Writing* at the Wall Street Journal, author Louise Perry looks at falling birth rates worldwide, relates them to political orientations, and ends up with more questions than answers. One conclusion she does reach is this.
Twin studies suggest that political attitudes are roughly 40% heritable. Of course, children do sometimes diverge from or react against their parents’ politics. But in general, expect the partisan fertility gap to usher in a U.S. that is more conservative. In fact, the whole of the developed world is on track to become more conservative.
In brief, wherever found, conservatives are having more children than progressives.
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I'm going to suggest a possibly related factor. The sexually conventional have more kids than those whose sexuality is unconventional.
The sexually unconventional have tended to be progressive for absolutely rational reasons. Declining repression of unconventional sexuality throughout the developed world has paralleled declining birth rates. I believe this parallel may not be a coincidence.
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*Article is behind a "semi-paywall." You can scroll it on the top half of the screen while your screen's bottom half is filled with a pitch to sell you a WSJ subscription.
