I don’t have an opinion on this either way, but this seems like an interesting observation. I would be interested to hear downvoters’ specific objections.
also didn't downvote, but clearly there are confounding variables (fertility also correlates with poverty, for example)
There is a common argument that X social group has a lot of children, thus they'll become a greater proportion of the population over time (typically applied to developing countries, immigrants etc). These arguments are flawed because humans don't really work this way, and adopt k vs r selection depending on environment.
I don’t think the parent claimed that beliefs are genetic or even that they are 100% heritable; only that conservative, religious populations have higher fertility rates and consequently the next generation will disproportionately come from a conservative, religious background. Many liberal atheists also come from conservative religious backgrounds, for example. This much at least doesn’t seem very controversial to me.
