[Adverblessly]

I can't speak to other countries, but here in Israel at least, religion is highly correlated with number of children.

Focusing on jewish women, fertility rates for different levels of religion in 2021-2023:

  Ultra-orthodox                6.48
  Religious                     3.74
  Traditional-religious         2.81
  Traditional, not so religious 2.20
  Not religious, secular        1.96

So naturally over time the religious portion of the population grows.

[Thorrez]

What's the difference between "Religious" and "Traditional-religious"?

Is "Traditional-religious" a strict subset of "Religious"? Is Ultra-orthodox a strict subset of "Traditional-religious"? If so, it's odd that Traditional-religious has lower fertility than Religious.

[somenameforme]

And this follows globally - fertility is one of the most interesting and critical issues of our time. It's going to change the future in ways most absolutely do not appreciate. On this topic most people see the world as inevitably becoming more secular because that's how society has trended during most of our lives, so it seems almost like a natural law. Yet even fertility alone means that society will almost certainly become substantially less secular over time.

This also has implications for the long-term population of Earth. The claim we'll reach a "max" population sometime this century is quite silly. It'll be a local max, not a global max. Because if even a single group maintains a positive fertility rate, that group will eventually drive the population to start increasing again (and basically take ownership of the gene pool while they're at it).

[mathgeek]

> It'll be a local max, not a global max.

There really isn’t any way to know this for a fact. The future could hold technology that allows us to expand far beyond the current population, but it also could lead to setbacks that the population never recovers from. It is reasonable to guess it’s a local max.

[somenameforme]

I think this argument would make more sense if it were external constraints that were driving a declining population. But the population is only decreasing because the majority group of people stopped having children. So they will remove themselves from the gene pool, the minority will become the majority, and away we'll go again.

As an interesting factoid the Roman Empire, which for many people of the time would have had some analogs to 'the world', also had a fertility collapse prior to its end, that they tried to combat with quite strict laws, but ones which were ultimately ineffectual. Of course that was hardly the end of the story!