries over time, almost +2 SD. Nutrition, hygiene, and average number of years of schooling all improved dramatically over the last 100 years, leading to improvements in both physical and mental development.&quot;<p>You should probably read his paper carefully before making ad hominem attacks. Save your SJW signaling.