https://amgreatness.com/2025/03/12/immigration-and-fertility-by-nation/
“But one thing is certain: the human population is rapidly declining in every developed nation on earth. How we adapt to that, and who we invite into our nations, should involve a discussion that includes all variables.”
When a nation’s population grows, it’s easier for that nation to experience economic growth. This is the conventional economic wisdom that has been unchallenged for centuries. And there was little reason to challenge this axiom, because throughout human history, the global population trend has been one of perpetual increase. But as birthrates are crashing in wealthier nations, without exception, it may be time to reexamine what constitutes healthy economic growth and how it may be achieved without increasing population.
The way Western nations have chosen to respond to crashing birthrates is to rely on mass immigration. Tens of millions of people are being encouraged to migrate from poor nations where fertility remains high into rich nations with low fertility. This gives rise to challenges that remain unresolved and indeed may worsen as people arrive by the millions from cultures with dramatically different values and beliefs than the host culture.
Let’s assume for a moment that these cultural clashes can be resolved. That’s making a huge leap of faith, but let’s envision a world where, as the developed nations saw their indigenous population diminish, they were steadily replaced by immigrants from high-fertility nations. This is not mere speculation. Based on current trends, within a generation, indigenous populations in developed nations will become minorities, outnumbered by immigrants.
So notwithstanding how these nations would maintain social stability in the face of replacement levels of immigration, and notwithstanding how the indigenous cultures would merge with the immigrant cultures into something unrecognizable by any historical comparisons, what else can we surmise might characterize these new and blended populations?
One of the most salient determinants of individual success is an individual’s general intelligence, and what’s true for individuals is also true for nations. The data on average IQ by nation is available online, and when checking multiple sources here, here, and here, the overall figures were remarkably consistent. What is also true, although the scatter plot does reveal some outliers, is that in the world today, the higher the national average IQ, the lower the fertility. The converse is also true.