[skissane]

Last month, the US Census Bureau released their 2025 population estimates. In the ~5 years from April 1, 2020 to July 1, 2025, it estimates Kiryas Joel's population grew from 32,956 to 47,147 – a 43.1% increase. [0] That's not spectacular in the figures themselves–you'll see bigger bumps when new suburbs are established–but it is spectacular in being almost all due to natural increase instead of migration.

Evolution is still working, if we understand it as having both biological and cultural components. Give it a few centuries, and secular people will be outnumbered by ultra-Orthodox Jews, and the Amish, and radtrad Catholics, and Mormon polygamists, and so on. That's the thesis of Eric Kaufmann's 2010 book Shall the Religious Inherit the Earth? – and I believe, on the whole, he's right.

[0] https://www.census.gov/quickfacts/fact/table/kiryasjoelvilla...

[Ifkaluva]

I’ve heard this theory before. I think in the medium term it will have some effect, but a lot of these ultra religious groups have high attrition.

In the long run, evolution will have to do the job properly and actually genetically make us want more kids.

[skissane]

> but a lot of these ultra religious groups have high attrition.

Many of them actually don’t. How could Kiryas Joel be growing so fast if it did?

80-90% of children stay in the faith, and when 6 kids is considered a small family, and families with >10 kids are common - losing 10-20% in each generation doesn’t prevent exponential growth

The other factor - a constant defection rate combined with exponential growth in the underlying population produces exponential growth in absolute number of defectors - it is easy for outside observers to misread that defector boom (e.g. the “off the derech”/OTD phenomenon) as a sign the sect is in trouble

> In the long run, evolution will have to do the job properly and actually genetically make us want more kids.

Why would biological evolution “have to” if cultural evolution is doing the job for it? Of course, the two work in tandem, but the biological contribution may turn out to be an increase in frequency of alleles that make people happy in high demand sects, rather than direct desire for children