Do you believe there are genetic issues that come from incest?
I am pretty sure that Orthodoxy has prohibitions against cousin incest as well.
Islam though, and especially some Islamic states are far more willing to tolerate it for various reasons and it has its downsides.
On the other hand, Ashkenazi Jews who are supposed to have the highest group IQ are fine with it to a much greater degree.
In harsher selection conditions people that suffer the downsides, as in sickle cell anemia with the Ashkenazis die out, and the positive reinforcement of recessive genes that boost intelligence get reinforced, at least according to Joly Heretic.
However, genetics is not the only reason why some societies have better work ethics and innovate more.
This is a fair point: the tragedy of prosperity is real. Why do agriculture when there's plentiful food to hunt/gather? Hardship is what makes civilization necessary. On top of that, if we look at the policies of the places, they are designed for handouts, plus Southern Italy has the OG Mafia.
It is not just that, a warmer climate also makes it harder to work and makes you pretty lazy.
Try building stuff in 35+ degrees Celsius heat and see how it affects you, for instance.
Another thing that no one in this discussion has noticed is that most of Eastern Europe was under frequent attack from outside forces.
If you go back about 800 - 900 years for example, the East had far more stability and economic prosperity, to the point where the West saw the Byzantine empire as a bunch of rich degenerates.
The various Rus principalities were also fairly free and prosperous before the mongol invasions, and the Polish-Lithuanian commonwealth was also quite rich.
The Southern part of Italy was also raided far more often than the north.
So, I'd say climate, geographic connectivity which permits trade and communication, and not getting invaded and subjugated too often all play a major role, certainly a bigger one than something the Pope once did.
I have to point out that "the end result of the various Euro Royal lines" is basically the worst possible case for incest, representing the result of hundreds of years of repeatedly inbreeding a small, homogenous population which was also shielded from most natural selection. And even then, only certain specific specimens out of those lines were notably unfit.
The degree to which less direct, less generationally consistent, and less sheltered incest amplifies genetic malformations is vastly less than imagined, which is exactly *why* anti-incest laws vary so widely from jurisdiction to jurisdiction.
TL;DR: While there is a scientific basis for saying that extreme incest is bad, there isn't actually a lot of data for *how* much incest is too much.
Exactly, the suitability of people with bad recessive genes goes up with social affluence.
IIRC there was someone theorizing that the prohibition of distant cousin marriage in Christianity came about because they wanted to break up the very powerful extended families, like the clans in places like Scotland and England and the large, powerful Familias that existed in Rome.
And here we go into my next hot take about history, namely that Christianity was pushed by roman elites in an attempt to make the empire more homogeneous, break up extended familial and ethnic loyalties, and centralize power in one person.
So, yeah, Christianity was the GloboHomo/WEF project of its day.