Too smart to breed? - The Road to Idiocracy

It is well known that there is a negative correlation between IQ and fertility. This is the entire premise of the movie Idiocracy. Empirical evidence shows lower IQ people have more children and have them sooner while higher IQ people do the opposite. 

Countries in South America, the Middle East, and Africa are often cited as having low average IQs, and their populations are either stable or growing. In contrast, almost every high IQ country is experiencing population decline.

Attaining a middle-class standard of living in an industrialized country today requires either delaying or forgoing parenthood. The main reason, at least in the US, is that while salaries have increased even when adjusting for inflation, the cost of home ownership has more than quadrupled since 1950. 

No amount of tax cuts or other incentives will spur family formation in rich countries until more cheap housing is built. 

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But even accounting for the lower household income in 1950, the relative purchasing power was greater at the onset of the ’50s than it is today. For instance, it took about 2.5 years’ worth of paychecks for a person earning the average salary for white workers in 1950 to afford a new home, while the median cost of a new home today is nearly six times the average salary. 

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What My Life Would Have Cost in 1950 - History Facts

In contrast, housing is much cheaper in poorer countries, and so it is much easier to start a family. 

A system that discourages reproduction is a few generations from collapse. In this, perhaps the poorer countries of the world are being smarter in the long run. 

There are cultural factors as well which put North America, Europe, and East Asia at a disadvantage. Customs such as arranged marriages and bride price are frowned upon in more feminist societies, yet these same practices also ensure that the maximum number of young people find partners. 

Another more basic problem is that women generally will not marry or have children with men poorer than they are. In countries where women have mostly the same education and career opportunities as men, this means high-earning women price themselves out of the marriage market. If women spend their younger years getting and education and building a career, they end up as less attractive to high-earning men while at the same time being unattracted to low-earning men. 

Population decline in North America, Europe, and East Asia is inevitable until economic and cultural conditions change.