4th cousins share one set of great-great-great grandparents. It's far beyond the range where it would cause genetic issues above what exist between any two random people. Even a single cousin marriage really doesn't increase the risk of genetic issues by a particularly concerning amount, it's only in communities with either repeated cousin marriage or where closer relatives are reproducing that there's a problem. I don't even know any of my second cousins. Fourth? Forget it. This is genuinely not something we should be wasting our time on.

For some perspective, about half of the world allows cousin marriage, some with restrictions. That includes most of Europe, multiple states in the USA, Canada, Mexico, Australia, New Zealand, and Japan. It also includes nations in Asia, Africa, and south America. There are ethical concerns regarding consent with first cousin marriage due to the close relationship and I don't actually think it should be legal, if only for that reason. We don't allow siblings with no direct relationship (adopted, blended families where both partners have kids from previous relationships) to be romantically involved either and that's obviously not because of the risks of inbreeding.

People massively overestimate the risks of inbreeding, historically a lot of reproduction was happening between first cousins, because until just a few hundred years ago most of the people you knew would be, at best, second or third cousins. The real horror stories only really happen with multiple generations of incest between cousins and siblings.

TL;dr: there's certainly an argument for banning first cousin marriage on the basis of "why even take the risk?". But that is absolutely not a basis for banning more distant relatives, because you are no longer taking any real measurable risk. There's a possibility for genetic issues to pop up between any two random people in the world and, once a couple is more distantly related than first cousins, the "risk" introduced by "inbreeding" (fourth cousins reproducing is absolutely not inbreeding) is dwarfed by the random risk any two individuals have.

[–] queermunist@lemmy.ml 3 points 21 hours ago (1 children)

My concern are power dynamics. A relationship between 4th cousins that happens entirely by accident is one thing, but for a lot of human history those kinds of relationships were arranged by the parents or by the family patriarch. That's not something we want.

[–] Blakey@hexbear.net 8 points 21 hours ago (2 children)

I addressed the issue of power dynamics between first cousins, but I am talking to someone who thinks fourth cousin relationships should be banned. There just is not a higher likelihood of an improper power imbalance in a fourth cousin relationship than between a pair of randoms, absent some extremely unusual family structures. Again, do you even know any of your fourth cousins? I don't even know any of my second cousins! I could sit down, think about it, and tell you all my first cousins, but nothing more distant than that.

[–] Damarcusart@hexbear.net 5 points 20 hours ago

but I am talking to someone who thinks fourth cousin relationships should be banned.

They said closer than fourth cousins though? So it's third cousins they're talking about being banned, not fourth cousins.

[–] queermunist@lemmy.ml 4 points 20 hours ago (1 children)

It probably doesn't need to be banned, but maybe monitored? The fact that I don't know any of my fourth cousins is exactly why the first thing that came to my mind was "arranged marriage." Just check, make sure no one got sold to another family for a dowry.

[–] Blakey@hexbear.net 4 points 20 hours ago (1 children)

But again, the situation would be literally no better without a fourth cousin relationship. The fact that the couple may be fourth cousins is a total red herring, it's got nothing to do with what's wrong with that situation. Yes, a familial relationship is often an aspect of an organised marriage, but selling someone to another family for a dowry with no blood relationship between the couple of any degree is exactly the same as between fourth cousins. I don't know why you are bringing the single shared pair of great, great, great grandparents into the scenario, it simply isn't significant in any way.

[–] queermunist@lemmy.ml 3 points 19 hours ago* (last edited 19 hours ago) (1 children)

Arranged marriages are often between cousins though? It's a way to preserve family wealth and maintain cultural values in small communities and carry on family tradition. Maybe I'm just jumping to conclusions idk it just seems like a red flag to me.

[–] Blakey@hexbear.net 3 points 17 hours ago

Sure, i get that, just doesn't seem like a particularly useful proxy.